Water

Editorial

11 pages, 230 KiB

Open AccessEditorial

A Review on Applications of Remote Sensing and Geographic Information Systems (GIS) in Water Resources and Flood Risk Management

by Xianwei Wang^1,*

and Hongjie Xie^2,*

¹ School of Geography and Planning, and Guangdong Key Laboratory for Urbanization and Geo-Simulation, Sun Yat-Sen University, Guangzhou 510275, China

² Department of Geological Sciences, University of Texas at San Antonio, San Antonio, TX 78249, USA

Water 2018, 10(5), 608; https://doi.org/10.3390/w10050608 - 7 May 2018

Cited by 164 | Viewed by 27331

Abstract

Water is one of the most critical natural resources that maintain the ecosystem and support people’s daily life. Pressures on water resources and disaster management are rising primarily due to the unequal spatial and temporal distribution of water resources and pollution, and also [...] Read more.

Water is one of the most critical natural resources that maintain the ecosystem and support people’s daily life. Pressures on water resources and disaster management are rising primarily due to the unequal spatial and temporal distribution of water resources and pollution, and also partially due to our poor knowledge about the distribution of water resources and poor management of their usage. Remote sensing provides critical data for mapping water resources, measuring hydrological fluxes, monitoring drought and flooding inundation, while geographic information systems (GIS) provide the best tools for water resources, drought and flood risk management. This special issue presents the best practices, cutting-edge technologies and applications of remote sensing, GIS and hydrological models for water resource mapping, satellite rainfall measurements, runoff simulation, water body and flood inundation mapping, and risk management. The latest technologies applied include 3D surface model analysis and visualization of glaciers, unmanned aerial vehicle (UAV) video image classification for turfgrass mapping and irrigation planning, ground penetration radar for soil moisture estimation, the Tropical Rainfall Measuring Mission (TRMM) and the Global Precipitation Measurement (GPM) satellite rainfall measurements, storm hyetography analysis, rainfall runoff and urban flooding simulation, and satellite radar and optical image classification for urban water bodies and flooding inundation. The application of those technologies is expected to greatly relieve the pressures on water resources and allow better mitigation of and adaptation to the disastrous impact of droughts and flooding. Full article

(This article belongs to the Special Issue Applications of Remote Sensing/GIS in Water Resources and Flooding Risk Managements)

Research

Jump to: Editorial, Review, Other

14 pages, 1872 KiB

Open AccessArticle

Occurrences and Ecotoxicological Risk Assessment of Heavy Metals in Surface Sediments from Awash River Basin, Ethiopia

by Niguse Bekele Dirbaba^1,2, Xue Yan^2,3, Hongjuan Wu^1,*, Luanettee’ Lydia Colebrooke¹ and Jun Wang^2,3,*

¹ School of Environmental and Science and Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan 430074, China

² Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China

³ Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan 430074, China

Water 2018, 10(5), 535; https://doi.org/10.3390/w10050535 - 24 Apr 2018

Cited by 22 | Viewed by 6234

Abstract

Like many areas in developing nations, rapid population growth, a high urbanization rate, and poor waste management practices have been observed in the Awash River Basin. Moreover, no comprehensive study has been conducted in this basin to evaluate sediment contamination with heavy metals. [...] Read more.

Like many areas in developing nations, rapid population growth, a high urbanization rate, and poor waste management practices have been observed in the Awash River Basin. Moreover, no comprehensive study has been conducted in this basin to evaluate sediment contamination with heavy metals. About 46 sampling locations were considered to study heavy metal concentrations, distributions, pollution levels, and potential ecological risks associated with these contaminants. The results indicate that average concentrations of all metals have exceeded their respective background values except Pb and Hg. A comparison with similar studies also revealed that sediments from the Awash River Basin had a high average value for Cd. The mean enrichment values of heavy metals increased in the order of Hg < As < Pb < Ni < Cu < Cr < Zn < Cd. Multivariate analysis revealed that Ni and Cu had common sources. The average potential ecological risk index (ERI = 355.54) indicates high potential toxicity response in the study area. In general, surficial sediment contamination with heavy metals is causing high ecological hazards in Awash River Basin. This study sheds lights on the current level of contamination of heavy metals which are widely distributed across the sediments of rivers and streams of Awash River Basin. Full article

(This article belongs to the Special Issue Freshwater Quality as a Driver of Aquatic Ecosystem Health)

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15 pages, 1116 KiB

Open AccessArticle

Effect of Sand Mulches of Different Particle Sizes on Soil Evaporation during the Freeze–Thaw Period

by Huijun Feng¹, Junfeng Chen^1,*

, Xiuqing Zheng^1,*, Jing Xue¹, Chunyan Miao^1,2, Qi Du³ and Yongxin Xu^1,4

¹ College of Water Resources Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China

² First Hydrogeology and Engineering Geology Team of Shanxi Province, Taiyuan 030024, China

³ Taigu Water Balance Experimental Field, Bureau of Hydrology and Water Resources Survey of Shanxi Province, Taigu 030800, China

⁴ Department of Earth Sciences, University of the Western Cape, Private Bag X17, Bellville, Cape Town 7535, South Africa

Water 2018, 10(5), 536; https://doi.org/10.3390/w10050536 - 24 Apr 2018

Cited by 18 | Viewed by 4279

Abstract

Reducing ineffective evaporation is a feasible means to improve water use efficiency in agriculture, especially in arid and semi-arid areas. A field experiment assessed the impact of sand mulches (1-cm thickness) with a particle size of 0.5–1.5 mm (XS) and 1.5–2.0 mm (CS) [...] Read more.

Reducing ineffective evaporation is a feasible means to improve water use efficiency in agriculture, especially in arid and semi-arid areas. A field experiment assessed the impact of sand mulches (1-cm thickness) with a particle size of 0.5–1.5 mm (XS) and 1.5–2.0 mm (CS) on soil evaporation during winter in Northern China. Results showed that CS and XS increased by at least 11.93% and 14.92% compared to bare soil (LD), respectively. However, the sand mulches showed significant distinctions in soil evaporation at different stages. Soil evaporation was the highest in LD, while CS evaporated the least in the unstable freezing stage (P1) and stable freezing stage (P2); in the thawing stage (P3), XS evaporated the most, while LD evaporated the least. Ten factors affecting evaporation were analyzed using the principal component analysis method to elaborate the mechanisms of soil evaporation. Mean soil moisture at depths from 0 to 15 cm was a factor that affected the evaporation of XS and CS in the test. Soil moisture was evaporated by vapor when the frost penetration was dense and the frost impeded the vapor movement. The evaporation rates were steady and weak in this period, and soil moisture had slight impact on soil evaporation, especially XS and CS treatment with higher water content at the surface. The research is significant for preventing evaporation and the improvement of water-use efficiency. Full article

(This article belongs to the Section Water Resources Management, Policy and Governance)

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20 pages, 7734 KiB

Open AccessArticle

Analysis of Current and Future Water Demands in the Upper Indus Basin under IPCC Climate and Socio-Economic Scenarios Using a Hydro-Economic WEAP Model

by Ali Amin^1,*, Javed Iqbal¹, Areesha Asghar¹ and Lars Ribbe²

¹ Institute of Geographical Information System, School of Civil and Environmental Engineering, National University of Sciences and Technology, Islamabad 44000, Pakistan

² Integrated Land and Water Resources Management in the Tropics and Subtropics, Technology Arts Sciences TH Köln, 50679 Köln, Germany

Water 2018, 10(5), 537; https://doi.org/10.3390/w10050537 - 24 Apr 2018

Cited by 77 | Viewed by 12237

Abstract

Pakistan is currently facing physical and economic water scarcity issues that are further complicated by the rapid increase in its population and by climate change. Many studies have focused on the physical water scarcity using hydrological modeling and the measurement of the impact [...] Read more.

Pakistan is currently facing physical and economic water scarcity issues that are further complicated by the rapid increase in its population and by climate change. Many studies have focused on the physical water scarcity using hydrological modeling and the measurement of the impact of climate change on water resources in the Upper Indus Basin (UIB). However, few studies have concentrated on the importance of the economic water scarcity, that is, the water management issue under the looming impacts of climate change and the population explosion of Pakistan. The purpose of this study is to develop a management strategy which helps to achieve water security and sustainability in the Upper Indus Basin (UIB) with the help of different socio-economic and climate change scenarios using WEAP (Water Evaluation and Planning) modeling. The streamflow data of five sub-basins (Gilgit, Hunza, Shigar, Shyok, and Astore) and the entire Upper Indus Basin (UIB) were calibrated (2006–2010) and validated (2011–2014) in the WEAP model. The coefficient of determination and Nash Sutcliffe values for the calibration period ranged from 0.81–0.96. The coefficient of determination and the Nash Sutcliffe values for the validation period ranged from 0.85–0.94. After the development of the WEAP model, the analysis of the unmet water demand and percent coverage of the water demand for the period of 2006–2050 was computed. Different scenarios were generated for external driving factors (population growth, urbanization, and living standards) and the impact of climate change to evaluate their effect on the current water supply system. The results indicated that the future unmet water demand is likely to reach 134 million cubic meters (mcm) by the year 2050 and that the external driving factors are putting more pressure on the supply service. This study further explores the importance of proposed dams (likely to be built until 2025) by WAPDA (Water and Power Development Authority). These dams will decrease the unmet water demand by 60% in the catchment. The water demands under four scenarios (the reference, moderate future-1, moderate future-2, and management scenarios) were compared. The management scenario analysis revealed that 80% of the water demand coverage could be achieved by the year 2023, which could help in developing sustainable water governance for the catchment. Full article

(This article belongs to the Section Water Resources Management, Policy and Governance)

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15 pages, 6378 KiB

Open AccessArticle

Water Footprints of Vegetable Crop Wastage along the Supply Chain in Gauteng, South Africa

by Betsie Le Roux¹

, Michael Van der Laan^1,*, Teunis Vahrmeijer¹

, John G. Annandale¹

and Keith L. Bristow²

¹ Department of Plant and Soil Sciences, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa

² CSIRO Agriculture & Food, PMB Aitkenvale, Townsville, QLD 4814, Australia

Water 2018, 10(5), 539; https://doi.org/10.3390/w10050539 - 24 Apr 2018

Cited by 18 | Viewed by 5585

Abstract

Food production in water-scarce countries like South Africa will become more challenging in the future because of the growing population and intensifying water shortages. Reducing food wastage is one way of addressing this challenge. The wastage of carrots, cabbage, beetroot, broccoli and lettuce, [...] Read more.

Food production in water-scarce countries like South Africa will become more challenging in the future because of the growing population and intensifying water shortages. Reducing food wastage is one way of addressing this challenge. The wastage of carrots, cabbage, beetroot, broccoli and lettuce, produced on the Steenkoppies Aquifer in Gauteng, South Africa, was estimated for each step along the supply chain from the farm to the consumer. Water footprints for these vegetables were used to determine the volume of water lost indirectly as a result of this wastage. Highest percentage wastage occurs at the packhouse level, which is consistent with published literature. Some crops like lettuce have higher average wastage percentages (38%) compared to other crops like broccoli (13%) and cabbage (14%), and wastage varied between seasons. Care should therefore be taken when applying general wastage values reported for vegetables. The classification of “waste” presented a challenge, because “wasted” vegetables are often used for other beneficial purposes, including livestock feed and composting. It was estimated that blue water lost on the Steenkoppies Aquifer due to vegetable crop wastage (4 Mm³ year⁻¹) represented 25% of the estimated blue water volume that exceeded sustainable limits (17 Mm³ year⁻¹). Full article

(This article belongs to the Special Issue Progress in Water Footprint Assessment)

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15 pages, 2718 KiB

Open AccessArticle

On the Relationship between Aquatic Plant Stem Characteristics and Drag Force: Is a Modeling Application Possible?

by Anna Maria Łoboda¹

, Mikołaj Karpiński¹ and Robert Józef Bialik^2,*

¹ Institute of Geophysics, Polish Academy of Sciences, Księcia Janusza 64, 01-452 Warsaw, Poland

² Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland

Water 2018, 10(5), 540; https://doi.org/10.3390/w10050540 - 24 Apr 2018

Cited by 15 | Viewed by 6381

Abstract

This paper presents a basic model that shows the relationship between the diameter of a stem and its flexural rigidity. The model was developed from experimental measurements of biomechanical traits (i.e., tensile and bending traits like maximum forces, stresses, moduli of elasticity, flexural [...] Read more.

This paper presents a basic model that shows the relationship between the diameter of a stem and its flexural rigidity. The model was developed from experimental measurements of biomechanical traits (i.e., tensile and bending traits like maximum forces, stresses, moduli of elasticity, flexural rigidity, strain) of three freshwater macrophyte species (Elodea canadensis Michx., Potamogeton pectinatus L., and P. crispus L.), reflecting the seasonal changes in plant biomechanics throughout the vegetative season. These were obtained with the use of a bench-top testing machine in 2016 and 2017. The presented calculations are based on the ratio of drag-to-bending forces, in which the flexural rigidity plays a key role. The proposed model has the form EI = ad^b, and two approaches based on a regression analysis were applied to determine the parameters of the model—a and b. In the first method, the parameters were identified separately for each day of measurement, while in the second method, the coefficient b was calculated for all data from all days as a unified number for individual plants. The results suggest that coefficient b may provide information about the proportion of changes in drag forces depending on plant stiffness. The values of this coefficient were associated with the shape of the stem cross-section. The more circular the cross-section, the closer the value of the parameter was to 1. The parameter values were 1.60 for E. canadensis, 1.98 for P. pectinatus, and 2.46 for P. crispus. Moreover, this value also depended on the density of the cross-section structure. Most of the results showed that with an increase in stem diameter, the ratio between the drag and bending forces decreased, which led to fewer differences between these two forces. The model application may be introduced in many laboratory measurements of flow–biota interactions as well as in aquatic plant management applications. The implementation of these results in control methods for hydrophytes may help in mitigating floods caused by increases to a river channel’s resistance due to the occurrence of plants. Full article

(This article belongs to the Special Issue Advances in Ecological Water System Modeling: Integration and Leanification as a Basis for Application in Environmental Management)

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15 pages, 2418 KiB

Open AccessArticle

Community-Based Monitoring in Response to Local Concerns: Creating Usable Knowledge for Water Management in Rural Land

by Adriana C. Flores-Díaz^*

, Alexander Quevedo Chacón

, Rosaura Páez Bistrain, M. Isabel Ramírez and Alejandra Larrazábal

Centro de Investigaciones en Geografía Ambiental, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro 8701 ExHda La Huerta, ZP 58190 Morelia City, Michoacán, Mexico

Water 2018, 10(5), 542; https://doi.org/10.3390/w10050542 - 24 Apr 2018

Cited by 19 | Viewed by 7187

Abstract

Water resources around the world are being affected by increasing demand for human consumption as well as by industrial and agricultural use. Water quality has an impact on our quality of life, so effective monitoring provides the necessary data to allow decision makers [...] Read more.

Water resources around the world are being affected by increasing demand for human consumption as well as by industrial and agricultural use. Water quality has an impact on our quality of life, so effective monitoring provides the necessary data to allow decision makers to address critical water-related issues. This study (1) analyzes water knowledge generated by a community-based water monitoring (CBWM) network within a world heritage site; (2) discusses the extent to which monitoring responds to community concerns about water; and (3) indicates challenges in the generation of local usable knowledge. Using information generated over 6.5 years by a local monitoring network, we calculated a water quality index (WQI) and generated a time-series analysis using the breaks for additive season and trend (Bfast) algorithm. Results were grouped by specific community and institutional concerns about water. Springs under good management practices had low pollution levels, while others used for drinking and recreation had high fecal bacterial counts. Monitoring provided data about Escherichia coli counts exceeding legal limits, and about conditions of alkalinity and dissolved oxygen that represent a risk for the freshwater ecosystems. This study demonstrates how CBWM schemes can be a means of generating knowledge of water resources that can enhance the understanding of water dynamics and inform users’ decisions at local–regional levels. Full article

(This article belongs to the Section Water Resources Management, Policy and Governance)

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15 pages, 1862 KiB

Open AccessArticle

How Unusual Was 2015 in the 1984–2015 Period of the North Cascade Glacier Annual Mass Balance?

by Mauri S. Pelto

Environmental Science, Nichols College, Dudley, MA 01571, USA

Water 2018, 10(5), 543; https://doi.org/10.3390/w10050543 - 24 Apr 2018

Cited by 17 | Viewed by 6416

Abstract

In 1983, the North Cascade Glacier Climate Project (NCGCP) began the annual monitoring of the mass balance on 10 glaciers throughout the range, in order to identify their response to climate change. Annual mass balance (Ba) measurements have continued on seven original glaciers, [...] Read more.

In 1983, the North Cascade Glacier Climate Project (NCGCP) began the annual monitoring of the mass balance on 10 glaciers throughout the range, in order to identify their response to climate change. Annual mass balance (Ba) measurements have continued on seven original glaciers, with an additional two glaciers being added in 1990. The measurements were discontinued on two glaciers that had disappeared and one was that had separated into several sections. This comparatively long record from nine glaciers in one region, using the same methods, offers some useful comparative data in order to place the impact of the regional climate warmth of 2015 in perspective. The mean annual balance of the NCGCP glaciers is reported to the World Glacier Monitoring Service (WGMS), with two glaciers, Columbia and Rainbow Glacier, being reference glaciers. The mean Ba of the NCGCP glaciers from 1984 to 2015, was −0.54 m w.e.a⁻¹ (water equivalent per year), ranging from −0.44 to −0.67 m w.e.a⁻¹ for individual glaciers. In 2015, the mean Ba of nine North Cascade glaciers was −3.10 m w.e., the most negative result in the 32-year record. The correlation coefficient of Ba was above 0.80 between all North Cascade glaciers, indicating that the response was regional and not controlled by local factors. The probability of achieving the observed 2015 Ba of −3.10 is 0.34%. Full article

(This article belongs to the Section Hydrology)

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19 pages, 2329 KiB

Open AccessArticle

Impacts of Land Use Change and Summer Monsoon on Nutrients and Sediment Exports from an Agricultural Catchment

by Kiyong Kim^1,*, Bomchul Kim², Jaesung Eum², Bumsuk Seo², Christopher L. Shope³

and Stefan Peiffer¹

¹ Department of Hydrology, University of Bayreuth, 95440 Bayreuth, Germany

² Department of Environmental Science, Kangwon National University, Chuncheon 24341, Korea

³ Department of Environmental Quality, Division of Water Quality, Salt Lake City, UT 84116, USA

Water 2018, 10(5), 544; https://doi.org/10.3390/w10050544 - 24 Apr 2018

Cited by 25 | Viewed by 5745

Abstract

Agricultural non-point source (NPS) pollution is a major concern for water quality management in the Soyang watershed in South Korea. Nutrients (phosphorus and nitrogen), organic matter, and sediment exports in streams were estimated in an agricultural catchment (Haean catchment) for two years. The [...] Read more.

Agricultural non-point source (NPS) pollution is a major concern for water quality management in the Soyang watershed in South Korea. Nutrients (phosphorus and nitrogen), organic matter, and sediment exports in streams were estimated in an agricultural catchment (Haean catchment) for two years. The stream water samples were taken in dry and rainy seasons to evaluate the effect of monsoonal rainfall on pollutants exports. The influence of land use changes on NPS pollution was assessed by conducting a land use census and comparing the NPS characteristic exports. Total phosphorus (TP), suspended solids (SS), biochemical oxygen demand (BOD), and chemical oxygen demand (COD) increased dramatically in rainy seasons. Land uses were changed during the study period. Dry fields and rice paddies have decreased distinctively while orchard (apple, grape, and peach) and ginseng crops showed an increase within the catchment. The TP and SS loading decreased in the streams in 2010 compared to the loading in 2009 while the BOD and NO₃⁻ did not show distinct significant change. In this study, monsoonal driven rainfalls increased exports of agricultural NPS pollutants into streams. Land use change (mostly crop and paddy fields to orchards and ginseng fields) remarkably mitigated TP and SS exports into the streams. Full article

(This article belongs to the Section Water Quality and Contamination)

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22 pages, 531 KiB

Open AccessArticle

Sustainable Urban Water Management under a Changing Climate: The Role of Spatial Planning

by Anna Hurlimann^1,* and Elizabeth Wilson²

¹ Faculty of Architecture Building and Planning, The University of Melbourne, Melbourne, VIC 3010, Australia

² Faculty of Technology Design and Environment, Oxford Brookes University, Oxford OX3 0BP, UK

Water 2018, 10(5), 546; https://doi.org/10.3390/w10050546 - 25 Apr 2018

Cited by 54 | Viewed by 11262

Abstract

The provision of a sustainable supply of water is an increasingly difficult task to achieve in many urban environments. This arises because of pressures related to population growth and increased per capita demand for water. Additionally, climate change is impacting the natural cycle [...] Read more.

The provision of a sustainable supply of water is an increasingly difficult task to achieve in many urban environments. This arises because of pressures related to population growth and increased per capita demand for water. Additionally, climate change is impacting the natural cycle of water in many locations, with a significant impact projected for the future. Many scholars advocate ‘sustainable urban water management’ (SUWM) as an approach that can address the root causes of these challenges. Yet the implementation of SUWM and adaptation to climate change in the urban water sector remains limited. This paper argues that spatial planning provides tools and processes that can facilitate the full implementation of SUWM goals, and adaptation to climate change. The potential of spatial planning to achieve SUWM, including sustainable urban water supply management through both supply and demand end initiatives, in light of climate change, is discussed. A framework is developed to consider a broad range of spatial planning interventions that can facilitate adaptation to climate change and SUWM concurrently. The paper provides information and tools to assist water planners achieve SUWM and a well-adapted water sector and urban environment, in an integrated, holistic and comprehensive manner, to meet future water supply needs. Achieving these goals will need collaborative activities across multiple built environment disciplines. Future research activities to advance these goals are outlined. Full article

(This article belongs to the Special Issue Technologies and Interventions to Support Sustainable Urban Water Management)

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19 pages, 3414 KiB

Open AccessFeature PaperArticle

Optimizing Re-Chlorination Injection Points for Water Supply Networks Using Harmony Search Algorithm

by Do Guen Yoo¹, Sang Myoung Lee², Ho Min Lee³, Young Hwan Choi⁴ and Joong Hoon Kim^5,*

¹ Department of Civil Engineering, The University of Suwon, Gyeonggi-do 18323, Korea

² K-Water, 200, Sintanjin-ro, Daedeok-gu, Daegeon 34350, Korea

³ Research Center for Disaster Prevention Science and Technology, Korea University, Seoul 02841, Korea

⁴ Department of Civil, Environmental and Architectural Engineering, Korea University, Seoul 02841, Korea

⁵ School of Civil, Environmental and Architectural Engineering, Korea University, Anam-ro 145, Seongbuk-gu, Seoul 02841, Korea

Water 2018, 10(5), 547; https://doi.org/10.3390/w10050547 - 25 Apr 2018

Cited by 23 | Viewed by 6248

Abstract

In order to achieve the required residual chlorine concentration at the end of a water network, the installation of a re-chlorination facility for a high-quality water supply system is necessary. In this study, the optimal re-chlorination facility locations and doses were determined for [...] Read more.

In order to achieve the required residual chlorine concentration at the end of a water network, the installation of a re-chlorination facility for a high-quality water supply system is necessary. In this study, the optimal re-chlorination facility locations and doses were determined for real water supply systems, which require maintenance in ord3r to ensure proper residual chlorine concentrations at the pipeline under the present and future conditions. The harmony search algorithm (HSA), which is a meta-heuristic optimization technique, was used for the optimization model. This method was applied to two water supply systems in South Korea and was verified through case studies using different numbers of re-chlorination points. The results show that the proposed model can be used as an efficient water quality analysis and decision making tool, which showed the optimal re-chlorination dose and little deviation in the spatial distribution. In addition, the HSA results are superior to those of the genetic algorithm (GA) in terms of the total injection mass with the same number of evaluations. Full article

(This article belongs to the Special Issue Water Networks Management: New Perspectives)

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11 pages, 5680 KiB

Open AccessArticle

Antibiotic Resistance and Extended-Spectrum Beta-Lactamase Production of Escherichia coli Isolated from Irrigation Waters in Selected Urban Farms in Metro Manila, Philippines

by Pierangeli G. Vital^1,2,*, Enrico S. Zara¹, Cielo Emar M. Paraoan¹, Ma. Angela Z. Dimasupil¹, Joseth Jermaine M. Abello¹, Iñigo Teodoro G. Santos¹ and Windell L. Rivera^1,2

¹ Institute of Biology, College of Science, University of the Philippines Diliman, Quezon City 1101, Philippines

² Natural Sciences Research Institute, University of the Philippines Diliman, Quezon City 1101, Philippines

Water 2018, 10(5), 548; https://doi.org/10.3390/w10050548 - 25 Apr 2018

Cited by 37 | Viewed by 16422

Abstract

Highly-polluted surface waters are increasingly used for irrigation in different agricultural settings because they have high nutrient content and are readily available. However, studies showed that they are reservoirs for the emergence and dissemination of antibiotic-resistant bacteria in the environment. In this study, [...] Read more.

Highly-polluted surface waters are increasingly used for irrigation in different agricultural settings because they have high nutrient content and are readily available. However, studies showed that they are reservoirs for the emergence and dissemination of antibiotic-resistant bacteria in the environment. In this study, the resistance of 212 Escherichia coli isolates from irrigation water, soil, and vegetables in selected urban farms in Metro Manila, Philippines was evaluated. Results showed that antibiotic resistance was more prevalent in water (67.3%) compared to soil (56.4%) and vegetable (61.5%) isolates. Resistance to tetracycline was the highest among water (45.6%) and vegetable (42.3%) isolates while ampicillin resistance was the highest among soil isolates (33.3%). Multidrug-resistant (MDR) isolates were also observed and they were more prevalent in water (25.3%) compared to soil (2.8%) and vegetable (8.4%) isolates. Interestingly, there are patterns of antibiotic resistance that were common to isolates from different samples. Extended-spectrum beta-lactamase production (ESBL) was also investigated and genes were observed to be present in 13 isolates. This provides circumstantial evidence that highly-polluted surface waters harbor antibiotic-resistant and MDR E. coli that may be potentially transferred to primary production environments during their application for irrigation purposes. Full article

(This article belongs to the Special Issue Antimicrobial Resistance in Environmental Waters)

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10 pages, 1820 KiB

Open AccessArticle

Precision Irrigation Scheduling Using ECH₂O Moisture Sensors for Lettuce Cultivated in a Soilless Substrate Culture

by Zhigang Liu^1,* and Qinchao Xu²

¹ School of the Environment and Safety Engineering, Institute of Environment Health and Ecological Security, Jiangsu University, Zhenjiang 212013, China

² College of Engineering, Huazhong Agriculture University, Wuhan 430070, China

Water 2018, 10(5), 549; https://doi.org/10.3390/w10050549 - 25 Apr 2018

Cited by 12 | Viewed by 5245

Abstract

Soilless culture has become an effective technique to avoid continuous cropping obstacles in protected horticulture. The reliable measurement of substrate moisture and a rational irrigation are difficult tasks because of the low water-holding capacity of the substrate. Our objectives were to study the [...] Read more.

Soilless culture has become an effective technique to avoid continuous cropping obstacles in protected horticulture. The reliable measurement of substrate moisture and a rational irrigation are difficult tasks because of the low water-holding capacity of the substrate. Our objectives were to study the irrigation scheduling based on the ECH₂O moisture sensor(EC-5), using a matched model of wetting pattern and lettuce root zone in the substrate under drip irrigation. The EC-5 sensor was designed to connect to a controller, and a threshold value of 0.14 cm³/cm³ was set for irrigation scheduling. The controller turned on the irrigation system via communication with a solenoid valve on the irrigation line and with the EC-5 sensor in response to a threshold value and stopped when the overlap area of the wetting pattern and crop root zone was more than 90%. The EC-5 sensors were installed at a horizontal distance from each plant and depth of 3 and 4 cm, respectively, under the substrate surface to the check substrate moisture for lettuce cultivation, and at (3,15) cm or (6,15) cm to monitor leakage. These parameters were determined by simultaneously considering the distance from the plants, the depths of effective root water extraction, and the region of substrate wetted volume under drip irrigation. Leakage occurred during each irrigation process, but the leakage ratewas15.7% lower than that of conventional irrigation, as a result of irrigation scheduling in the presence of the EC-5 sensors. Full article

(This article belongs to the Special Issue Advances in Agriculture Water Efficiency)

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29 pages, 32268 KiB

Open AccessFeature PaperArticle

Waves and Currents at a River Mouth: The Role of Macrovortices, Sub-Grid Turbulence and Seabed Friction

by Lorenzo Melito^*

, Matteo Postacchini

, Giovanna Darvini

and Maurizio Brocchini

Department of DICEA, Università Politecnica delle Marche; Via Brecce Bianche 12, 60131 Ancona, Italy

Water 2018, 10(5), 550; https://doi.org/10.3390/w10050550 - 25 Apr 2018

Cited by 8 | Viewed by 6129

Abstract

Numerical experiments of wave-current interaction have been performed to investigate the evolution and dissipation of horizontal large-scale vortical structures generated by differential wave breaking and current shearing at river mouths. Specific focus is on the role played by turbulence of scales smaller than [...] Read more.

Numerical experiments of wave-current interaction have been performed to investigate the evolution and dissipation of horizontal large-scale vortical structures generated by differential wave breaking and current shearing at river mouths. Specific focus is on the role played by turbulence of scales smaller than the water depth and by seabed friction on the dissipation of the mentioned macrovortices. The analysis reveals two regions of turbulence generation: at the river mouth, and along the curved seaward boundary of the shoal. In the latter zone, macrovortices are formed due to differential wave breaking induced by the sudden variation in water depth and enhanced by opposing currents which favour wave steepening. Such vortices are then advected towards the shore. Among the dissipative mechanisms, dissipation induced by seabed friction is deemed dominant, in particular in the most shallow waters of the shoal. Sub-grid turbulence dissipation, conversely, is more efficient offshore, although exerting some effect also over the shoal when supported by the continuous action of waves. Full article

(This article belongs to the Special Issue Turbulence in River and Maritime Hydraulics)

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15 pages, 11740 KiB

Open AccessArticle

Assessment of Excess Sludge Ultrasonic, Mechanical and Hybrid Pretreatment in Relation to the Energy Parameters

by Łukasz Skórkowski^*, Ewa Zielewicz, Artur Kawczyński and Bożena Gil

Institute of Water and Wastewater Engineering, Silesian University of Technology, Konarskiego 18A, 44-100 Gliwice, Poland

Water 2018, 10(5), 551; https://doi.org/10.3390/w10050551 - 25 Apr 2018

Cited by 14 | Viewed by 4416

Abstract

Anaerobic digestion is the most common stabilization process at large sewage treatment plants. To improve its effects, a sludge pre-conditioning process called disintegration is recommended. The aim of the presented study was to compare the direct effects of various types of mechanical disintegration, [...] Read more.

Anaerobic digestion is the most common stabilization process at large sewage treatment plants. To improve its effects, a sludge pre-conditioning process called disintegration is recommended. The aim of the presented study was to compare the direct effects of various types of mechanical disintegration, performed for the same excess sludge, in relation to the energy parameters and effectiveness of the process. Four different disintegration methods were used: mechanical disintegration in semi-technical and laboratory scale homogenizing mixers, ultrasonic disintegration (US) and combined (hybrid) process. The disintegration was performed for volumetric energy E_V = 4.67–100 kWh m⁻³, the results were evaluated based on dispersion (kd_COD, kd_CST), lysis (kd_SCOD), acidification (kd_VFA) and nutrient release (kd_TN, kd_TP) disintegration indicators. The statistical analysis of the results indicates the influence of disintegrator type (mixer/US/hybrid), scale (laboratory/semi-technical) and energy input on the direct results of disintegration. Hybrid disintegration delivered better direct results than two pre-treatment processes used separately. The efficiency of the hybrid process defined as the increase of the indicator (disintegration products—∆FCOD, ∆SCOD) per unit of energy was considerably higher than for a single stage disintegration process. Full article

(This article belongs to the Section Wastewater Treatment and Reuse)

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23 pages, 5135 KiB

Open AccessArticle

Simulation of Propagation and Run-Up of Three Dimensional Landslide-Induced Waves Using a Meshless Method

by Shih-Chun Hsiao¹, Ming-Yang Shih¹ and Nan-Jing Wu^2,*

¹ Department of Hydraulic and Ocean Engineering, National Cheng Kung University, Tainan 701, Taiwan

² Department of Civil and Water Resources Engineering, National Chiayi University, Chiayi 600, Taiwan

Water 2018, 10(5), 552; https://doi.org/10.3390/w10050552 - 25 Apr 2018

Cited by 4 | Viewed by 3572

Abstract

In this study, a meshless numerical model for the simulation of tsunamis generated by submerged landslides was developed. The phenomena were treated as free surface potential flows governed by the Laplace equation. By using a predictor-corrector time marching approach, the time dependent problem [...] Read more.

In this study, a meshless numerical model for the simulation of tsunamis generated by submerged landslides was developed. The phenomena were treated as free surface potential flows governed by the Laplace equation. By using a predictor-corrector time marching approach, the time dependent problem was transformed to a series of boundary value problems (BVP) while at each time step the BVP was solved by a meshless method which employed local polynomial collocation accompanying the weight-least-squares (WLS) approach. The model was validated by comparing the results with experimental data and other numerical results. Then, simulations were carried out in a widened numerical wave flume for the observation of edge waves along the shore. Full article

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15 pages, 417 KiB

Open AccessArticle

Rebuild by Design in Hoboken: A Design Competition as a Means for Achieving Flood Resilience of Urban Areas through the Implementation of Green Infrastructure

by Robert Šakić Trogrlić^1,*, Jeroen Rijke^2,3, Nanco Dolman⁴

and Chris Zevenbergen⁵

¹ School of Energy, Geoscience, Infrastructure and Environment, Institute for Infrastructure and Environment, Heriot-Watt University, Edinburgh EH14 4AS, UK

² Knowledge Centre Engineering and Society, HAN University of Applied Sciences, 6826 CC Arnhem, The Netherlands

³ Applied Research Centre Delta Areas and Resources, VHL University of Applied Sciences, #26a Larensteinselaan, 6882 CT Velp, The Netherlands

⁴ Royal HaskoningDHV, #47 Contactweg, 1090 GE Amsterdam, The Netherlands

⁵ Water Science & Engineering Department, IHE Delft Institute for Water Education, #7 Westvest, 2611 AX Delft, The Netherlands

Water 2018, 10(5), 553; https://doi.org/10.3390/w10050553 - 25 Apr 2018

Cited by 34 | Viewed by 8303

Abstract

The Rebuild by Design (RBD) competition was launched after the devastating impact of Hurricane Sandy, and the winning designs have put a significant emphasis on green infrastructure (GI) as a means of achieving flood resilience in urban areas. Previous research in the field [...] Read more.

The Rebuild by Design (RBD) competition was launched after the devastating impact of Hurricane Sandy, and the winning designs have put a significant emphasis on green infrastructure (GI) as a means of achieving flood resilience in urban areas. Previous research in the field of urban stormwater management indicates that wide-spread implementation of GI remains a challenge, largely due to a lack of understanding of the required governance approaches. Therefore, by using a case study of Hoboken, for which the winning design was developed, this paper explores whether RBD provides governance structures and processes needed for the uptake of GI. Semi-structured interviews and desk study provided the data for an analysis of the presence of factors for supporting the transformative governance needed to facilitate the uptake of innovative solutions. Results indicate that RBD brought a greater change in terms of governance processes when compared to governance structures. In Hoboken, RBD created a narrative for long-term change, put GI as a preferred solution for tackling multiple challenges, and strengthened the local political buy-in. However, pitfalls were observed, such as limited funding provision, lack of regulatory compliance, economic justification and large investments required from public and private parties. The absence of these factors can hinder the overall uptake of the GI solution. Even though the design competition presents a novel approach to the field of resilience development, further steps should be made in understanding how the RBD methodology can be adjusted to provide results of equal quality in different settings (e.g., less developed regions, different governance contexts). Full article

(This article belongs to the Special Issue Sponge Cities: Emerging Approaches, Challenges and Opportunities)

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20 pages, 4877 KiB

Open AccessArticle

Evaluation of the Spatiotemporal Variation of Sustainable Utilization of Water Resources: Case Study from Henan Province (China)

by Yizhen Jia^1,*

, Juqin Shen¹, Han Wang², Guanghua Dong¹

and Fuhua Sun¹

¹ Business School, Hohai University, Nanjing 211100, China

² School of Public Administration, Hohai University, Nanjing 211100, China

Water 2018, 10(5), 554; https://doi.org/10.3390/w10050554 - 25 Apr 2018

Cited by 23 | Viewed by 4817

Abstract

The evaluation of the sustainable utilization of water resources is an important factor to measure whether the water resources can support the local coordinated development of population, economy and environment. Our study used Henan Province as the research area, which has a relative [...] Read more.

The evaluation of the sustainable utilization of water resources is an important factor to measure whether the water resources can support the local coordinated development of population, economy and environment. Our study used Henan Province as the research area, which has a relative shortage of water resources (average water resources per capita, ≤400 m³). The Drivers, Pressures, State, Impact, Response (DPSIR) model was used to construct the evaluation index system, utilizing the entropy weight method and the Analytic Hierarchy Process (AHP) method to determine the index weight. The sustainable utilization of water resources in 18 cities of Henan Province from 2006 to 2015 was evaluated using the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) model. The results show a steady upward trend, from worst to general, but there is a great difference between each city. The overall level was still on the low side, and the influence of each subsystem in the comprehensive index of the sustainable utilization of water resources varies. The evaluation results are basically in line with the actual situation of economic and social development in Henan Province, which has a guiding significance for improving the level of sustainable utilization of water resources in the region. Full article

(This article belongs to the Section Water Resources Management, Policy and Governance)

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23 pages, 7578 KiB

Open AccessArticle

by Xianwei Wang^1,*

, Huijiao Chen¹ and Yaning Chen²

¹ School of Geography and Planning, and Guangdong Key Laboratory for Urbanization and Geo-Simulation, Sun Yat-sen University, Guangzhou 510275, China

² State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China

Water 2018, 10(5), 555; https://doi.org/10.3390/w10050555 - 25 Apr 2018

Cited by 5 | Viewed by 4842

Abstract

Studies have investigated the glacier projected area (2D Area) on a horizontal plane, which is much smaller than the glacier topographic surface extent (3D Area) in steep terrains. This study maps the glacier outline in Central Tianshan using Landsat images from four periods, [...] Read more.

Studies have investigated the glacier projected area (2D Area) on a horizontal plane, which is much smaller than the glacier topographic surface extent (3D Area) in steep terrains. This study maps the glacier outline in Central Tianshan using Landsat images from four periods, i.e., 1989, 2002, 2007 and 2015, by an object-based classification approach, and analyzes the glacier 2D and 3D area changes related to topographic factors based on Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global DEM data. This approach shows an accuracy of 90.8% for clean ice mapping. The derived clean ice outlines are in good agreement with the 2nd Chinese Glacier Inventory (CGI2) and the Global Land Ice Measurements from Space (GLIMS). The fields with a northern aspect receive the least surface solar radiation, leading to dominant existing glaciers. Glaciers are near evenly distributed in slope zones of 0° to 50° and have a mean slope angle of 28.8°, resulting in a 30.3% larger 3D area than the 2D area in 2015 in Central Tianshan. The glacier 2D area decreased by 404 km² (−8.1%) between 1989 and 2015, while the 3D area declined by 516 km² (−7.9%). The glacier 2D area showed a reduction of −1.8% between 1989 and 2002, −3.8% between 2002 and 2007, and −2.7% between 2007 and 2015, and these retreating rates closely responded to the variations of regional mean air temperature and precipitation. Topographically, most reductions occurred in elevation bands of 3000–4000 m and in slope zones of 10–20° and 40–50°, and in the eastern aspect fields. The northern Tekes River catchment had the largest shrinking rate of −17.0% (2D area), followed by the southern Karasu River (−14.2%) and Muzart River (−7.7%) catchments. In contrast, glaciers in the Kumerik/Aksu and Tailan River catchments in the Tuomuer region showed little change (−2%). Full article

(This article belongs to the Special Issue Applications of Remote Sensing and GIS in Hydrology)

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18 pages, 4812 KiB

Open AccessArticle

The Impact of Shrubby Floodplain Vegetation Growth on the Discharge Capacity of River Valleys

by Natalia Walczak^1,*, Zbigniew Walczak², Tomasz Kałuża¹, Mateusz Hämmerling¹ and Piotr Stachowski³

¹ Department of Hydraulic and Sanitary Engineering, Poznan University of Life Sciences, 60-637 Poznań, Poland

² Institute of Construction and Geoengineering, Poznan University of Life Sciences, 60-637 Poznań, Poland

³ Institute of Land Improvement, Environmental Development and Geodesy, Poznan University of Life Sciences, 60-637 Poznań, Poland

Water 2018, 10(5), 556; https://doi.org/10.3390/w10050556 - 25 Apr 2018

Cited by 15 | Viewed by 4368

Abstract

Willow bush growing in floodplains is a dominant form of vegetation in lowland river valleys due to the availability of water and light. Uncontrolled growth of this plant results in a lower capacity of floodplain areas. Vegetation can narrow the active width of [...] Read more.

Willow bush growing in floodplains is a dominant form of vegetation in lowland river valleys due to the availability of water and light. Uncontrolled growth of this plant results in a lower capacity of floodplain areas. Vegetation can narrow the active width of water flow, as well as change water flow velocities at hydrometric verticals falling within the floodplain and the main channel. This paper analyses the impact of long-term growth of willow shrubs on flow resistance coefficient values. Both an increase in the average diameter and the density characterised by the average distance between branches have a significant impact on reducing the flow. The adopted research variants were based on data on the growth rate of the most popular species and forms of willow found in the floodplains of the Warta River above the Jeziorsko reservoir. Two research scenarios were analysed, including data from 12 years, on the development of floodplain vegetation. The first scenario included only the change in diameter (vegetation grew on a cultivation plot), whereas the density remained constant. The second scenario investigated the inverse model—vegetation growing in an uncontrolled manner. The analysis of the tests proved the impact of various bush development scenarios on flow conditions. The results, referred to in the available research papers, indicated the importance of the dynamics of shrub development to the local flow conditions. It was stated that reduction in the flow, depending on the analysed scenario, could reach 45% for scenarios in which the only considered factor was the increase in diameter (at a constant density), and up to 70% in the case of increase in the density of vegetation. Thorough knowledge of this phenomenon may help manage and maintain natural river valleys. Full article

(This article belongs to the Section Water Quality and Contamination)

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16 pages, 5246 KiB

Open AccessArticle

The Application of a Multi-Beam Echo-Sounder in the Analysis of the Sedimentation Situation of a Large Reservoir after an Earthquake

by Zhong-Luan Yan^1,2, Lei-Lei Qin^1,2, Rui Wang^2,3, Jia Li², Xiao-Ming Wang⁴, Xi-Liang Tang⁴ and Rui-Dong An^2,*

¹ Postdoctoral Research Station, China Three Gorges Corporation, Beijing 100038, China

² State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China

³ Power China Chengdu Engineering Corporation Limited, Chengdu 610072, China

⁴ China Three Gorges Projects Development Co., Ltd., Chengdu 610094, China

Water 2018, 10(5), 557; https://doi.org/10.3390/w10050557 - 26 Apr 2018

Cited by 12 | Viewed by 6080

Abstract

The Wenchuan Earthquake took place in the upper reach catchment of the Min River. It resulted in large amounts of loose materials gathering in the river channel, leading to changes in the sediment transport system in this area. The Zipingpu Reservoir is the [...] Read more.

The Wenchuan Earthquake took place in the upper reach catchment of the Min River. It resulted in large amounts of loose materials gathering in the river channel, leading to changes in the sediment transport system in this area. The Zipingpu Reservoir is the last and the largest reservoir located in the upper reach of the Min River. It is near the epicenter and receives sediment from upstream. This paper puts forward a study on the reservoir sedimentation and storage capacity of the Zipingpu Reservoir, employing a multi-beam echo-sounder system in December 2012. Then, the data were merged with digital line graphics and shuttle radar topography mission data in ArcGIS to build a digital elevation model and triangulate the irregular network of Zipingpu Reservoir. Via the analysis of the bathymetric data, the results show the following: (1) The main channels of the reservoir gradually aggrade to a flat bottom from the deep-cutting valley. Sedimentation forms a reach with a W-shaped longitudinal thalweg profile and an almost zero slope reach in the upstream section of the reservoir due to the natural barrier induced by a landslide; (2) The loss ratios of the wetted cross-section surface are higher than 10% in the upstream section of the reservoir and higher than 40% in the natural barrier area; (3) Comparing the surveyed area storage capacity of December 2012 with March 2008, the Zipingpu Reservoir has lost 15.28% of its capacity at the dead storage water level and 10.49% of its capacity at the flood limit water level. Full article

(This article belongs to the Section Water Resources Management, Policy and Governance)

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20 pages, 1356 KiB

Open AccessArticle

Evapotranspiration Partition and Crop Coefficients of Tifton 85 Bermudagrass as Affected by the Frequency of Cuttings. Application of the FAO56 Dual K_c Model

by Paula Paredes¹

, Geraldo J. Rodrigues², Mirta T. Petry^2,*, Paula O. Severo², Reimar Carlesso² and Luis Santos Pereira¹

¹ Centro de Investigação em Agronomia, Alimentos, Ambiente e Paisagem (LEAF), Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal

² Centro de Ciências Rurais, Universidade Federal de Santa Maria, Cidade Universitária, Bairro Camobi, 97105-900 Santa Maria, RS, Brazil

Water 2018, 10(5), 558; https://doi.org/10.3390/w10050558 - 26 Apr 2018

Cited by 22 | Viewed by 5046

Abstract

This study aims to model the impacts of the frequency of cuttings of Tifton 85 bermudagrass on the dynamics of evapotranspiration (ET_c) and to derive crop coefficients appropriate for grass water management. Two seasons of experimentation were used with four different [...] Read more.

This study aims to model the impacts of the frequency of cuttings of Tifton 85 bermudagrass on the dynamics of evapotranspiration (ET_c) and to derive crop coefficients appropriate for grass water management. Two seasons of experimentation were used with four different cutting treatments which provided field data for calibration and validation of the soil water balance model SIMDualKc for all treatments. Cuttings were performed after the cumulative growth degree days (CGDD) attained 124 °C, 248 °C and 372 °C, thus from short to very long intervals between cuttings. SIMDualKc adopts the Food and Agriculture Organization (FAO) dual K_c approach for partitioning ET into crop transpiration and soil evaporation, thus providing for an assessment of their dynamics. All treatments were irrigated to avoid water stress. Grass ET_c was modelled adopting a K_cb curve to describe the ET variation for each cutting cycle, that is, using the FAO K_c curve that consists of a series of K_cb curves relative to each cutting cycle. Each individual K_cb curve consisted of three segments constructed when knowing the K_cb values at the initial, at the end of rapid growth, and at cutting, respectively K_{cb ini}, K_{cb gro} and K_{cb cut}. These K_cb values were first estimated using the equation relating K_cb to the density coefficient (K_d), which is computed from the fraction of ground cover (f_c) and canopy height (h) at the same dates. The goodness of fit indicators relative to the calibration and validation of the SIMDualKc model were rather good, with the normalized root mean square error (RMSE) ranging from 4.0% to 6.7% of the mean available soil water. As an example, the standard K_cb values obtained after model calibration relative to the cuttings treatment with CGDD of 248 °C are: K_{cb ini} = 0.86, K_{cb gro} = 0.91 and K_{cb cut} = 0.96. K_cb values were smaller when the frequency of cuts was larger because h and f_c were smaller, and were larger for reduced cuttings frequency since h and f_c were then larger. Because the soil was wet most of the time, the soil evaporation K_e varied little but its value was small due to the combined effects of the fraction of crop cover and plant litter covering the soil. The values of K_c = K_cb+K_e also varied little due to the influence of K_e and the K_c curve obtained a form different from the K_cb curves, and a single K_c value was adopted for each cutting frequency, e.g., K_c = 0.99 for the treatment with CGDD of 248 °C. Results of the soil water balance have shown that, during the experimental periods, likely due to the effects of the El Niño Southern Oscillation (ENSO), runoff and deep percolation exceeded ET_c. Moreover, the soil evaporation ratio was small: 14% in case of frequent cuttings and less for more spaced cuttings, thus with a transpiration ratio close to 90%, which indicates a very high beneficial consumptive water use, mainly when cuttings are not very frequent. Full article

(This article belongs to the Special Issue Innovation Issues in Water, Agriculture and Food)

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16 pages, 2586 KiB

Open AccessArticle

Influence of Straw Amendment on Soil Physicochemical Properties and Crop Yield on a Consecutive Mollisol Slope in Northeastern China

by Shaoliang Zhang^*

, Yao Wang and Qingsong Shen

College of Resources and Environment, Northeast Agricultural University, 600 Changjiang Street, XiangFang District, Harbin 150030, China

Water 2018, 10(5), 559; https://doi.org/10.3390/w10050559 - 26 Apr 2018

Cited by 27 | Viewed by 4849

Abstract

Straw amendment (SA) can be used to increase soil organic matter and decrease dioxide carbon emissions. However, the impact of SA on the crop yield is still subject to debate in different areas. In this study, soil temperature (ST), soil moisture (SM), soil [...] Read more.

Straw amendment (SA) can be used to increase soil organic matter and decrease dioxide carbon emissions. However, the impact of SA on the crop yield is still subject to debate in different areas. In this study, soil temperature (ST), soil moisture (SM), soil bulk density, soil-available-nitrogen (AN), soil-available-phosphorus (AP), crop growth and yield were measured in SA and NSA (no straw amendment) at slope positions of a 130-m-long consecutive Mollisol slope during the maize (Zea mays) growth stages in the North Temperate Zone of China. Compared with NSA, the influence of SA on ST and SM was not consistent, while AN typically increased on the top slope. However, SA conventionally increased AP, increased daily ST and monthly ST (2.4–7.9%), and increased daily SM and monthly SM (2.1–12.5%) on the back slope. SA increased crop yield by 1–9.8% and 55.6–105.1% on the top and back slopes, respectively. At the bottom, SA conventionally decreased ST (0.20–1.48 °C in July and August), SM (3.5–29.6% from May to August), AN and AP, and decreased crop yield (4.1–30.6%). In conclusion, SA changed the equilibrium of ST and SM, influenced the dynamics of AN and AP on the consecutive slopes, and increased yield on both the top and back slopes but decreased yield at the bottom. Full article

(This article belongs to the Special Issue Innovation Issues in Water, Agriculture and Food)

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23 pages, 3153 KiB

Open AccessArticle

Design Flood Estimation Methods for Cascade Reservoirs Based on Copulas

by Shenglian Guo^*

, Rizwan Muhammad, Zhangjun Liu, Feng Xiong and Jiabo Yin

State Key Laboratory of Water Resources and Hydropower Engineering Science, Hubei Provincial Collaborative Innovative Center for Water Resources Security, Wuhan University, Wuhan 430072, China

Water 2018, 10(5), 560; https://doi.org/10.3390/w10050560 - 26 Apr 2018

Cited by 28 | Viewed by 5116

Abstract

Reservoirs operation alters the natural flow regime at downstream site and thus has a great impact on the design flood values. The general framework of flood regional composition and Equivalent Frequency Regional Composition (EFRC) method are currently used to calculate design floods at [...] Read more.

Reservoirs operation alters the natural flow regime at downstream site and thus has a great impact on the design flood values. The general framework of flood regional composition and Equivalent Frequency Regional Composition (EFRC) method are currently used to calculate design floods at downstream site while considering the impact of the upstream reservoirs. However, this EFRC method deems perfect correlation between peak floods that occurred at one sub-basin and downstream site, which implicitly assumes that the rainfall and the land surface process are uniformly distributed for various sub-basins. In this study, the Conditional Expectation Regional Composition (CERC) method and Most Likely Regional Composition (MLRC) method based on copula function are proposed and developed under the flood regional composition framework. The proposed methods (i.e., CERC and MLRC) are tested and compared with the EFRC method in the Shuibuya-Geheyan-Gaobazhou cascade reservoirs located at Qingjiang River basin, a tributary of Yangtze River in China. Design flood values of the Gaobazhou reservoir site are estimated under the impact of upstream cascade reservoirs, respectively. Results show that design peak discharges at the Gaobazhou dam site have been significantly reduced due to the impact of upstream reservoir regulation. The EFRC method, not taking the actual dependence of floods occurred at various sub-basins into account; as a consequence, it yields an under-or overestimation of the risk that is associated with a given event in hydrological design. The proposed methods with stronger statistical basis can better capture the actual spatial correlation of flood events occurred at various sub-basins, and the estimated design flood values are more reasonable than the currently used EFRC method. The MLRC method is recommended for design flood estimation in the cascade reservoirs since its composition is unique and easy to implement. Full article

(This article belongs to the Special Issue Advances in Multivariate Analysis of Environmental Phenomena: Celebrating the 15th Anniversary of Copulas in Hydrology)

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16 pages, 4825 KiB

Open AccessArticle

Influence of Gravel-Bed Porosity and Grain Orientation on Bulk Flow Resistance

by Christy Ushanth Navaratnam^1,*

, Jochen Aberle^1,2, Jie Qin³

and Pierre-Yves Henry¹

¹ Department of Civil and Environmental Engineering, Norwegian University of Science and Technology (NTNU), S.P.Andersens veg 5, 7491 Trondheim, Norway

² Leichtweiß-Institut für Wasserbau, Technische Universität Braunschweig, 38106 Braunschweig, Germany

³ College of Harbour, Coastal and Offshore Engineering, Hohai University, Xikang road #1, Nanjing 210098, China

Water 2018, 10(5), 561; https://doi.org/10.3390/w10050561 - 26 Apr 2018

Cited by 10 | Viewed by 5768

Abstract

This paper presents results from experiments that were carried out to study the effect of porosity and grain orientation on flow resistance. Experiments were performed over three rough surfaces; a water-worked gravel-bed, its non-porous facsimile (cast-bed) and the rotated cast-bed (cast tiles rotated [...] Read more.

This paper presents results from experiments that were carried out to study the effect of porosity and grain orientation on flow resistance. Experiments were performed over three rough surfaces; a water-worked gravel-bed, its non-porous facsimile (cast-bed) and the rotated cast-bed (cast tiles rotated through 180°). The first two beds were used to isolate the influence of gravel-bed porosity on the bulk flow resistance and the rotated cast was used to study effect of the grain orientation on the flow resistance. The results showed that the rotated cast-bed exerted the highest flow resistance whereas the porous water-worked gravel-bed was, for comparable hydraulic boundary conditions, characterized by slightly higher flow resistance than its non-porous counterpart. The results from the bulk flow analysis were substantiated by a preliminary analysis of flow velocity data. Full article

(This article belongs to the Special Issue Turbulence in River and Maritime Hydraulics)

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19 pages, 4189 KiB

Open AccessFeature PaperArticle

Sub-Seasonal Snowpack Trends in the Rocky Mountain National Park Area, Colorado, USA

by Steven R. Fassnacht^1,2,3,4,*

, Niah B.H. Venable^1,2

, Daniel McGrath⁵

and Glenn G. Patterson^5,6

¹ ESS-Watershed Science, Colorado State University, Fort Collins, CO 80523-1476, USA

² Natural Resources Ecology Laboratory, Colorado State University, Fort Collins, CO 80523-1499, USA

³ Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, CO 80523-1375, USA

⁴ Cartography, GIS and Remote Sensing Department, Institute of Geography, Georg-August Universität Göttingen, Goldschmidt Street 5, 37007 Göttingen, Germany

⁵ Department of Geosciences, Colorado State University, Fort Collins, CO 80523-1482, USA

⁶ Public Health, University of Colorado Denver, Aurora, CO 80045, USA

Water 2018, 10(5), 562; https://doi.org/10.3390/w10050562 - 26 Apr 2018

Cited by 28 | Viewed by 8631

Abstract

We present a detailed study of the snowpack trends in the Rocky Mountain National Park (RMNP) using snow telemetry and snow course data at a monthly resolution. We examine the past 35 years (1981 to 2016) to explore monthly patterns over 36 locations [...] Read more.

We present a detailed study of the snowpack trends in the Rocky Mountain National Park (RMNP) using snow telemetry and snow course data at a monthly resolution. We examine the past 35 years (1981 to 2016) to explore monthly patterns over 36 locations and used some additional data to help interpret the changes. The analysis is at a finer spatial and temporal scale than previous studies that focused more on aggregate- or regional-scale changes. The trends in the first of the month’s snow water equivalent (SWE) varied more than the change in the monthly SWE, monthly precipitation or mean temperature. There was greater variability in SWE trends on the west side of the study area, and on average the declines in the west were greater. At higher elevations, there was more of a decline in the SWE. Changes in the climate were much less in winter than in summer. Per decade, the average decline in the winter precipitation was 4 mm and temperatures warmed by 0.29 °C, while the summer precipitation declined by 9 mm and temperatures rose by 0.66 °C. In general, November and March became warmer and drier, yielding a decline of the SWE on December 1^st and April 1^st, while December through February and May became wetter. February and May became cooler. Full article

(This article belongs to the Special Issue Effects of Climate Change on the Hydrology and Water Quality of Snow-Dominated Mountainous Environments)

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12 pages, 2188 KiB

Open AccessArticle

Spatio-Temporal Variations of the Stable H-O Isotopes and Characterization of Mixing Processes between the Mainstream and Tributary of the Three Gorges Reservoir

by Rong Jiang¹, Yufei Bao^2,3,*, Yong Shui⁴, Yuchun Wang^2,3,*

, Mingming Hu^2,3, Yao Cheng^2,5

, Aiming Cai³, Pengcheng Du³ and Zhenya Ye³

¹ Key Laboratory of Three Gorges Reservoir Region’s Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China

² State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China

³ Department Key Laboratory of Water Environment, China Institute of Water Resources and Hydropower Research, Beijing 100038, China

⁴ The Tibet Autonomous Region Hydrology and Water Resources Survey, Tibet Autonomous Region 850000, China

⁵ College of Water Conservancy and Hydropower, Hebei University of Engineering, Handan 056001, China

Water 2018, 10(5), 563; https://doi.org/10.3390/w10050563 - 26 Apr 2018

Cited by 18 | Viewed by 4016

Abstract

Understanding the runoff characteristics and interaction processes between the mainstream and its tributaries are an essential issue in watershed and water management. In this paper, hydrogen (δD) and oxygen (δ¹⁸O) isotope techniques were used in the mainstream and Zhuyi Bay (ZYB) [...] Read more.

Understanding the runoff characteristics and interaction processes between the mainstream and its tributaries are an essential issue in watershed and water management. In this paper, hydrogen (δD) and oxygen (δ¹⁸O) isotope techniques were used in the mainstream and Zhuyi Bay (ZYB) of the Three Gorges Reservoir (TGR) during the wet and dry seasons in 2015. It revealed that (1) Precipitation was the main source of stream flow compared to the TGR water line with meteoric water line of the Yangtse River basin; (2) The δD and δ¹⁸O values exhibited a ‘toward lighter-heavier’ trend along mainstream due to the continuous evaporation effect in the runoff direction, and the fluctuations reflected incoming water from the nearest tributaries. The general trend of d-excess increased with increasing distance from the Three Gorges Dam, which indicated that kinetic fractionation was an important process affecting the isotopic composition. The enrichment effect of isotopes was found in the downstream of TGR; (3) Water mass from the TGR mainstream flowed backward to the confluence zone of ZYB via the middle and bottom layers in the dry season, whereas in the wet season, water reversed through the upper-middle layers due to thermal density flows. This study described and demonstrated that the water cycle of TGR was driven by natural environmental variability and operational system, which will provide valuable information for the water resource management and for controlling the algal blooms in the future. Full article

(This article belongs to the Section Water Resources Management, Policy and Governance)

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25 pages, 12262 KiB

Open AccessArticle

Assessing Long-Term Hydrological Impact of Climate Change Using an Ensemble Approach and Comparison with Global Gridded Model-A Case Study on Goodwater Creek Experimental Watershed

by Sagar Gautam^1,*, Christine Costello²

, Claire Baffaut³, Allen Thompson¹, Bohumil M. Svoma⁴, Quang A. Phung¹

and Edward J. Sadler³

¹ Department of Bioengineering, University of Missouri, Columbia, MO 65201, USA

² Industrial & Manufacturing Systems Engineering, University of Missouri, Columbia, MO 65201, USA

³ USDA–ARS, Cropping Systems and Water Quality Research Unit, Columbia, MO 65211, USA

⁴ Salt River Project, Surface Water Resources, Tempe, AZ 85072, USA

Water 2018, 10(5), 564; https://doi.org/10.3390/w10050564 - 26 Apr 2018

Cited by 20 | Viewed by 9011

Abstract

Potential impacts of climate change on the hydrological components of the Goodwater Creek Experimental Watershed were assessed using climate datasets from the Coupled Model Intercomparison Project Phase 5 and Soil and Water Assessment Tool (SWAT). Historical and future ensembles of downscaled precipitation and [...] Read more.

Potential impacts of climate change on the hydrological components of the Goodwater Creek Experimental Watershed were assessed using climate datasets from the Coupled Model Intercomparison Project Phase 5 and Soil and Water Assessment Tool (SWAT). Historical and future ensembles of downscaled precipitation and temperature, and modeled water yield, surface runoff, and evapotranspiration, were compared. Ensemble SWAT results indicate increased springtime precipitation, water yield, surface runoff and a shift in evapotranspiration peak one month earlier in the future. To evaluate the performance of model spatial resolution, gridded surface runoff estimated by Lund–Potsdam–Jena managed Land (LPJmL) and Jena Diversity-Dynamic Global Vegetation model (JeDi-DGVM) were compared to SWAT. Long-term comparison shows a 6–8% higher average annual runoff prediction for LPJmL, and a 5–30% lower prediction for JeDi-DGVM, compared to SWAT. Although annual runoff showed little change for LPJmL, monthly runoff projection under-predicted peak runoff and over-predicted low runoff for LPJmL compared to SWAT. The reasons for these differences include differences in spatial resolution of model inputs and mathematical representation of the physical processes. Results indicate benefits of impact assessments at local scales with heterogeneous sets of parameters to adequately represent extreme conditions that are muted in global gridded model studies by spatial averaging over large study domains. Full article

(This article belongs to the Special Issue Hydrological Modelling and Remote Sensing: Selected Papers from the 2017 and 2018 SWAT International Conferences)

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21 pages, 4644 KiB

Open AccessArticle

An Optimization Model for Water Management Based on Water Resources and Environmental Carrying Capacities: A Case Study of the Yinma River Basin, Northeast China

by Chong Meng, Xiaolei Wang and Yu Li^*

College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China

Water 2018, 10(5), 565; https://doi.org/10.3390/w10050565 - 26 Apr 2018

Cited by 50 | Viewed by 5245

Abstract

In this study, an inexact two-stage stochastic programming (ITSP) model was developed for supporting water resources allocation for the four main water use sectors (industry, municipal, environmental, and agriculture) and total amount control of the pollutant emissions. The Yinma River Basin in northeast [...] Read more.

In this study, an inexact two-stage stochastic programming (ITSP) model was developed for supporting water resources allocation for the four main water use sectors (industry, municipal, environmental, and agriculture) and total amount control of the pollutant emissions. The Yinma River Basin in northeast China was selected for a case study. A number of scenarios corresponding to different flow levels were examined. The flow levels reflect different probabilities of water resource availability and environmental carrying capacity. The results revealed that the optimal allocation strategies for each sector depend on water resource carrying capacity, wastewater treatment capacity, the total amount of regional control, and the water environment carrying capacity. Water ecology projects were identified that are needed to treat contaminated water and to address the insufficient carrying capacity for pollutant emissions generated in water-using processes. The results will be helpful for establishing sensible water management systems that integrate the development and utilization of water resources and protect the environment, and for providing a basis for water pollution prevention plans, the model can be used to guide management interventions to improve the water environment by regional pollutant emission control and the improvement of carrying capacity in the Yinma River Basin. Full article

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16 pages, 3259 KiB

Open AccessArticle

Analysis of the Precipitation Regime over the Ligurian Sea

by Sara Pensieri^1,*

, Maria Elisabetta Schiano¹, Paola Picco², Marco Tizzi³

and Roberto Bozzano¹

¹ National Research Council of Italy, via De Marini 6, 16149 Genoa, Italy

² Istituto Idrografico della Marina, Passo dell’Osservatorio 4, 16134 Genoa, Italy

³ Regional Environmental Protection Agency of Liguria, viale Brigate Partigiane 2, 16129 Genoa, Italy

Water 2018, 10(5), 566; https://doi.org/10.3390/w10050566 - 27 Apr 2018

Cited by 11 | Viewed by 5070

Abstract

The regions surrounding the North West Mediterranean Sea are often sites of intense precipitation events, particularly during the autumn months. The many casualties and the high economic costs due to these events demand a continuous improvement in forecasting models in support of early [...] Read more.

The regions surrounding the North West Mediterranean Sea are often sites of intense precipitation events, particularly during the autumn months. The many casualties and the high economic costs due to these events demand a continuous improvement in forecasting models in support of early warning systems. The main weather conditions that determine episodes of heavy rain over these regions are known, but the high number of processes and interactions taking place at different time and space scales makes it extremely difficult to increase the skill pertaining to their predictability. To deepen the knowledge of the phenomena, both numerical simulations and analysis of historical data sets are required. This paper presents the analysis of a five-year-long time series of rain data collected in the open Ligurian Sea from the fixed platform W1M3A and coastal stations. The analysis aims to characterize the main features of the precipitation over this area and its seasonal and annual variability. Furthermore, the work includes a description of the main atmospheric and oceanic surface parameters measured from the platform during some intense events that occurred in the period 2009–2013 and suggests to what extent offshore observations may contribute to improve the forecast of rainfall events. Full article

(This article belongs to the Special Issue Impact of Climate on Hydrological Extremes)

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12 pages, 2051 KiB

Open AccessArticle

Translocation of Soil Particles during Secondary Soil Tillage along Contour Lines

by Novák Petr^* and Hůla Josef

Faculty of Engineering, Czech University of Life Sciences Prague, Kamýcká 129, 165 21 Prague 6, Suchdol, Czech Republic

Water 2018, 10(5), 568; https://doi.org/10.3390/w10050568 - 27 Apr 2018

Cited by 5 | Viewed by 4044

Abstract

A high percentage of arable land and erosion risk on agricultural land are typical of current agriculture. While tillage erosion is a less frequently studied issue, it impacts vast areas of agricultural land. Not all relationships between cultivation equipment, the gradient of the [...] Read more.

A high percentage of arable land and erosion risk on agricultural land are typical of current agriculture. While tillage erosion is a less frequently studied issue, it impacts vast areas of agricultural land. Not all relationships between cultivation equipment, the gradient of the plot and other factors have been known until now. Intensive soil tillage can be a crucial erosive factor mainly when the cultivation equipment moves in a fall line direction. Nevertheless, even when the equipment moves along contour lines, soil particles can be translocated perpendicular to the direction of the equipment movement (in a fall line direction). This phenomenon has not yet been adequately studied. For measurements, a field trial with secondary tillage of soil was laid out (a seedbed preparation implement was used). The objective of the trial was to evaluate the effect of the working tools of the cultivation equipment on the crosswise and lengthwise translocation of soil particles during soil tillage. Aluminium cubes, with a side length of 16 mm, were used as tracers. Before the operation, the tracers were inserted in a row perpendicular (at a right angle) to a direction of the equipment passes. After the equipment passes, position of tracers was evaluated within a two-axis grid. The trial was performed at three gradients of the plot (2°, 6° and 11°). For each gradient, the 1-pass, 2-pass and 3-pass treatments were tested. The equipment always moved along the plot contour line. After the equipment passes in all treatments, all tracers were localized on an orthogonal grid. The results of the trial demonstrate the effect of the slope gradient on the crosswise translocation of particles during secondary tillage of soil in the slope direction. The tillage equipment translocated particles in the fall line direction even if it passed along the contour line. With the increasing intensity of passes, the effect of the equipment on crosswise translocation increases. During secondary tillage of soil, the working tools of the equipment have an erosive effect (causing tillage erosion), even though the equipment moves along the contour line. Full article

(This article belongs to the Special Issue Soil Water Conservation: Dynamics and Impact)

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19 pages, 9020 KiB

Open AccessArticle

Lagoon Sediment Dynamics: A Coupled Model to Study a Medium-Term Silting of Tidal Channels

by Marco Petti, Silvia Bosa

and Sara Pascolo^*

Dipartimento Politecnico di Ingegneria e Architettura, University of Udine, 33100 Udine, Italy

Water 2018, 10(5), 569; https://doi.org/10.3390/w10050569 - 27 Apr 2018

Cited by 36 | Viewed by 5295

Abstract

The silting of tidal channels is a natural process that affects several shallow lagoons and makes it difficult to navigate, requiring regular maintenance interventions. This phenomenon is the result of the complex non-linear interaction between tidal currents and wave motion. In this work, [...] Read more.

The silting of tidal channels is a natural process that affects several shallow lagoons and makes it difficult to navigate, requiring regular maintenance interventions. This phenomenon is the result of the complex non-linear interaction between tidal currents and wave motion. In this work, the morphodynamic evolution of the Marano and Grado lagoon is investigated by means of a two-dimensional horizontal (2DH) morphological-hydrodynamic and a spectral coupled model. An innovative procedure to reproduce the overall bathymetric changes in the medium term and, in particular, the volumes deposited inside channels, is presented. An average year with a sequence of winds and tides acting over that time was reconstructed, carrying out cross correlation techniques and spectral analyses of measured data. The predicted morphological evolution matches the annual dredged volumes in the lagoon critical branches and shows the distribution of erosion and deposition of cohesive sediments according to spatially variable values of critical shear stress. Full article

(This article belongs to the Section Hydraulics and Hydrodynamics)

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10 pages, 2773 KiB

Open AccessArticle

Groundwater Abstraction through Siphon Wells—Hydraulic Design and Energy Savings

by Rico Bartak and Thomas Grischek^*

Faculty of Civil Engineering & Architecture, Dresden University of Applied Sciences, 01069 Dresden, Germany

Water 2018, 10(5), 570; https://doi.org/10.3390/w10050570 - 27 Apr 2018

Cited by 4 | Viewed by 9292

Abstract

Siphon pipes were used for groundwater abstraction from wells before the development of submersible pumps. Many of the existing and operational systems were built before the 1950s and require rehabilitation. Siphon wells are difficult to design and, therefore, are often equipped with submersible [...] Read more.

Siphon pipes were used for groundwater abstraction from wells before the development of submersible pumps. Many of the existing and operational systems were built before the 1950s and require rehabilitation. Siphon wells are difficult to design and, therefore, are often equipped with submersible pumps when the system is rehabilitated or renewed. This study presents a novel calculation tool for siphon wells and investigates the energy savings of such system in comparison to an alternative equipment with submersible pumps. A theoretical energy savings of 38% was first estimated compared to individually-operated wells (IOW) for a fictional design example just based on the calculated water levels and abstraction rates. Real energy data from two riverbank filtration (RBF) sites, which operate both siphon and IOW, were investigated in the second part of the study. The analysis of measured data revealed energy savings of 36–69%, confirming the theoretical estimation. Full article

(This article belongs to the Special Issue Energy Efficient Management of Water Collection, Treatment, Storage and Distribution)

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17 pages, 3225 KiB

Open AccessFeature PaperArticle

Quantitative Evaluation of the Impact of Climate Change and Human Activity on Runoff Change in the Dongjiang River Basin, China

by Yuliang Zhou¹

, Chengguang Lai^2,*

, Zhaoli Wang², Xiaohong Chen³

, Zhaoyang Zeng², Jiachao Chen² and Xiaoyan Bai⁴

¹ School of Civil Engineering, Hefei University of Technology, Hefei 230009, China

² School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510641, China

³ Center for Water Resource and Environment, Sun Yat-Sen University, Guangzhou 510275, China

⁴ Department of Environmental Engineering, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China

Water 2018, 10(5), 571; https://doi.org/10.3390/w10050571 - 27 Apr 2018

Cited by 50 | Viewed by 6685

Abstract

Climate change and human activity are typically regarded as the two most important factors affecting runoff. Quantitative evaluation of the impact of climate change and human activity on runoff is important for the protection, planning, and management of water resources. This study assesses [...] Read more.

Climate change and human activity are typically regarded as the two most important factors affecting runoff. Quantitative evaluation of the impact of climate change and human activity on runoff is important for the protection, planning, and management of water resources. This study assesses the contributions of climate change and human activity to runoff change in the Dongjiang River basin from 1960 to 2005 by using linear regression, the Soil and Water Assessment Tool (SWAT) hydrologic model, and the climate elasticity method. Results indicate that the annual temperature in the basin significantly increased, whereas the pan evaporation in the basin significantly decreased (95%). The natural period ranged from 1960 to 1990, and the affected period ranged from 1991 to 2005. The percentage of urban area during the natural period, which was 1.94, increased to 4.79 during the affected period. SWAT modeling of the Dongjiang River basin exhibited a reasonable and reliable performance. The impacts induced by human activity on runoff change were as follows: 39% in the upstream area, 13% in the midstream area, 77% in the downstream area, and 42% in the entire basin. The impacts of human activity on runoff change were greater in the downstream area than in either upstream and midstream areas. However, the contribution of climate change (58%) is slightly larger than that of human activity (42%) in the whole basin. Full article

(This article belongs to the Special Issue Water Quality: A Component of the Water-Energy-Food Nexus)

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41 pages, 67163 KiB

Open AccessArticle

Numerical Modeling of Long-Term Biogeochemical Processes and Its Application to Sedimentary Bed Formation in Tokyo Bay

by Mangala Amunugama^* and Jun Sasaki

Department of Socio-Cultural Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8563, Japan

Water 2018, 10(5), 572; https://doi.org/10.3390/w10050572 - 27 Apr 2018

Cited by 4 | Viewed by 4617

Abstract

Even though models of water quality have become increasingly detailed over time, their applicability to analyze long-term effect on sedimentary bed formation is yet to be clarified. Hence, an integrated, layer-resolved, process-based, sediment–water coupled, long-term robust, three-dimensional (3D) ecosystem model, including realistic sedimentary [...] Read more.

Even though models of water quality have become increasingly detailed over time, their applicability to analyze long-term effect on sedimentary bed formation is yet to be clarified. Hence, an integrated, layer-resolved, process-based, sediment–water coupled, long-term robust, three-dimensional (3D) ecosystem model, including realistic sedimentary and pelagic processes, was developed. The constituents of the integrated model included a multi layered ecosystem model, a quasi-three dimensional hydrodynamic model, a wave hindcasting model, and a sediment deposition and erosion model. Because numerical modeling difficulties arise in setting the initial conditions, especially for a sedimentary bed, this novel modeling approach suggests to initiate the model with the simplest initial conditions of no particulate organic carbon content (POCC) and uniform inorganic sediment distribution. The model was applied to Tokyo Bay and quasi-steady state POCC in the sediment was obtained through long-term computation with realistic sedimentary and pelagic processes. Wave induced bed shear stress (WBSS) is critical for sediment erosion and spatial movement of sediment pollution, while a stable morphology is determined by the balance between the current induced bed shear stress (CBSS) and WBSS in Tokyo Bay. This novel modeling approach, with the simplest sedimentary initial conditions and realistic sedimentary and pelagic processes, provides a great tool for long-term ecosystem modeling in future studies. Full article

(This article belongs to the Section Water Quality and Contamination)

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10 pages, 1246 KiB

Open AccessArticle

Assessment of a Field Tidal Flow Constructed Wetland in Treatment of Swine Wastewater: Life Cycle Approach

by Tong Wang¹, Ranbin Liu²

, Kate O’Meara², Emmet Mullan² and Yaqian Zhao^2,3,*

¹ School of Civil Engineering, Chang’an University, Xian 710061, China

² UCD Dooge Centre for Water Resources Research, School of Civil Engineering, University College Dublin, Newstead, Belfield, Dublin D04 K3H4, Ireland

³ Key Laboratory of Subsurface Hydrology and Ecology in Arid Areas (Ministry of Education), School of Environmental Science and Engineering, Chang’an University, Xian 710054, China

Water 2018, 10(5), 573; https://doi.org/10.3390/w10050573 - 28 Apr 2018

Cited by 17 | Viewed by 6009

Abstract

The spreading of livestock wastewater onto the grassland poses the inevitable risk of pollutants into the surface water or ground water, causing adverse environmental problems. Although the constructed wetlands (CWs) represent a cost-effective treatment system, they fail to achieve satisfactory total nitrogen (TN) [...] Read more.

The spreading of livestock wastewater onto the grassland poses the inevitable risk of pollutants into the surface water or ground water, causing adverse environmental problems. Although the constructed wetlands (CWs) represent a cost-effective treatment system, they fail to achieve satisfactory total nitrogen (TN) removal performance. Dewatered alum sludge (DAS) based CW with tidal flow operation strategy is set up to intensify the TN removal efficiency by creating alternating aerobic and anoxic conditions, which relies on the water pumps instead of air pumps. In the present study, the environmental performance of a four-stage field tidal flow CW system treating swine wastewater was evaluated based on the life cycle assessment (LCA). The contribution of each process in LCA was clarified and compared whereby the potential improvement was indicated for further application. The results showed that the electricity almost dominated all the environmental impact categories while the water pumps (used for creating tidal flow) were the dominant electricity consumer. Moreover, the mitigation effect of vegetation by uptaking CO₂ was relatively marginal. Overall, compared with conventional CWs, the tidal flow CW brought about more adverse impact to the environment although the tidal flow could achieve better treatment efficiency. Full article

(This article belongs to the Special Issue Wetlands for the Treatment of Agricultural Drainage Water)

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11 pages, 1308 KiB

Open AccessArticle

The Effect of Bioaugmentation with Archaea on the Oxygen Uptake Rate in a Sequencing Batch Reactor

by Aleksandra Szaja¹, Grzegorz Łagód¹

, Katarzyna Jaromin-Gleń^2,* and Agnieszka Montusiewicz¹

¹ Faculty of Environmental Engineering, Lublin University of Technology, Nadbystrzycka Str. 40B, 20-618 Lublin, Poland

² Institute of Agrophysics, Polish Academy of Sciences, Doswiadczalna 4 Str., 20-290 Lublin, Poland

Water 2018, 10(5), 575; https://doi.org/10.3390/w10050575 - 28 Apr 2018

Cited by 7 | Viewed by 4157

Abstract

The aim of this study was to evaluate the effect of bioaugmentation with Archaea domain organisms on the activated sludge (AS) expressed by the oxygen uptake rate (OUR) in a laboratory sequencing batch reactor (SBR). The influence of depletion of the external substrate [...] Read more.

The aim of this study was to evaluate the effect of bioaugmentation with Archaea domain organisms on the activated sludge (AS) expressed by the oxygen uptake rate (OUR) in a laboratory sequencing batch reactor (SBR). The influence of depletion of the external substrate in bioaugmented (SBR-A) and non-bioaugmented (SBR-B) activated sludge during aerobic stabilization was investigated. The experiment was divided into two steps. First, the OUR was measured in the standard conditions of biological treatment. Second, AS was only aerated in the absence of the substrate. It was observed that bioaugmentation with Archaea had an increasing effect on the endogenous and exogenous OUR of the sludge in both phases. In the first phase, the average endogenous OUR was 28.70 ± 2.75 and 21.63 ± 0.9 mgO₂·dm⁻³·h⁻¹ in the SBR-A and SBR-B, respectively. Regarding the exogenous OUR, the average values were 95.55 ± 11.33 and 57.15 ± 24.56 mgO₂·dm⁻³·h⁻¹ for the SBR-A and SBR-B, respectively. Archaea enhancing its biological activity, expressed as the OUR, exert a stabilizing effect on this parameter of AS and ensure its lower sensitivity to changes in the process conditions, substrate supply disruption and prolonged aeration. Full article

(This article belongs to the Section Wastewater Treatment and Reuse)

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13 pages, 1778 KiB

Open AccessArticle

Draining Effects on Recent Accumulation Rates of C and N in Zoige Alpine Peatland in the Tibetan Plateau

by Chunyi Li^1,2, Yilan Huang^1,2, Huanhuan Guo³, Lijuan Cui^1,2,* and Wei Li^1,2

¹ Beijing Key Laboratory of Wetland Services and Restoration, Institute of Wetland Research, Chinese Academy of Forestry, Beijing 100091, China

² Sichuan Zoige Wetland Ecosystem Research Station, Tibetan Autonomous Prefecture of Aba 624500, China

³ College of Forestry, Beijing Forestry University, Beijing 100083, China

Water 2018, 10(5), 576; https://doi.org/10.3390/w10050576 - 28 Apr 2018

Cited by 3 | Viewed by 4524

Abstract

Peatlands play an essential role in the global carbon (C) and nitrogen (N) cycling. In order to ascertain the draining effects on recent accumulation rates of C (RERCA) and N (RERNA) in the Zoige peatland in the eastern Qinghai-Tibet Plateau, the core samples [...] Read more.

Peatlands play an essential role in the global carbon (C) and nitrogen (N) cycling. In order to ascertain the draining effects on recent accumulation rates of C (RERCA) and N (RERNA) in the Zoige peatland in the eastern Qinghai-Tibet Plateau, the core samples of peat growth, C and N accumulation for both natural and drained peatlands were measured using ²¹⁰Pb and ¹³⁷Cs dating methods. As a result, RERCA and RERNA showed an increasing trend from the bottom to the surface of the peatland, which was in accordance with the peat accumulation rates. However, the average RERCA in permanently flooded and seasonally flooded peatlands were 1.5–2.5 times that of drainage peatlands, and the average of RERNA were 1.2–1.7 times. Our findings indicate that the Zoige peatland is still in the stage of peat development with a large carbon sequestration capacity, and drainage from human activities leads to the decreasing of RERCA and RERNA, which will contribute to the selection of the effective ways to slow down the anthropogenic effects on the degradation of the Zoige peatland. Full article

(This article belongs to the Special Issue Soil-Plant-Water Relationships )

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14 pages, 1890 KiB

Open AccessArticle

Top-Down and Bottom-Up Approaches for Water-Energy Balance in Portuguese Supply Systems

by Aisha Mamade^1,2,*, Dália Loureiro², Helena Alegre²

and Dídia Covas¹

¹ Civil Engineering Research and Innovation for Sustainability (CERIS), Instituto Superior Técnico, Universidade de Lisboa, Lisbon 1049-001, Portugal

² Hydraulics Department, National Civil Engineering Laboratory, Lisbon 1700-066, Portugal

Water 2018, 10(5), 577; https://doi.org/10.3390/w10050577 - 28 Apr 2018

Cited by 27 | Viewed by 6920

Abstract

Water losses are responsible for increased energy consumption in water supply systems (WSS). The energy associated with water losses (EWL) is typically considered to be proportional to the water loss percentage obtained in water balances. However, this hypothesis is yet to be proved [...] Read more.

Water losses are responsible for increased energy consumption in water supply systems (WSS). The energy associated with water losses (EWL) is typically considered to be proportional to the water loss percentage obtained in water balances. However, this hypothesis is yet to be proved since flow does not vary linearly with headlosses in WSS. The aim of this paper is to validate the hypothesis, present real-life values for water-energy balance (WEB) components, and reference values for the key performance indicator that represents the ratio of total energy in excess (E3). This validation is achieved through the application of two approaches—top-down and bottom-up. The first approach requires minimum data, gives an overview of the main WEB components, and provides an effective diagnosis of energy inefficiencies through the calculation of E3 related to pumps, water losses, and networks. The second approach requires calibrated hydraulic models and provides a detailed assessment of the WEB components. Results allow the validation of the stated hypothesis as well as show that the most significant energy inefficiencies are associated with surplus energy, pumping, and water losses, each reaching up to 40% of total input energy. Less significant components are pipe friction and valve headlosses, each reaching up to 15% of total input energy. Full article

(This article belongs to the Special Issue Energy Efficient Management of Water Collection, Treatment, Storage and Distribution)

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11 pages, 3523 KiB

Open AccessArticle

Modified Septic Tank: Innovative Onsite Wastewater Treatment System

by Bassim E. Abbassi^1,*

, Raihan Abuharb²

, Bashaar Ammary²

, Naser Almanaseer²

and Christopher Kinsley³

¹ School of Engineering, University of Guelph, Guelph, ON N1G2W1, Canada

² Department of Water Resources and Environmental Management, Al-Balqa Applied University, 19117 Al-Salt, Jordan

³ Civil Engineering Department, University of Ottawa, Ottawa, ON K1N 6N5, Canada

Water 2018, 10(5), 578; https://doi.org/10.3390/w10050578 - 29 Apr 2018

Cited by 28 | Viewed by 12863

Abstract

This research documents two innovative designs of septic tanks used for onsite wastewater treatment. The designs were implemented and tested as part of a research project focused on innovative decentralized wastewater treatment solutions. The modified septic tanks were tested at different hydraulic loading [...] Read more.

This research documents two innovative designs of septic tanks used for onsite wastewater treatment. The designs were implemented and tested as part of a research project focused on innovative decentralized wastewater treatment solutions. The modified septic tanks were tested at different hydraulic loading rates for sufficient periods to effectively evaluate their performance. The two systems were designed with successive anaerobic and aerobic chambers and were differentiated between attached and suspended growth. The systems were operated at detention times of 4.3, 3.2, and 2.6 days. High removal of organic load was achieved under all loading criteria in both systems. Effluent BOD₅ concentration at lower and higher loading rates were found to be less than 15 and 25 mg/L, respectively, representing a removal rate of more than 95%. Nitrogen was also removed but at a lower rate. The highest TN removal was achieved (59%) in the attached growth system at the lowest loading rate. Although two logs of E. coli removal (99%) were achieved in all systems, E. coli numbers were high enough to necessitate further tertiary treatment. The modified septic tanks proved to be a cost-effective technology with low energy and O&M requirements. Full article

(This article belongs to the Section Wastewater Treatment and Reuse)

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27 pages, 1046 KiB

Open AccessArticle

Towards Development of an Optimization Model to Identify Contamination Source in a Water Distribution Network

by Oluwaseye Samson Adedoja^1,*

, Yskandar Hamam^1,2

, Baset Khalaf¹ and Rotimi Sadiku³

¹ Department of Electrical Engineering/French South African Institute of Technology (F’SATI), Tshwane University of Technology, Pretoria 0001, South Africa

² École Supérieure d’Ingénieurs en Électrotechnique et Électronique, Cité Descartes, 2 Boulevard Blaise Pascal, 93160 Noisy-le-Grand, Paris, France

³ Department of Chemical Engineering, Tshwane University of Technology, Pretoria 0001, South Africa

Water 2018, 10(5), 579; https://doi.org/10.3390/w10050579 - 29 Apr 2018

Cited by 45 | Viewed by 6631

Abstract

Protection of the water system is paramount due to the negative consequences of contaminated water on the public health. Water resources are one of the critical infrastructures that must be preserved from deliberate and accidental attacks. Water qualities are examined at the treatment [...] Read more.

Protection of the water system is paramount due to the negative consequences of contaminated water on the public health. Water resources are one of the critical infrastructures that must be preserved from deliberate and accidental attacks. Water qualities are examined at the treatment plant. However, its quality can substantially be contaminated during transportation from the plant to the consumers’ taps. Contamination in water distribution networks (WDNs) is a danger that can have severe consequences on public health as well as an economic and social instability. Water distribution networks are immensely susceptible to deliberate or accidental attacks due to the complex nature of the system. Hence, contamination source identification (CSI) is a topical issue in water distribution systems that require immediate attention of researchers in order to protect mankind from the adverse effect of consuming contaminated water. Usually, a contaminant event can be detected by the water quality monitoring sensors or the contaminant warning system (CWS) installed on the network. Nevertheless, how to derive the source of the contamination from the collected information is a difficult task that must be tackled in order to evaluate the spread of the contamination and for immediate remedial strategies. In the past two decades, considerable efforts and advancement have been made by researchers applying various techniques in order to locate the source of the contamination in WDNs. Each of the techniques has certain limitations and applicability as reported in the literature. This paper presents a comprehensive review of the existing techniques with emphasis on their importance and technical challenges. Despite a series of investigations in this domain, the field is yet to be unified. Hence, open research areas are still available to explore. Consequently, improvement on the existing techniques is necessary and hereby suggested. More importantly, practical application of these techniques offer a major research gap that must be addressed. Full article

(This article belongs to the Special Issue Water Networks Management: New Perspectives)

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19 pages, 2994 KiB

Open AccessArticle

Effect of Environmental Conditions and Morphometric Parameters on Surface Water Temperature in Polish Lakes

by Mariusz Ptak^1,*

, Mariusz Sojka², Adam Choiński¹ and Bogumił Nowak³

¹ Department of Hydrology and Water Management, Adam Mickiewicz University, Krygowskiego 10, 61-680 Poznań, Poland

² Institute of Land Improvement, Environmental Development and Geodesy, Poznań University of Life Sciences, Piątkowska 94, 60-649 Poznań, Poland

³ Institute of Meteorology and Water Management, National Research Institute, Podleśna 61, 01-673 Warszawa, Poland

Water 2018, 10(5), 580; https://doi.org/10.3390/w10050580 - 29 Apr 2018

Cited by 74 | Viewed by 6640

Abstract

The study evaluated the effect of environmental conditions and morphometric parameters on lake water temperature changes. The analysis was carried out on the basis of 14 lakes located in northern Poland. The assessment was based on the daily water and air temperatures from [...] Read more.

The study evaluated the effect of environmental conditions and morphometric parameters on lake water temperature changes. The analysis was carried out on the basis of 14 lakes located in northern Poland. The assessment was based on the daily water and air temperatures from 1972 to 2016. It took into account the location of lakes (latitude, longitude, altitude) morphometric parameters (surface area, maximum and mean depth, volume), hydrological processes (rate of water exchange, course of ice phenomena), and trophic status (water transparency) as factors that can modify lake water temperature changes. Direction and rate of air and water temperature changes were analysed by means of Mann–Kendall’s and Sen’s tests. Cluster analysis (CA) was applied to group lakes characterised by similar water temperature changes. The effect of climatic and non-climatic parameters on a lake’s water temperature was assessed on the basis of principal component analysis (PCA). Water temperatures in the lakes in the years 1972–2016 were characterised by a higher rate of increase of 0.43 °C·dec⁻¹ than the air temperature decrease of 0.34 °C·dec⁻¹. The analysis showed a faster rate of heating of waters in western Poland. This can be explained by shorter duration of ice cover. Moreover, the changes of water temperature were affected by other factors, including the location of the lakes, their morphometric parameters, wind speed, water transparency and water exchange time. Full article

(This article belongs to the Section Hydrology)

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21 pages, 1557 KiB

Open AccessArticle

Sustainability Evaluation Framework of Urban Stormwater Drainage Options for Arid Environments Using Hydraulic Modeling and Multicriteria Decision-Making

by Mohammad Alhumaid¹, Abul Razzaq Ghumman^2,*

, Husnain Haider²

, Ibrahim Saleh Al-Salamah² and Yousry Mahmoud Ghazaw^2,3

¹ Municipality of Buraydah, Buraydah, 51431 Al Qassim, Saudi Arabia

² Department of Civil Engineering, College of Engineering, Qassim University, Buraydah, 51431 Al Qassim, Saudi Arabia

³ Department of Irrigation and Hydraulics, College of Engineering, Alexandria University, Alexandria 21544, Egypt

Water 2018, 10(5), 581; https://doi.org/10.3390/w10050581 - 29 Apr 2018

Cited by 27 | Viewed by 7086

Abstract

Stormwater drainage systems in urban areas located in arid environmental regions generally consist of storm-sewer networks and man-made ponds for the collection and disposal of runoff, respectively. Due to expansion in cities’ boundaries as a result of population growth, the capacity of existing [...] Read more.

Stormwater drainage systems in urban areas located in arid environmental regions generally consist of storm-sewer networks and man-made ponds for the collection and disposal of runoff, respectively. Due to expansion in cities’ boundaries as a result of population growth, the capacity of existing drainage systems has been exhausted. Therefore, such systems overflow even during the smaller (than the design) return period floods. At the same time, changing rainfall patterns and flash floods due to climate change are other phenomena that need appropriate attention. Consequently, the municipalities in arid environmental regions are facing challenges for effective decision-making concerning (i) improvement needs for drainage networks for safe collection of stormwater, (ii) selection of most feasible locations for additional ponds, and (iii) evaluation of other suitable options, such as micro-tunneling. In this research, a framework has been developed to evaluate different stormwater drainage options for urban areas of arid regions. Rainfall-runoff modeling was performed with the help of Hydrological-Engineering-Centre, Hydrological-Modelling-System (HEC-HMS). To evaluate the efficacy of each option for handling a given design flood, hydraulic-modeling was performed using SewerGEMS. Meteorological and topographical data was gathered from the Municipality of Buraydah and processed to generate different inputs required for hydraulic modeling. Finally, multicriteria decision-making (MCDM) was performed to evaluate all the options on the basis of four sustainability criteria, i.e., flood risk, economic viability, environmental impacts, and technical constraints. Criteria weights were established through group decision-making using the Analytic Hierarchy Process (AHP). Preference-Ranking-Organization-Method for Enrichment-Evaluation (PROMETHEE II) was used for final ranking of stormwater drainage options. The proposed framework has been implemented on a case of Buraydah City, Qassim, Saudi Arabia, to evaluate its pragmatism. Micro-tunnelling was found to be the most sustainable option. Full article

(This article belongs to the Section Urban Water Management)

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15 pages, 3445 KiB

Open AccessArticle

Influence of an Extended Domestic Drinking Water System on the Drinking Water Quality

by Ljiljana Zlatanović^1,2,*, Aleksandra Knezev³, Jan Peter Van der Hoek^1,2,4

and Jan H. G. Vreeburg⁵

¹ Department of Water Management, Delft University of Technology, 2628 CN Delft, The Netherlands

² Amsterdam Institute for Advanced Metropolitan Solutions, 1092 AD Amsterdam, The Netherlands

³ Het Waterlaboratorium, 2031 BE Haarlem, The Netherlands

⁴ Waternet, Strategic Centre, 1096 AC Amsterdam, The Netherlands

⁵ Evides Water Company, 3063 NH Rotterdam, The Netherlands

Water 2018, 10(5), 582; https://doi.org/10.3390/w10050582 - 30 Apr 2018

Cited by 5 | Viewed by 5957

Abstract

Drinking water and fire safety are strongly bonded to each other. Actual drinking water demand and fire flows are both delivered through the same network, and are both devoted to public health and safety. In The Netherlands, the discussion about fire flows supplied [...] Read more.

Drinking water and fire safety are strongly bonded to each other. Actual drinking water demand and fire flows are both delivered through the same network, and are both devoted to public health and safety. In The Netherlands, the discussion about fire flows supplied by the drinking water networks has drawn fire fighters and drinking water companies together, searching for novel approaches to improve public safety. One of these approaches is the application of residential fire sprinkler systems fed by drinking water. This approach has an impact on the layout of domestic drinking water systems (DDWSs), as extra plumbing is required. This study examined the influence of the added plumbing on quality of both fresh and 10 h stagnant water in two full scale DDWSs: a conventional and an extended system. Overnight stagnation was found to promote copper and zinc leaching from pipes in both DDWSs. Microbial numbers and viability in the stagnant water, measured by heterotrophic plate count (HPC), flow cytometry (FCM) and adenosine tri-phosphate (ATP), depended on the temperature of fresh water, as increased microbial numbers and viability was measured in both DDWSs when the temperature of fresh water was below the observed tipping point (15 °C for the HPC and 17 °C for the FCM and ATP measurements respectively) and vice versa. A high level of similarity between water and biofilm communities, >98% and >70–94% respectively, indicates that the extension of the DDWS did not affect either the microbial quality of fresh drinking water or the biofilm composition. Full article

(This article belongs to the Section Water Quality and Contamination)

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12 pages, 2047 KiB

Open AccessArticle

Effect of Alternative Irrigation Strategies on Yield and Quality of Fiesta Raisin Grapes Grown in California

by Isabel Abrisqueta¹ and James E. Ayars^2,*

¹ Visiting Scientist, Irrigation Dpt., CEBAS-CSIC, P.O. Box 164, 30100 Murcia, Spain

² Research Agricultural Engineer, USDA Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648-9757, USA

Water 2018, 10(5), 583; https://doi.org/10.3390/w10050583 - 30 Apr 2018

Cited by 7 | Viewed by 4776

Abstract

Traditionally, grapes are fully irrigated, but alternative irrigation strategies to reduce applied irrigation water may be necessary in the future as occurrences of drought increase. This study was conducted in the San Joaquin Valley (SJV) of California from 2012 to 2014. Three irrigation [...] Read more.

Traditionally, grapes are fully irrigated, but alternative irrigation strategies to reduce applied irrigation water may be necessary in the future as occurrences of drought increase. This study was conducted in the San Joaquin Valley (SJV) of California from 2012 to 2014. Three irrigation treatments were used to study the effects on the yield and quality of Fiesta grapes. The treatments included: grower irrigation (GI) weekly irrigation lasting for approximately 65 h; sustained deficit (SD) equal to 80% of the GI treatment; and regulated deficit (RD) equal to 50% of the GI until fruit set when it was increased to 80% of the GI through harvest and reduced to 50% of the GI after harvest. Average water use across treatments was ≈489 mm. Average yield across all treatments was 7.9 t ha⁻¹, 9.1 t ha⁻¹ and 11.8 t ha⁻¹ in 2012, 2013, and 2014, respectively. Yield was sustained in SD and RD, with up to a 20% reduction in applied water use compared to GI. There were no differences in raisin quality and grade among any of the treatments in any year. The percentage of substandard grapes decreased from an average of 12.6% in 2012 to 3.6% in 2013 and 2014. Growers may use a sustained deficit approach during periods of limited water availability to minimize the effect on yield. Full article

(This article belongs to the Special Issue Innovation Issues in Water, Agriculture and Food)

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17 pages, 2047 KiB

Open AccessArticle

Evaluation of Different Clinoptilolite Zeolites as Adsorbent for Ammonium Removal from Highly Concentrated Synthetic Wastewater

by Stephan Wasielewski^1,*, Eduard Rott¹

, Ralf Minke¹ and Heidrun Steinmetz²

¹ Institute for Sanitary Engineering, Water Quality and Solid Waste Management (ISWA), University of Stuttgart, Bandtaele 2, 70569 Stuttgart, Germany

² Faculty of Civil Engineering, University of Kaiserslautern, Paul-Ehrlich-Str. 14, 67663 Kaiserslautern, Germany

Water 2018, 10(5), 584; https://doi.org/10.3390/w10050584 - 30 Apr 2018

Cited by 42 | Viewed by 6187 | Correction

Abstract

The supply of food to the growing world population requires an increasing amount of nitrogen fertilizers, which can be achieved both by the energy-intensive Haber–Bosch process and by recovering ammonium from wastewater. Within the scope of this work, it is investigated to what [...] Read more.

The supply of food to the growing world population requires an increasing amount of nitrogen fertilizers, which can be achieved both by the energy-intensive Haber–Bosch process and by recovering ammonium from wastewater. Within the scope of this work, it is investigated to what extent different clinoptilolites (CLIs) can be used as ion-exchangers for the removal of ammonium from highly concentrated solutions. To this end, finely ground CLIs with different grain sizes (EcoZeo 20 and CCP 20: 0–20 µm, Micro 200: 0–200 µm) were tested for their sorption properties by varying the parameters of the sorption solution (c₀ = 1000 mg NH₄-N/L) such as pH, temperature, or contact time. All three CLIs tested were effective at adsorbing ammonium. In a pH range from 2 to 8, all CLIs were able to eliminate ammonium equally well. Furthermore, a contact time of 60 min was sufficient to achieve 84–88% of the maximum load. At a temperature of 34 °C, the highest loading was achieved (investigated range: 10–34 °C), indicating that the adsorption process of all CLIs was exergonic and endothermic. Especially for wastewater streams with high ammonium concentrations such as sludge water from wastewater treatment plants, CLI proved to be suitable to adsorb ammonium. Full article

(This article belongs to the Section Wastewater Treatment and Reuse)

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20 pages, 5895 KiB

Open AccessArticle

Extraction of Urban Water Bodies from High-Resolution Remote-Sensing Imagery Using Deep Learning

by Yang Chen^1,2,*, Rongshuang Fan², Xiucheng Yang³, Jingxue Wang¹ and Aamir Latif⁴

¹ School of Geomatics, Liaoning Technical University, Fuxin 123000, China

² Chinese Academy of Surveying and Mapping, Beijing 100830, China

³ ICube Laboratory, University of Strasbourg, 67000 Strasbourg, France

⁴ Institute of Geographic Sciences and Natural Resources Research, University of Chinese Academy of Sciences, Beijing 10010, China

Water 2018, 10(5), 585; https://doi.org/10.3390/w10050585 - 1 May 2018

Cited by 215 | Viewed by 14802

Abstract

Accurate information on urban surface water is important for assessing the role it plays in urban ecosystem services in the context of human survival and climate change. The precise extraction of urban water bodies from images is of great significance for urban planning [...] Read more.

Accurate information on urban surface water is important for assessing the role it plays in urban ecosystem services in the context of human survival and climate change. The precise extraction of urban water bodies from images is of great significance for urban planning and socioeconomic development. In this paper, a novel deep-learning architecture is proposed for the extraction of urban water bodies from high-resolution remote sensing (HRRS) imagery. First, an adaptive simple linear iterative clustering algorithm is applied for segmentation of the remote-sensing image into high-quality superpixels. Then, a new convolutional neural network (CNN) architecture is designed that can extract useful high-level features of water bodies from input data in a complex urban background and mark the superpixel as one of two classes: an including water or no-water pixel. Finally, a high-resolution image of water-extracted superpixels is generated. Experimental results show that the proposed method achieved higher accuracy for water extraction from the high-resolution remote-sensing images than traditional approaches, and the average overall accuracy is 99.14%. Full article

(This article belongs to the Special Issue Flood Forecasting Using Machine Learning Methods)

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15 pages, 1722 KiB

Open AccessArticle

Hydrogeological Properties Estimation from Groundwater Level Natural Fluctuations Analysis as a Low-Cost Tool for the Mexicali Valley Aquifer

by Mario A. Fuentes-Arreazola^1,*

, Jorge Ramírez-Hernández²

and Rogelio Vázquez-González¹

¹ Departamento de Geofísica Aplicada, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), 22860 Ensenada, Baja California, Mexico

² Instituto de Ingeniería, Universidad Autónoma de Baja California, UABC, 21280, Mexicali, Baja California, Mexico

Water 2018, 10(5), 586; https://doi.org/10.3390/w10050586 - 1 May 2018

Cited by 25 | Viewed by 5840

Abstract

Data on the hydrologic properties of aquifers are frequently not available or are spatially limited; additionally, their determination through aquifer tests is often logistically complicated and economically expensive. This study aimed to estimate aquifer properties by analyzing the water level response for the [...] Read more.

Data on the hydrologic properties of aquifers are frequently not available or are spatially limited; additionally, their determination through aquifer tests is often logistically complicated and economically expensive. This study aimed to estimate aquifer properties by analyzing the water level response for the effects of barometric pressure and earth tide. Harmonic analysis of the time series of water level and barometric pressure recorded in three boreholes in the Mexicali aquifer provided reasonable values of porosity, specific storage, transmissivity, and compressibility of the rock materials that constitute the alluvial aquifer. The representative values of porosity (14–20%), specific storage (1.74–6.23 × 10⁻⁶ m^–1), transmissivity (8.57–8.66 × 10⁻⁷ m²·s^–1), and compressibility (3.90–8.21 × 10⁻¹⁰ Pa^–1) were obtained. These values were consistent with the sediment types identified in the proximity of the wells analyzed. The results of this study show that the analysis of water level response to natural phenomena is a low-cost tool that provides reasonable estimates of aquifer properties. This advantage is particularly relevant in the study of aquifers where the available hydrological information is insufficient. Full article

(This article belongs to the Section Hydrology)

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15 pages, 2333 KiB

Open AccessArticle

Hydraulic Performance of Lined Permeable Pavement Systems in the Built Environment

by Jan Støvring^*

, Torben Dam and Marina Bergen Jensen

Department of Geosciences and Natural Resource Management, University of Copenhagen, DK-1958 Frederiksberg, Denmark

Water 2018, 10(5), 587; https://doi.org/10.3390/w10050587 - 1 May 2018

Cited by 15 | Viewed by 5208

Abstract

The hydraulic performance of permeable pavement (PP) systems has been well demonstrated when based on full or partial on-site infiltration, while there is only limited research on lined PP systems built to provide detention and volume reduction by evaporation only. In this study, [...] Read more.

The hydraulic performance of permeable pavement (PP) systems has been well demonstrated when based on full or partial on-site infiltration, while there is only limited research on lined PP systems built to provide detention and volume reduction by evaporation only. In this study, we tested the performance of commercially available PP components when constructed as lined PP systems with un-throttled discharge to explore basic hydraulic function in a real-life-setting. Four types of PP surface products and three types of sub-base aggregates were tested in six unique combinations, built as side-by-side parking lots into an existing parking area, each stall having a size of 25 m² and 0.5 m of depth with individual lining. Based on 12 months of monitoring precipitation and discharge from each stall, total volume reduction ranged from 3% to 37%. Analysis of up to 22 single events, representing return periods of up to two years, revealed marked detention capacities, expressed as median volume reduction of 40%, spanning 27–69% and median lag time of 1:38 h, spanning 0:39–3:16 h, across all stalls. The considerable range in hydraulic properties can be ascribed to both surface and sub-base properties. Full article

(This article belongs to the Special Issue Permeable Pavements and Their Role in Sustainable Urban Development)

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22 pages, 7149 KiB

Open AccessArticle

Assessment of Historical Flood Risk to the Groundwater Regime: Case Study of the Kolubara Coal Basin, Serbia

by Dušan Polomčić, Dragoljub Bajić^*

and Jelena Ratković

Faculty of Mining and Geology, University of Belgrade, Dušina 7, 11000 Belgrade, Serbia

Water 2018, 10(5), 588; https://doi.org/10.3390/w10050588 - 2 May 2018

Cited by 7 | Viewed by 4787

Abstract

Heavy rainfall and slow movement of the cyclone Tamara caused record floods in May 2014 across Serbia. As a result, levees were breached, a large portion of the open-pit lignite mine Tamnava–West Field was flooded and a flood lake was created. Due to [...] Read more.

Heavy rainfall and slow movement of the cyclone Tamara caused record floods in May 2014 across Serbia. As a result, levees were breached, a large portion of the open-pit lignite mine Tamnava–West Field was flooded and a flood lake was created. Due to an active hydraulic link with aquifers, the water table rose and the amount of stored groundwater increased dramatically. Based on in situ surveys and hydrodynamic modeling, three distinct periods of the groundwater regime are identified and the flood impact on the groundwater regime in the study area quantified. The paper describes correlations between flood lake water levels and the water table, and shows calculated groundwater volumes as a result of flooding and those of residual groundwater after dewatering of the open-pit mine. This extreme historical flood in Serbia had disastrous economic and social consequences, given that the studied open-pit mine supports more than 25% of Serbia’s electric power output. The assessment of the flood wave and its impact on the groundwater regime is an important example of the groundwater system response to an extreme rainfall and flood event. The paper presents the operating algorithm which leads to the approach of assessing the impact of floods on increasing the volume of accumulated groundwater. The paper presents a developed methodology for groundwater level status exploration in the wider area of open-pit mine Tamnava-West Field during the flooding that occurred in this mine. The developed method encompasses the creation and calibration of a groundwater model and fate and transport model for groundwater state prior to the flooding, a verification model for groundwater level during the extreme floods and a control verification model which corresponds to the period after the passing of the flood wave. The applied operational algorithm offers reliable bases for adopting a strategy for groundwater management during floods. Full article

(This article belongs to the Section Hydrology)

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16 pages, 13833 KiB

Open AccessArticle

Fast Simulation of Large-Scale Floods Based on GPU Parallel Computing

by Qiang Liu, Yi Qin^* and Guodong Li

Key Laboratory of the North-West Water Resources and Ecology Environment, Ministry of Education, Xi’an University of Technology, Xi’an 710048, China

Water 2018, 10(5), 589; https://doi.org/10.3390/w10050589 - 2 May 2018

Cited by 21 | Viewed by 5590

Abstract

Computing speed is a significant issue of large-scale flood simulations for real-time response to disaster prevention and mitigation. Even today, most of the large-scale flood simulations are generally run on supercomputers due to the massive amounts of data and computations necessary. In this [...] Read more.

Computing speed is a significant issue of large-scale flood simulations for real-time response to disaster prevention and mitigation. Even today, most of the large-scale flood simulations are generally run on supercomputers due to the massive amounts of data and computations necessary. In this work, a two-dimensional shallow water model based on an unstructured Godunov-type finite volume scheme was proposed for flood simulation. To realize a fast simulation of large-scale floods on a personal computer, a Graphics Processing Unit (GPU)-based, high-performance computing method using the OpenACC application was adopted to parallelize the shallow water model. An unstructured data management method was presented to control the data transportation between the GPU and CPU (Central Processing Unit) with minimum overhead, and then both computation and data were offloaded from the CPU to the GPU, which exploited the computational capability of the GPU as much as possible. The parallel model was validated using various benchmarks and real-world case studies. The results demonstrate that speed-ups of up to one order of magnitude can be achieved in comparison with the serial model. The proposed parallel model provides a fast and reliable tool with which to quickly assess flood hazards in large-scale areas and, thus, has a bright application prospect for dynamic inundation risk identification and disaster assessment. Full article

(This article belongs to the Section Hydraulics and Hydrodynamics)

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13 pages, 1650 KiB

Open AccessFeature PaperArticle

Assessment of the Water Treatment Process’s Empirical Model Predictions for the Management of Aesthetic and Health Risks Associated with Cyanobacteria

by Arash Zamyadi^1,2,*, Rita K. Henderson³, Kelly Newton⁴, Jose Capelo-Neto⁴

and Gayle Newcombe⁴

¹ UNSW Water Research Centre, School of Civil and Environmental Engineering, The University of New South Wales (UNSW Sydney), Sydney, NSW H3T 1J4, Australia

² Civil, Mineral and Mining Engineering Department, École Polytechnique de Montreal, Montreal, QC H3C 3A7, Canada

³ The bioMASS Lab, School of Chemical Engineering, The University of New South Wales (UNSW Sydney), Sydney, NSW H3T 1J4, Australia

⁴ South Australian Water Corporation (SA Water), Adelaide, SA 5001, Australia

Water 2018, 10(5), 590; https://doi.org/10.3390/w10050590 - 2 May 2018

Cited by 8 | Viewed by 5812

Abstract

Potentially toxic cyanobacteria have been increasingly detected worldwide in water supply systems in recent years. The management of cyanobacteria in source water and through drinking water treatment processes has been a focus of global research for over thirty years. However, despite the volume [...] Read more.

Potentially toxic cyanobacteria have been increasingly detected worldwide in water supply systems in recent years. The management of cyanobacteria in source water and through drinking water treatment processes has been a focus of global research for over thirty years. However, despite the volume of research outcomes and the publication of guidance documents, gaps still exist in the knowledge base that inhibits the confident application of individual treatment strategies for the mitigation of aesthetic and health risks associated with cyanobacteria and their metabolites at the full-scale. The main objective of this project is to deliver a suite of tools and other resources to the water industry to support the implementation of a regulatory framework for the management of water quality for the assessment and management of aesthetic and toxicity risks associated with cyanobacteria. This study includes (1) the development of a guide (based on real-world examples) for treatment plant operators to perform plant audits and investigative sampling to assess the risk associated with cyanobacteria in their plants, and validate the performance of existing unit processes, and (2) the validation of a treatment model that can be applied at any plant and used to as a guide to the removals of cyanobacteria and metabolites and the expected quality of treated water under a range of challenges from cyanobacteria. Full-scale sampling was undertaken at three Australian regions in 14 water treatment plants to validate the model. The results presented in this paper represent a comprehensive database of full-scale removal efficiencies of 2-methylisoborneol (MIB) and geosmin for a range of water quality and treatment processes. The major findings and conclusions from this project include: (1) the investigative sampling procedures developed are effective and have been successfully applied by utilities; and (2) while routine monitoring data is important, investigative sampling within the water treatment plant provides more detailed and insightful information about the effectiveness of unit processes within the plant. This paper also identifies the knowledge gaps and needs for further studies. Full article

(This article belongs to the Special Issue Eutrophication of Waterways: An Old Problem with Modern Consequences)

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7 pages, 673 KiB

Open AccessFeature PaperCommunication

Avoiding the Use of Exhausted Drinking Water Filters: A Filter-Clock Based on Rusting Iron

by Arnaud Igor Ndé-Tchoupé¹, Mesia Lufingo²

, Rui Hu³, Willis Gwenzi⁴, Seteno Karabo Obed Ntwampe⁵

, Chicgoua Noubactep^6,*

and Karoli N. Njau²

¹ Department of Chemistry, Faculty of Sciences, University of Douala, Douala BP 24157, Cameroon

² Department of Water and Environmental Science and Engineering, Nelson Mandela African Institution of Science and Technology, Arusha 447, Tanzania

³ School of Earth Science and Engineering, Hohai University, Fo Cheng Xi Road 8, Nanjing 211100, China

⁴ Biosystems and Environmental Engineering Research Group, Department of Soil Science and Agricultural Engineering, Faculty of Agriculture, University of Zimbabwe, P.O. Box MP167, Mount Pleasant, Harare, Zimbabwe

⁵ Bioresource Engineering Research Group (BioERG), Department of Biotechnology, Cape Peninsula University of Technology, P.O. Box 652, Cape Town 8000, South Africa

⁶ Department of Applied Geology, University of Göttingen, Goldschmidtstraße 3, D-37077 Göttingen, Germany

Water 2018, 10(5), 591; https://doi.org/10.3390/w10050591 - 2 May 2018

Cited by 9 | Viewed by 6199

Abstract

Efficient but affordable water treatment technologies are currently sought to solve the prevalent shortage of safe drinking water. Adsorption-based technologies are in the front-line of these efforts. Upon proper design, universally applied materials (e.g., activated carbons, bone chars, metal oxides) are able to [...] Read more.

Efficient but affordable water treatment technologies are currently sought to solve the prevalent shortage of safe drinking water. Adsorption-based technologies are in the front-line of these efforts. Upon proper design, universally applied materials (e.g., activated carbons, bone chars, metal oxides) are able to quantitatively remove inorganic and organic pollutants as well as pathogens from water. Each water filter has a defined removal capacity and must be replaced when this capacity is exhausted. Operational experience has shown that it may be difficult to convince some low-skilled users to buy new filters after a predicted service life. This communication describes the quest to develop a filter-clock to encourage all users to change their filters after the designed service life. A brief discussion on such a filter-clock based on rusting of metallic iron (Fe⁰) is presented. Integrating such filter-clocks in the design of water filters is regarded as essential for safeguarding public health. Full article

(This article belongs to the Section Wastewater Treatment and Reuse)

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11 pages, 1848 KiB

Open AccessArticle

Brooks–Corey Modeling by One-Dimensional Vertical Infiltration Method

by Xuguang Xing^1,2, Heng Wang^1,2 and Xiaoyi Ma^1,2,*

¹ College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling 712100, China

² Key Laboratory for Agricultural Soil and Water Engineering in Arid Area of Ministry of Education, Northwest A&F University, Yangling 712100, China

Water 2018, 10(5), 593; https://doi.org/10.3390/w10050593 - 3 May 2018

Cited by 11 | Viewed by 4929

Abstract

The laboratory methods used for the soil water retention curve (SWRC) construction and parameter estimation is time-consuming. A vertical infiltration method was proposed to estimate parameters α and n and to further construct the SWRC. In the present study, the relationships describing the [...] Read more.

The laboratory methods used for the soil water retention curve (SWRC) construction and parameter estimation is time-consuming. A vertical infiltration method was proposed to estimate parameters α and n and to further construct the SWRC. In the present study, the relationships describing the cumulative infiltration and infiltration rate with the depth of the wetting front were established, and simplified expressions for estimating α and n parameters were proposed. The one-dimensional vertical infiltration experiments of four soils were conducted to verify if the proposed method would accurately estimate α and n. The fitted values of α and n, obtained from the RETC software, were consistent with the calculated values obtained from the infiltration method. The comparison between the measured SWRCs obtained from the centrifuge method and the calculated SWRCs that were based on the infiltration method displayed small values of root mean square error (RMSE), mean absolute percentage error (MAPE), and mean absolute error. SWMS_2D-based simulations of cumulative infiltration, based on the calculated α and n, remained consistent with the measured values due to small RMSE and MAPE values. The experiments verified the proposed one-dimensional vertical infiltration method, which has applications in field hydraulic parameter estimation. Full article

(This article belongs to the Section Hydraulics and Hydrodynamics)

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17 pages, 2847 KiB

Open AccessArticle

Opportunities and Limits of Using Meteorological Reanalysis Data for Simulating Seasonal to Sub-Daily Water Temperature Dynamics in a Large Shallow Lake

by Marieke A. Frassl^1,2,*

, Bertram Boehrer¹, Peter L. Holtermann³, Weiping Hu⁴, Knut Klingbeil^3,5, Zhaoliang Peng⁴, Jinge Zhu⁴ and Karsten Rinke¹

¹ UFZ, Helmholtz Centre for Environmental Research, Department of Lake Research, Brückstraße 3 a, D-39114 Magdeburg, Germany

² Australian Rivers Institute, Griffith University, 170 Kessels Rd, Nathan, QLD 4111, Australia

³ Leibniz Institute for Baltic Sea Research, Seestraße 15, D-18119 Rostock-Warnemünde, Germany

⁴ State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China

⁵ Department of Mathematics, University of Hamburg, Bundesstraße 55, D-20146 Hamburg, Germany

Water 2018, 10(5), 594; https://doi.org/10.3390/w10050594 - 3 May 2018

Cited by 20 | Viewed by 4698

Abstract

In lakes and reservoirs, physical processes control temperature dynamics and stratification, which are important determinants of water quality. In large lakes, even extensive monitoring programs leave some of the patterns undiscovered and unresolved. Lake models can complement measurements in higher spatial and temporal [...] Read more.

In lakes and reservoirs, physical processes control temperature dynamics and stratification, which are important determinants of water quality. In large lakes, even extensive monitoring programs leave some of the patterns undiscovered and unresolved. Lake models can complement measurements in higher spatial and temporal resolution. These models require a set of driving data, particularly meteorological input data, which are compulsory to the models but at many locations not available at the desired scale or quality. It remains an open question whether these meteorological input data can be acquired in a sufficient quality by employing atmospheric models. In this study, we used the European Centre for Medium-Range Weather Forecasts’ (ECMWF) ERA-Interim atmospheric reanalysis data as meteorological forcing for the three-dimensional hydrodynamic General Estuarine Transport Model (GETM). With this combination, we modelled the spatio-temporal variation in water temperature in the large, shallow Lake Chaohu, China. The model succeeded in reproducing the seasonal patterns of cooling and warming. While the model did predict diurnal patterns, these patterns were not precise enough to correctly estimate the extent of short stratification events. Nevertheless, applying reanalysis data proved useful for simulating general patterns of stratification dynamics and seasonal thermodynamics in a large shallow lake over the year. Utilising reanalysis data together with hydrodynamic models can, therefore, inform about water temperature dynamics in the respective water bodies and, by that, complement local measurements. Full article

(This article belongs to the Section Hydraulics and Hydrodynamics)

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12 pages, 1975 KiB

Open AccessArticle

Prediction and Optimization of the Fenton Process for the Treatment of Landfill Leachate Using an Artificial Neural Network

by Anita Maslahati Roudi¹, Shreeshivadasan Chelliapan^2,*

, Wan Hanna Melini Wan Mohtar³ and Hesam Kamyab²

¹ Department of Environmental Engineering, Faculty of Civil Engineering, Universiti Teknologi Malaysia, Johor Bahru 81310, Malaysia

² UTM Razak School of Engineering and Advanced Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, Kuala Lumpur 54100, Malaysia

³ Department of Civil and Structural Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, UKM Bangi, Selangor Darul Ehsan 43600, Malaysia

Water 2018, 10(5), 595; https://doi.org/10.3390/w10050595 - 4 May 2018

Cited by 93 | Viewed by 5232

Abstract

In this study, the artificial neural network (ANN) technique was employed to derive an empirical model to predict and optimize landfill leachate treatment. The impacts of H2O2:Fe²⁺ ratio, Fe²⁺ concentration, pH and process reaction time were studied closely. The results showed [...] Read more.

In this study, the artificial neural network (ANN) technique was employed to derive an empirical model to predict and optimize landfill leachate treatment. The impacts of H2O2:Fe²⁺ ratio, Fe²⁺ concentration, pH and process reaction time were studied closely. The results showed that the highest and lowest predicted chemical oxygen demand (COD) removal efficiency were 78.9% and 9.3%, respectively. The overall prediction error using the developed ANN model was within −0.625%. The derived model was adequate in predicting responses (R² = 0.9896 and prediction R² = 0.6954). The initial pH, H2O2:Fe²⁺ ratio and Fe²⁺ concentrations had positive effects, whereas coagulation pH had no direct effect on COD removal. Optimized conditions under specified constraints were obtained at pH = 3, Fe²⁺ concentration = 781.25 mg/L, reaction time = 28.04 min and H2O2:Fe²⁺ ratio = 2. Under these optimized conditions, 100% COD removal was predicted. To confirm the accuracy of the predicted model and the reliability of the optimum combination, one additional experiment was carried out under optimum conditions. The experimental values were found to agree well with those predicted, with a mean COD removal efficiency of 97.83%. Full article

(This article belongs to the Section Wastewater Treatment and Reuse)

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20 pages, 13599 KiB

Open AccessArticle

Modeling Hydroclimatic Change in Southwest Louisiana Rivers

by Z. George Xue^1,2,3,*, David J. Gochis⁴, Wei Yu⁴, Barry D. Keim⁵, Robert V. Rohli¹, Zhengchen Zang¹, Kevin Sampson⁴

, Aubrey Dugger⁴, David Sathiaraj^5,6 and Qian Ge⁷

¹ Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA 70803, USA

² Center for Computation and Technology, Louisiana State University, Baton Rouge, LA 70803, USA

³ Coastal Studies Institute, Louisiana State University, Baton Rouge, LA 70803, USA

⁴ National Center for Atmospheric Research, Research Applications Laboratory, Boulder, CO 80305, USA

⁵ Department of Geography & Anthropology, Louisiana State University, Baton Rouge, LA 70803, USA

⁶ NOAA Southern Regional Climate, Louisiana State University, Baton Rouge, LA 70803, USA

⁷ Key Laboratory of Submarine Geoscience, Second Institute of Oceanography, State Oceanic Administration, Hangzhou 320012, China

Water 2018, 10(5), 596; https://doi.org/10.3390/w10050596 - 4 May 2018

Cited by 15 | Viewed by 5367

Abstract

We applied the newly developed WRF-Hydro model to investigate the hydroclimatic trend encompassing the three basins in Southwest Louisiana as well as their connection with large-scale atmospheric drivers. Using the North American Land Data Assimilation System Phase 2 (NLDAS-2), we performed a multi-decadal [...] Read more.

We applied the newly developed WRF-Hydro model to investigate the hydroclimatic trend encompassing the three basins in Southwest Louisiana as well as their connection with large-scale atmospheric drivers. Using the North American Land Data Assimilation System Phase 2 (NLDAS-2), we performed a multi-decadal model hindcast covering the period of 1979–2014. After validating the model’s performance against available observations, trend and wavelet analysis were applied on the time series of hydroclimatic variables from NLDAS-2 (temperature and precipitation) and model results (evapotranspiration, soil moisture, water surplus, and streamflow). Trend analysis of model-simulated monthly and annual time series indicates that the regional climate is warming and drying over the past decades, specifically during spring and summer (growing season). Wavelet analysis reveals that, since the late 1990s, the anomaly of evapotranspiration, soil moisture, and streamflow exhibits high coherency with that of precipitation. Pettitt’s test detects a possible change-point around the year 2004, after which the monthly precipitation decreased from 140 to 120 mm, evapotranspiration slightly increased from 80 to 83 mm, and water surplus decreased from 60 to 38 mm. Changes in regional climate conditions are closely correlated with large-scale climate dynamics such as the Atlantic Multidecadal Oscillation (AMO) and El Niño Southern Oscillation (ENSO). Full article

(This article belongs to the Section Hydrology)

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14 pages, 2510 KiB

Open AccessArticle

Quantitative Assessment of Flow Regime Alteration Using a Revised Range of Variability Methods

by Jinjin Ge^1,2, Wenqi Peng^1,2,*, Wei Huang^1,2, Xiaodong Qu^1,2 and Shailesh Kumar Singh³

¹ State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China

² Department of Water Environment, China Institute of Water Resources and Hydropower Research, Beijing 100038, China

³ National Institute of Water and Atmospheric Research Ltd., Christchurch 8440, New Zealand

Water 2018, 10(5), 597; https://doi.org/10.3390/w10050597 - 4 May 2018

Cited by 30 | Viewed by 5647

Abstract

The Ecological Limits of Hydrologic Alteration (ELOHA) framework, which can be used to determine and implement environmental flows at regional scales, requires accurate flow regime alteration assessment. The widely used range of variability approach (RVA) evaluates flow regime alteration by comparing the distribution [...] Read more.

The Ecological Limits of Hydrologic Alteration (ELOHA) framework, which can be used to determine and implement environmental flows at regional scales, requires accurate flow regime alteration assessment. The widely used range of variability approach (RVA) evaluates flow regime alteration by comparing the distribution of 32 Indicators of Hydrologic Alteration (IHA). However, the traditional RVA method is not comprehensive, because it neglects both the human-induced inner characteristics of one hydrological year (ICOHY) and the positional information of 32 IHA, which are the main factors behind ecosystem alteration. To address these limitations, we propose a revised RVA method that uses the Tanimoto similarity (TS) coefficient to reflect the ICOHY and a first-order connectivity index to reflect the IHA positional information. The yearly Tanimoto alteration (TA) index is measured using the revised RVA method, and the individual alteration (IA) values of each of 32 IHA are calculated using the traditional RVA method. Then, a new index, the overall degree of flow regime alteration (OA), is derived from the TA and IA values. The effectiveness of the revised RVA method is tested in the upper reaches of the Yangtze River, and the results suggest that the revised RVA ameliorates the limitations of the traditional RVA, and therefore, is preferable for use in the ELOHA framework. Full article

(This article belongs to the Section Hydrology)

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16 pages, 10765 KiB

Open AccessArticle

Assessing the Influence of Precipitation on Shallow Groundwater Table Response Using a Combination of Singular Value Decomposition and Cross-Wavelet Approaches

by Peng Qi^1,2

, Guangxin Zhang^1,*, Y. Jun Xu^3,4

, Lei Wang⁵, Changchun Ding⁶ and Chunyang Cheng⁶

¹ Key Laboratory of Wetland ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, No. 4888, Shengbei Street, Changchun 130102, China

² University of the Chinese Academy of Sciences, Beijing 100049, China

³ School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA

⁴ Coastal Studies Institute, Louisiana State University, Baton Rouge, LA 70803, USA

⁵ British Geological Survey, Keyworth, Nottingham NG12 5GG, UK

⁶ Heilongjiang Province Water Conservancy & Hydropower Investigation, Design and ResearInstitute of the Ministry of Water Resources, Harbin 150080, China

Water 2018, 10(5), 598; https://doi.org/10.3390/w10050598 - 4 May 2018

Cited by 29 | Viewed by 4826

Abstract

Identifying the spatiotemporal change of the groundwater table to precipitation at the river basin scale can be important for regional water resource management. In this study, we proposed a method that combines singular value decomposition and cross-wavelet approaches to analyze the relationship between [...] Read more.

Identifying the spatiotemporal change of the groundwater table to precipitation at the river basin scale can be important for regional water resource management. In this study, we proposed a method that combines singular value decomposition and cross-wavelet approaches to analyze the relationship between groundwater level dynamics and precipitation. The method was applied to the Naoli River Basin, Northeast China. Moreover, the method of continuous wavelet using fast Fourier transform was also used to reveal clearly the relationship between groundwater level and heavy precipitation. The results showed that the major mode of relationship between groundwater and precipitation was divided into four patterns in the study area. In general, the lag time is 27.4 (standard deviation: ±8.1) days in pattern 1, 107.5 (standard deviation: ±13.2) days in pattern 2, 139.9 (standard deviation: ±11.2) days in pattern 3, and 173.4 (standard deviation: ±20.3) days in pattern 4, respectively. In addition, the response of groundwater level dynamics is very sensitive to heavy precipitation in all patterns. Therefore, enhancing the utilization of heavy rainfall and flood resources is an effective way to increase groundwater recharge in this basin. Full article

(This article belongs to the Section Hydrology)

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27 pages, 10088 KiB

Open AccessArticle

Hydrological Modeling in Data-Scarce Catchments: The Kilombero Floodplain in Tanzania

by Kristian Näschen^1,*

, Bernd Diekkrüger¹

, Constanze Leemhuis¹, Stefanie Steinbach¹, Larisa S. Seregina^2,3

, Frank Thonfeld¹

and Roderick Van der Linden^2,3

¹ Department of Geography, University of Bonn, Meckenheimer Allee 166, 53115 Bonn, Germany

² Institute for Geophysics and Meteorology, University of Cologne, Pohligstr. 3, 50969 Cologne, Germany

³ Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, 76128 Karlsruhe, Germany

Water 2018, 10(5), 599; https://doi.org/10.3390/w10050599 - 4 May 2018

Cited by 50 | Viewed by 10149

Abstract

Deterioration of upland soils, demographic growth, and climate change all lead to an increased utilization of wetlands in East Africa. This considerable pressure on wetland resources results in trade-offs between those resources and their related ecosystem services. Furthermore, relationships between catchment attributes and [...] Read more.

Deterioration of upland soils, demographic growth, and climate change all lead to an increased utilization of wetlands in East Africa. This considerable pressure on wetland resources results in trade-offs between those resources and their related ecosystem services. Furthermore, relationships between catchment attributes and available wetland water resources are one of the key drivers that might lead to wetland degradation. To investigate the impacts of these developments on catchment-wetland water resources, the Soil and Water Assessment Tool (SWAT) was applied to the Kilombero Catchment in Tanzania, which is like many other East African catchments, as it is characterized by overall data scarcity. Due to the lack of recent discharge data, the model was calibrated for the period from 1958–1965 (R² = 0.86, NSE = 0.85, KGE = 0.93) and validated from 1966–1970 (R² = 0.80, NSE = 0.80, KGE = 0.89) with the sequential uncertainty fitting algorithm (SUFI-2) on a daily resolution. Results show the dependency of the wetland on baseflow contribution from the enclosing catchment, especially in dry season. Main contributions with regard to overall water yield arise from the northern mountains and the southeastern highlands, which are characterized by steep slopes and a high share of forest and savanna vegetation, respectively. Simulations of land use change effects, generated with Landsat images from the 1970s up to 2014, show severe shifts in the water balance components on the subcatchment scale due to anthropogenic activities. Sustainable management of the investigated catchment should therefore account for the catchment–wetland interaction concerning water resources, with a special emphasis on groundwater fluxes to ensure future food production as well as the preservation of the wetland ecosystem. Full article

(This article belongs to the Special Issue Hydrological Modelling and Remote Sensing: Selected Papers from the 2017 and 2018 SWAT International Conferences)

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16 pages, 14859 KiB

Open AccessArticle

Ecological Flow Assessment to Improve the Spawning Habitat for the Four Major Species of Carp of the Yangtze River: A Study on Habitat Suitability Based on Ultrasonic Telemetry

by Lixiong Yu^1,2, Junqiang Lin³, Daqing Chen^1,2,*, Xinbin Duan^2,*, Qidong Peng³ and Shaoping Liu²

¹ Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Science, Southwest University, Chongqing 400715, China

² Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Science, Wuhan 430223, China

³ China Institute of Water Resources and Hydropower Research, Bejing 100038, China

Water 2018, 10(5), 600; https://doi.org/10.3390/w10050600 - 4 May 2018

Cited by 34 | Viewed by 6559

Abstract

Four major species of Chinese carp, namely black carp (Mylopharyngodon piceus), grass carp (Ctenopharyngodon idellus), silver carp (Hypophthalmichthys molitrix) and bighead carp (Hypophthalmichthys nobilis), are important economic freshwater fish varieties in China. They primarily inhabit and [...] Read more.

Four major species of Chinese carp, namely black carp (Mylopharyngodon piceus), grass carp (Ctenopharyngodon idellus), silver carp (Hypophthalmichthys molitrix) and bighead carp (Hypophthalmichthys nobilis), are important economic freshwater fish varieties in China. They primarily inhabit and breed in the Yangtze River. Unfortunately, the construction and operation of the Gezhouba Dam and the Three Gorges Dam have dramatically changed the hydrodynamic conditions in the middle reaches of the Yangtze River, leading to a sharp decline in the reproduction rates of these carp. The egg abundance of the four species of carp downstream from the Three Gorges Dam reached 8.35 billion in 1965, but abundance during 2005–2012 was only 0.25 billion. One of the main reasons was that the hydrodynamic conditions of the spawning ground could not meet the four species’ breeding requirements. However, due to the limitations of traditional detection tools, the spawning characteristics of these four species of carp were still unclear. In this study, the ultrasonic telemetry and a three–dimensional hydrodynamic model were utilized to build the habitat suitability index (HSI) curves for the four species of carp. The habitat suitability model was then built based on HSI curves to assess spawning habitat quantity under different flow conditions. Finally, the habitat suitability model in the Yidu spawning ground was validated using 32 groups of sampling data in 2015 and 2017. The statistical results showed that the most suitable velocity ranged from 0.78 m/s to 0.93 m/s. The most suitable water depth ranged from 14.56 m to 16.35 m, and the most suitable Froude number ranged from 0.049 to 0.129. The habitat suitability model simulation results indicated that when the discharge was between 15,000 m³/s and 21,300 m³/s, the weighted usable area (WUA) values in both the Yidu and Zhicheng spawning grounds would remain at a high level. The validation results showed that most spawning activities occurred at a high level of WUA, and that the daily spawning egg numbers increased with the WUA value. Therefore, discharges of between 15,000 m³/s and 21,300 m³/s could be recommended as ecological operation target flows. We propose a feasible ecological operation scheme by setting the initial flow at 15,000 m³/s and maintaining the daily discharge increase at 1500 m³/s for 4 days. Full article

(This article belongs to the Section Hydrology)

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19 pages, 3475 KiB

Open AccessArticle

Simulation of Soil Wetting Pattern of Vertical Moistube-Irrigation

by Yan-Wei Fan^1,2, Ning Huang^1,*, Jie Zhang¹ and Tong Zhao²

¹ Key Laboratory of Mechanics on Disaster and Environment in Western China, the Ministry of Education of China, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000, China

² College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou 730050, China

Water 2018, 10(5), 601; https://doi.org/10.3390/w10050601 - 4 May 2018

Cited by 43 | Viewed by 5916

Abstract

Knowledge of the soil wetting pattern characteristics of vertical moistube-irrigation is essential for the design of cost-effective and efficient irrigation systems. We conducted laboratory experiments to determine the specific discharge calculation formula and compare the accuracy of HYDRUS-2D simulation. The cumulative infiltrations, wetting [...] Read more.

Knowledge of the soil wetting pattern characteristics of vertical moistube-irrigation is essential for the design of cost-effective and efficient irrigation systems. We conducted laboratory experiments to determine the specific discharge calculation formula and compare the accuracy of HYDRUS-2D simulation. The cumulative infiltrations, wetting pattern distances, and water content distributions predicted with HYDRUS-2D were found to align well with experimental data. The results provide support for using HYDRUS-2D as a tool for investigating and designing moistube-irrigation management practices. Numerical simulations were carried out with HYDRUS-2D to investigate the influence of soil texture, initial water content, pressure head, moistube length, and buried depth on wetting pattern characteristics. There are small differences in the shape of the soil wetting pattern, as well as significant differences in size. The wetting pattern and water content contour are approximately “ellipsoid” around the moistube. Soil texture has a significant effect on the wetting pattern characteristics, the vertical and horizontal wetting front distance, and the wetted soil volume decrease along with the increase of soil clay content. The initial water content, pressure head, and moistube length have great influence on the wetting front distance and the wetted soil volume. Both are positively correlated with the initial water content, pressure head, and length. Moistube buried depth affects the wetting pattern position. The soil wetting pattern decreases synchronously as the buried depth drops. Full article

(This article belongs to the Section Water Use and Scarcity)

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15 pages, 2026 KiB

Open AccessArticle

Spatial Variation in Trophic Structure of Dominant Fish Species in Lake Dongting, China during Dry Season

by Jia Yu^1,2

, Longgen Guo^2,*, Huan Zhang³, Jun Xu², Huaming Hu², Ting Xue¹, Congqiang Luo^2,4, Chunlong Yi², Yufei Hu^2,5, Kaluwa Handi Wasana Lalanthi De Silva² and Ping Xie^2,*

¹ College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China

² Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China

³ School of Life Sciences, Nanchang University, Nanchang 330031, China

⁴ Current address: Collaborative Innovation Center for Efficient and Health Production of Fisheries in Hunan Province, Key Laboratory of Health Aquaculture and Product Processing in Dongting Lake Area of Hunan Province, Hunan University of Arts and Science, Changde 415000, China

⁵ Current address: IDG/McGovern Institute for Brain Research at Tsinghua, School of Life Science, Tsinghua University, Beijing 100084, China

Water 2018, 10(5), 602; https://doi.org/10.3390/w10050602 - 5 May 2018

Cited by 8 | Viewed by 4309

Abstract

Understanding trophic interactions in food webs is crucial to revealing the transfer of substances and energy from primary food sources to consumers in aquatic ecosystems. We hypothesize that the trophic structure of consumers can be significantly affected by primary food sources (pelagic, benthic, [...] Read more.

Understanding trophic interactions in food webs is crucial to revealing the transfer of substances and energy from primary food sources to consumers in aquatic ecosystems. We hypothesize that the trophic structure of consumers can be significantly affected by primary food sources (pelagic, benthic, and littoral sources) through complex trophic interactions. This study used stable isotope analysis and Bayesian mixing models to estimate the trophic levels of fish consumers and the contributions of primary food sources in the three sub-lakes (Eastern, Southern, and Western Dongting) of Lake Dongting, which have different physical and chemical parameters of water, fish species diversity, and plankton (phytoplankton and zooplankton) density. Results showed the differences in community structures of fish among sub-lakes. Fish trophic levels were significantly higher in Eastern Dongting than those in the two other areas. The contributions of primary food sources to fishes were as follows: the pelagic source was the main basal food source in Eastern Dongting, and littoral and pelagic sources played equally essential roles in Southern Dongting; fishes in Western Dongting relied on more benthic source to growth than those in the two other regions. This study can fill gaps in our knowledge of the influence of the underlying food available on trophic structure of consumers by exploring the role of primary food sources and making the trophic structure of consumers in the aquatic food web highly complicated and diverse through control of the distribution of primary food sources. Full article

(This article belongs to the Section Water Quality and Contamination)

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13 pages, 10678 KiB

Open AccessArticle

Phytoplankton Composition and Water Quality of Kamil Abduş Lagoon (Tuzla Lake), Istanbul-Turkey

by Nese Yilmaz^1,*

, Cumhur Haldun Yardimci¹

, Mohamed Elhag²

and Cristina Alina Dumitrache³

¹ Department of Freshwater Resources and Managment, Faculty of Aquatic Sciences, Istanbul University, 34134 Istanbul, Turkey

² Department of Hydrology and Water Resources Management, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, 21589 Jeddah, Saudi Arabia

³ Institute of Biology Bucharest, Romanian Academy, Department of Ecology, Taxonomy and Nature Conservation, 296 Splaiul Independentei, 060031 Bucharest, Romania

Water 2018, 10(5), 603; https://doi.org/10.3390/w10050603 - 5 May 2018

Cited by 17 | Viewed by 5877

Abstract

In the present study, the water quality and pollution status of Kamil Abduş Lagoon (Tuzla Lake), which is located in Istanbul Metropolitan area, were investigated by determining the phytoplankton composition, some physicochemical parameters, and nutrient concentrations. Water samples were collected at 3 sampling [...] Read more.

In the present study, the water quality and pollution status of Kamil Abduş Lagoon (Tuzla Lake), which is located in Istanbul Metropolitan area, were investigated by determining the phytoplankton composition, some physicochemical parameters, and nutrient concentrations. Water samples were collected at 3 sampling sites between February 2016 and January 2017 on a monthly basis. A total of 32 taxa, belonging to Bacillariophyta (12), Charophyta (1), Chlorophyta (4), Cryptophyta (1), Cyanobacteria (5), Euglenozoa (5) and Miozoa (4) divisions were identified. Both freshwater and marine species were recorded in the study area. The presence of mesotrophic and eutrophic species of phytoplankton, high concentrations of chlorophyll-a and nutrients indicated that the trophic level of the lake is near to eutrophic. Water quality parameters studied in the current research were investigated to evaluate the input data significance using Artificial Neural Network analysis, specifically to ensure the limitation of regression analysis overfitting. Due to the fact that the lagoon is under threat by pollution it needs to be urgently protected. Therefore, detailed studies on phytoplankton including physicochemical parameters and nutrients have to be carried out in order to select appropriate management routes for improving the water quality in the lagoon. Full article

(This article belongs to the Special Issue Hydrology, Water Resources Management and Protection of the Marine Environment–Selected Papers from the 15th International Conference on Environmental Science And Technology (CEST2017))

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36 pages, 2379 KiB

Open AccessArticle

Performance of National Maps of Watershed Integrity at Watershed Scales

by Anne Kuhn^1,*

, Scott G. Leibowitz²

, Zachary C. Johnson^3,4

, Jiajia Lin^2,5

, Jordan A. Massie^2,6, Jeffrey W. Hollister¹

, Joseph L. Ebersole², James L. Lake¹, Jonathan R. Serbst¹, Jennifer James⁷, Micah G. Bennett⁷

, J. Renée Brooks²

, Christopher T. Nietch⁸

, Nathan J. Smucker⁹

, Joseph E. Flotemersch⁹, Laurie C. Alexander⁷ and Jana E. Compton²

¹ U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Atlantic Ecology Division, Narragansett, RI 02882, USA

² U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory,Western Ecology Division, Corvallis, OR 97333, USA

³ U.S. Environmental Protection Agency, Oak Ridge Institute for Science and Education (ORISE), National Health and Environmental Effects Research Laboratory, Western Ecology Division, 200 SW 35th St., Corvallis, OR 97333, USA

⁴ School of Environmental and Forest Sciences, University ofWashington, Seattle, WA 98195, USA

⁵ National Research Council Post-Doctoral Fellow, National Academy of Sciences, Washington, DC 20001, USA

⁶ Department of Earth & Environment, Florida International University, Miami, FL 33199, USA

⁷ U.S. Environmental Protection Agency, National Center for Environmental Assessment, Washington, DC 20001, USA

⁸ U.S. Environmental Protection Agency, National Risk Management Research Laboratory, Cincinnati, OH 45268, USA

⁹ U.S. Environmental Protection Agency, National Exposure Research Laboratory, Cincinnati, OH 45268, USA

Water 2018, 10(5), 604; https://doi.org/10.3390/w10050604 - 5 May 2018

Cited by 10 | Viewed by 5990

Abstract

Watershed integrity, the capacity of a watershed to support and maintain ecological processes essential to the sustainability of services provided to society, can be influenced by a range of landscape and in-stream factors. Ecological response data from four intensively monitored case study watersheds [...] Read more.

Watershed integrity, the capacity of a watershed to support and maintain ecological processes essential to the sustainability of services provided to society, can be influenced by a range of landscape and in-stream factors. Ecological response data from four intensively monitored case study watersheds exhibiting a range of environmental conditions and landscape characteristics across the United States were used to evaluate the performance of a national level Index of Watershed Integrity (IWI) at regional and local watershed scales. Using Pearson’s correlation coefficient (r), and Spearman’s rank correlation coefficient (r_s), response variables displayed highly significant relationships and were significantly correlated with IWI and ICI (Index of Catchment Integrity) values at all watersheds. Nitrogen concentration and flux-related watershed response metrics exhibited significantly strong negative correlations across case study watersheds, with absolute correlations (|r|) ranging from 0.48 to 0.97 for IWI values, and 0.31 to 0.96 for ICI values. Nitrogen-stable isotope ratios measured in chironomids and periphyton from streams and benthic organic matter from lake sediments also demonstrated strong negative correlations with IWI values, with |r| ranging from 0.47 to 0.92, and 0.35 to 0.89 for correlations with ICI values. This evaluation of the performance of national watershed and catchment integrity metrics and their strong relationship with site level responses provides weight-of-evidence support for their use in state, local and regionally focused applications. Full article

(This article belongs to the Section Water Resources Management, Policy and Governance)

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20 pages, 11098 KiB

Open AccessArticle

Experimental and Numerical Modelling of Bottom Intake Racks with Circular Bars

by José M. Carrillo^*

, Juan T. García

and Luis G. Castillo

Civil Engineering Department, Universidad Politécnica de Cartagena, Paseo Alfonso XIII, 52, 30203 Cartagena, Spain

Water 2018, 10(5), 605; https://doi.org/10.3390/w10050605 - 6 May 2018

Cited by 15 | Viewed by 4278

Abstract

Bottom rack intake systems are one of the most popular structures for diverting water in steep rivers. Intake systems may be used in ephemeral rivers beds to capture part of the runoff flow in the rainy season. Their behavior has mainly been studied [...] Read more.

Bottom rack intake systems are one of the most popular structures for diverting water in steep rivers. Intake systems may be used in ephemeral rivers beds to capture part of the runoff flow in the rainy season. Their behavior has mainly been studied in the laboratory. Nevertheless, it is not possible to analyze the whole problem of characterization with traditional methodologies due to the many effects that occur on the bars. Computational fluid dynamics simulations have been considered as a complement to improve the knowledge of the hydraulic phenomenon. However, the geometry of circular racks may be a challenge due to its complexity. After the validation procedure, the numerical models appear to be a good tool to design intake systems. No remarkable differences were obtained between the three two-equation turbulence models tested. The results show differences of less than 1% in flow profile over the rack. Fit curves have been proposed to estimate the flow profile over the rack with r² > 95%. Expressions to calculate the discharge coefficient and the collected water through the rack in the clear water case have been proposed and show a good agreement with the laboratory data. Full article

(This article belongs to the Section Hydraulics and Hydrodynamics)

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18 pages, 6138 KiB

Open AccessEditor’s ChoiceArticle

Risk Analysis for Reservoir Real-Time Optimal Operation Using the Scenario Tree-Based Stochastic Optimization Method

by Yimeng Sun^1,2, Feilin Zhu^1,*, Juan Chen^1,3 and Jinshu Li⁴

¹ College of Hydrology and Water Resources, Hohai University, No.1 Xikang Road, Nanjing 210098, China

² State Key Laboratory of Hydrology Water Resources and Hydraulic Engineering, Hohai University, No.1 Xikang Road, Nanjing 210098, China

³ School of Earth Sciences and Engineering, Hohai University, No.1 Xikang Road, Nanjing 210098, China

⁴ Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, USA

Water 2018, 10(5), 606; https://doi.org/10.3390/w10050606 - 6 May 2018

Cited by 17 | Viewed by 4508

Abstract

The inherent uncertainty of inflow forecasts hinders the reservoir real-time optimal operation. This paper proposes a risk analysis model for reservoir real-time optimal operation using the scenario tree-based stochastic optimization method. We quantify the probability distribution of inflow forecast uncertainty by developing the [...] Read more.

The inherent uncertainty of inflow forecasts hinders the reservoir real-time optimal operation. This paper proposes a risk analysis model for reservoir real-time optimal operation using the scenario tree-based stochastic optimization method. We quantify the probability distribution of inflow forecast uncertainty by developing the relationship between two forecast accuracy metrics and the standard deviation of relative forecast error. An inflow scenario tree is generated via Monte Carlo simulation to represent the uncertain inflow forecasts. We establish a scenario tree-based stochastic optimization model to explicitly incorporate inflow forecast uncertainty into the stochastic optimization process. We develop a risk analysis model based on the principle of maximum entropy (POME) to evaluate the uncertainty propagation process from flood forecasts to optimal operation. We apply the proposed methodology to a flood control system in the Daduhe River Basin, China. In addition, numerical experiments are carried out to investigate the effect of two different forecast accuracy metrics and different forecast accuracy levels on reservoir optimal flood control operation as well as risk analysis. The results indicate that the proposed methods can provide decision-makers with valuable risk information for guiding reservoir real-time optimal operation and enable risk-informed decisions to be made with higher reliabilities. Full article

(This article belongs to the Section Water Resources Management, Policy and Governance)

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16 pages, 1534 KiB

Open AccessArticle

Hidden Cost of Drinking Water Treatment and Its Relation with Socioeconomic Status in Nepalese Urban Context

by Khadga Bahadur Shrestha^1,*, Bhesh Raj Thapa², Yoko Aihara³, Sadhana Shrestha⁴

, Arun P. Bhattarai⁵, Niranjan Bista⁵, Futaba Kazama⁶ and Junko Shindo⁶

¹ Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-4-37 Takeda Kofu, Yamanashi 400-8510, Japan

² International Water Management Institute (IWMI), Nepal Office, GPO Box- 8975, EPC 416 Kathmandu, Nepal

³ Kobe Gakuin University, Kobe City, Hyogo 651-2180, Japan

⁴ Interdisciplinary Centre for River Basin Environment, University of Yamanashi, Kofu, Yamanashi 400-8511, Japan

⁵ The Small Earth Nepal (SEN), Tripureshwor, GPO Box-20533 Kathmandu, Nepal

⁶ Graduate Faculty of Interdisciplinary Research, University of Yamanashi, 4-4-37 Takeda Kofu, Yamanashi 400-8510, Japan

Water 2018, 10(5), 607; https://doi.org/10.3390/w10050607 - 6 May 2018

Cited by 16 | Viewed by 7145

Abstract

Kathmandu Valley faces water scarcity from decades of the added burden of water storage and treatment, which imposed cost. We estimated the method-specific cost of in-house drinking water treatment (9 L/day used) based on equipment price and life, daily operation time, fuel used, [...] Read more.

Kathmandu Valley faces water scarcity from decades of the added burden of water storage and treatment, which imposed cost. We estimated the method-specific cost of in-house drinking water treatment (9 L/day used) based on equipment price and life, daily operation time, fuel used, and consumables replacement frequency, which were Nepalese Rupees (NRs) 23, 57, 392, 586 and 799 for chemicals, ceramic filter, boiling, Euro-Guard and reverse osmosis-ultraviolet (RO-UV) water purification, respectively. The monthly average water treatment cost was estimated based on these estimates and treatment methods used in households, obtained from a questionnaire survey of 1500 households, and its socioeconomic relationship in a Nepalese urban context was investigated. Of the households, 75% practiced at least one treatment method, (average, 1.4). The estimated monthly average cost per household was NRs 380. The fixed effects model showed that the cost was significantly higher in Lalitpur district, and in high school education households. Higher water insecurity perception of respondents was the main determinant of higher treatment cost, which was especially true in Lalitpur district. Water treatment added extra financial burden, especially for the poor households which should be averted or minimized by concerned authorities to provide adequate quantity, quality, and access to drinking water for all. Full article

(This article belongs to the Section Urban Water Management)

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14 pages, 4248 KiB

Open AccessArticle

Impacts of Land Use Change on River Systems for a River Network Plain

by Lei Wu^1,2,*, Youpeng Xu^1,*, Jia Yuan¹, Yu Xu¹

, Qiang Wang¹, Xing Xu³ and Haiyan Wen⁴

¹ School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210023, China

² Fenner School for Society and Environment, Australian National University, Canberra, ACT 0200, Australia

³ Wuxi Sub-Bureau of Jiangsu Province Hydrology and Water Resources Investigation Bureau, Wuxi 214000, China

⁴ Wuxi Flood Control Engineering Administration, Wuxi 214000, China

Water 2018, 10(5), 609; https://doi.org/10.3390/w10050609 - 7 May 2018

Cited by 23 | Viewed by 4810

Abstract

River systems are crucial for the Earth system. However, they are profoundly impacted by human activities, especially land use change. To reveal the impact of land use change on river systems, river system data and land use data in Suzhou City from the [...] Read more.

River systems are crucial for the Earth system. However, they are profoundly impacted by human activities, especially land use change. To reveal the impact of land use change on river systems, river system data and land use data in Suzhou City from the 1960s to 2010s were analyzed through grid river density on a 3 km × 3 km scale. The spatial-temporal variation was very different for different river orders. The lower the river order, the larger was the variation in the accumulated length (including both an increase and a decrease). The river systems were modified to meet the needs of human development in different social development stages. During the period of agricultural modification, undeveloped land was reclaimed to increase the amount of arable land available, but when the proportion of cultivated land exceeded a threshold level, higher order rivers were invaded, cut off and even buried, which forced a part of the higher order rivers to transform into narrower rivers. During the period of urbanization, higher order rivers were usually dredged, reconstructed and protected to improve the abilities of storage and discharge, and lower order rivers were buried after 40% of the land proportion had been built up. These results provide a reliable foundation on which to formulate policies and manage river systems. Full article

(This article belongs to the Section Water Resources Management, Policy and Governance)

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15 pages, 3330 KiB

Open AccessFeature PaperArticle

Integrated Evaluation of Hybrid Water Supply Systems Using a PROMETHEE–GAIA Approach

by Mukta Sapkota^1,*

, Meenakshi Arora¹, Hector Malano¹

, Ashok Sharma²

and Magnus Moglia³

¹ Department of Infrastructure Engineering, Melbourne School of Engineering, University of Melbourne, Melbourne, VIC 3010, Australia

² ISILC (Institute of Sustainable Industries & Liveable Cities) and College of Engineering and Science, Victoria University, Footscray, VIC 3030, Australia

³ CSIRO Land and Water, Clayton, VIC 3169, Australia

Water 2018, 10(5), 610; https://doi.org/10.3390/w10050610 - 8 May 2018

Cited by 29 | Viewed by 6112

Abstract

There are pressures on existing centralized water infrastructures in urban centers which justify the search for alternatives. An increasingly important alternative is to shift from centralized to hybrid systems, often in response to climate variability and demographic changes. In a hybrid system, water [...] Read more.

There are pressures on existing centralized water infrastructures in urban centers which justify the search for alternatives. An increasingly important alternative is to shift from centralized to hybrid systems, often in response to climate variability and demographic changes. In a hybrid system, water is supplied and discharged through a mix of centralized and decentralized systems. There is usually no single objective that justifies the choice of hybrid water systems, but they typically are justified based on the consideration of a number of different criteria in order to evaluate the overall quality of service provision. The most important criteria include meeting water demand, as well as reducing demand for fresh water and instead using local alternative water supplies. Integration of multiple objectives to evaluate the hybrid water supply systems can be accomplished by multi-criteria decision aid techniques. This paper evaluates a number of hybrid water supply scenarios using a case study based on the Northern Growth Area of Melbourne, Australia. It uses the Preference Ranking Organization METHod for Enrichment Evaluations (PROMETHEE) and Geometrical Analysis for Interactive Decision Aid (GAIA), one of the multi-criteria decision-making methods through D-Sight software, to rank the hybrid water supply scenarios, and this ranking is validated by means of sensitivity analysis. The centralized system combined with stormwater harvesting and the centralized system combined with treated wastewater and rainwater tanks yielded the first and second most preferred scenarios, while the centralized water supply system combined with treated wastewater yielded the worst hybrid water supply option. Full article

(This article belongs to the Special Issue Technologies and Interventions to Support Sustainable Urban Water Management)

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23 pages, 6220 KiB

Open AccessArticle

An Unstructured-Grid Based Morphodynamic Model for Sandbar Simulation in the Modaomen Estuary, China

by Xiaozhang Hu, Fang Yang, Lixiang Song^*

and Hangang Wang

Department of Water Resources and Environment, Pearl River Hydraulic Research Institute, Guangzhou 510611, China

Water 2018, 10(5), 611; https://doi.org/10.3390/w10050611 - 8 May 2018

Cited by 7 | Viewed by 4253

Abstract

The Modaomen Estuary is the most important passageway in discharging flood and sediment of the Pearl River Delta, which is one of the most complex estuarine systems in China. Due to the coupling effect among tidal currents, waves, and sediments, an immense sandbar [...] Read more.

The Modaomen Estuary is the most important passageway in discharging flood and sediment of the Pearl River Delta, which is one of the most complex estuarine systems in China. Due to the coupling effect among tidal currents, waves, and sediments, an immense sandbar area evolved in the outer subaqueous delta, impeding the flood releasing during wet season, as well as salinity intrusion during the dry season. In this work, an unstructured-grid based morphodynamic model was proposed to simulate the sandbar evolution process in the Modaomen Estuary. The proposed model was constructed by using the two-dimensional shallow water equations for tidal flow, the advection-diffusion equations for salinity and suspended sediment transport, and the non-equilibrium formulation of the Exner equation for bed evolution. To simulate the wave-induced longshore currents in the Modaomen Estuary, an adaptive time-stepping approach was proposed to couple the unstructured-grid based Simulating WAves Nearshore (SWAN) model and the shallow flow model. An integrated solver is proposed for computing flow, salinity, and sediment transport fluxes simultaneously, and then the shallow water equations and advection-diffusion equations are jointly solved by a high-resolution, unstructured-grid Godunov method. Application of the model to the Modaomen Estuary, using calibrated parameter values, gives results comparable to the measured data. The butterfly shape of the sandbar in the Modaomen Estuary is considerably well simulated by the proposed model, which matches well with the measured topography. Full article

(This article belongs to the Special Issue Water Resources and Environmental Fluid Mechanics: From the Glacier to the Lake/Ocean)

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18 pages, 1928 KiB

Open AccessArticle

Performance Analysis of Ageing Single-Jet Water Meters for Measuring Residential Water Consumption

by Francisco J. Arregui^1,*

, Francesc J. Gavara², Javier Soriano¹ and Laura Pastor-Jabaloyes¹

¹ ITA—Grupo de Ingeniería y Tecnología del Agua, Dpto. de Ingeniería del Agua y Medio Ambiente, Universitat Politecnica Valencia, Camino de Vera s/n, 46022 Valencia, Spain

² Smart Metering Manager, FACSA, Calle Mayor 82-84, 12001 Castellon, Spain

Water 2018, 10(5), 612; https://doi.org/10.3390/w10050612 - 8 May 2018

Cited by 24 | Viewed by 9635

Abstract

Single-jet meters are one of the most frequently used domestic meters that can be found in water distribution systems. Like any other water meter technology, they have significant metrological limitations that prevent them, even if recently installed, from measuring all water consumption of [...] Read more.

Single-jet meters are one of the most frequently used domestic meters that can be found in water distribution systems. Like any other water meter technology, they have significant metrological limitations that prevent them, even if recently installed, from measuring all water consumption of a domestic customer. After installation, their metrological characteristics evolve depending on the particular design of the meters and their actual working conditions in the field. This work presents a comprehensive set of tests to determine the initial and after installation weighted error of two types of domestic single-jet water meters. Three non-linear degradation models have been derived from the tests results. These models consider age, totalised volume, or both parameters simultaneously as drivers of the weighted error. The results show that even though the construction of the two examined meters is similar, they have been working under comparable operational conditions and measuring water of the same quality, there is a significant difference in the performance between both types. This result highlights the need to conduct individual analyses for each meter type and the impossibility of generalizing conclusions on how the weighted error could evolve over time. Full article

(This article belongs to the Special Issue Advances in the Economic Analysis of Residential Water Use)

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15 pages, 5762 KiB

Open AccessArticle

Use of a Non-Ionic Water Surfactant in Lettuce Fertigation for Optimizing Water Use, Improving Nutrient Use Efficiency, and Increasing Crop Quality

by Alessandra Trinchera^*

and Valentina Baratella

Council for Agricultural Research and Economics, Research Center for Agriculture and Environnent (CREA-AA), Via della Navicella 2-4, 00184 Rome, Italy

Water 2018, 10(5), 613; https://doi.org/10.3390/w10050613 - 8 May 2018

Cited by 10 | Viewed by 5911

Abstract

The use of water surfactants in fertigation constitutes a viable approach to increase soil wetting, potentially improving crop nutrient uptake and quality. An in-field demonstration test was carried out by applying an innovative, eco-friendly, non-ionic surfactant to fertigation water in Lactuca sativa (var. [...] Read more.

The use of water surfactants in fertigation constitutes a viable approach to increase soil wetting, potentially improving crop nutrient uptake and quality. An in-field demonstration test was carried out by applying an innovative, eco-friendly, non-ionic surfactant to fertigation water in Lactuca sativa (var. Iceberg) production to increase nutrient use efficiency and improve the crop’s access to water. A non-ionic methyl-oxirane surfactant (methyl-oxirane + 2-methyl-oxirane) was added at an increasing rate to the fertigation solution (Hoagland). Upon harvesting, the main growth and nutritional parameters were determined on the aboveground and belowground portions of the lettuce. Leaf nitrate content, water, and nitrogen use efficiency were recorded; the relationship of lettuce aboveground dry biomass with nutrient uptake was evaluated using vectorial analysis; and ultrastructural analysis of lettuce roots was performed by scanning electron microscopy. The surfactant, applied by fertigation at the rate of 1.0 mL × L_Hoagland⁻¹, improved crop P, K, Mn, and Fe use efficiency. When applied by fertigation, although the surfactant did not increase the water use efficiency index, it induced a significant decrease of the specific leaf water content (−8.8%) and an increase of the leaf area (+13.3%). By comparison with the recent literature, we inferred a positive physiological response by more expanded and less thick leaves in lettuce, likely by the optimization of the crop water and nutrient root uptakes mediated by the abundant but shortest lateral roots. This finding corresponded to the lowest leaf nitrate content, indicating an improvement of the lettuce quality without losing the crop yield. Full article

(This article belongs to the Special Issue Soil Water Conservation: Dynamics and Impact)

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20 pages, 7058 KiB

Open AccessArticle

Case Study: On Objective Functions for the Peak Flow Calibration and for the Representative Parameter Estimation of the Basin

by Jungwook Kim¹, Deokhwan Kim¹, Hongjun Joo¹, Huiseong Noh², Jongso Lee^3,* and Hung Soo Kim¹

¹ Department of Civil Engineering, Inha University, Incheon 22212, Korea

² Department of Land, Water and Environment Research, Korea Institute of Civil Engineering and Building Technolody (KICT), Goyang 10223, Korea

³ Urban Disaster Prevention & Water Resource Research Center, Korea Research Institute for Human Settlement, Sejong 30147, Korea

Water 2018, 10(5), 614; https://doi.org/10.3390/w10050614 - 9 May 2018

Cited by 5 | Viewed by 4175

Abstract

The objective function is usually used for verification of the optimization process between observed and simulated flows for the parameter estimation of rainfall–runoff model. However, it does not focus on peak flow and on representative parameter for various rain storm events of the [...] Read more.

The objective function is usually used for verification of the optimization process between observed and simulated flows for the parameter estimation of rainfall–runoff model. However, it does not focus on peak flow and on representative parameter for various rain storm events of the basin, but it can estimate the optimal parameters by minimizing the overall error of observed and simulated flows. Therefore, the aim of this study is to suggest the objective functions that can fit peak flow in hydrograph and estimate the representative parameter of the basin for the events. The Streamflow Synthesis And Reservoir Regulation (SSARR) model was employed to perform flood runoff simulation for the Mihocheon stream basin in Geum River, Korea. Optimization was conducted using three calibration methods: genetic algorithm, pattern search, and the Shuffled Complex Evolution method developed at the University of Arizona (SCE-UA). Two objective functions of the Sum of Squared of Residual (SSR) and the Weighted Sum of Squared of Residual (WSSR) suggested in this study for peak flow optimization were applied. Since the parameters estimated using a single rain storm event do not represent the parameters for various rain storms in the basin, we used the representative objective function that can minimize the sum of objective functions of the events. Six rain storm events were used for the parameter estimation. Four events were used for the calibration and the other two for validation; then, the results by SSR and WSSR were compared. Flow runoff simulation was carried out based on the proposed objective functions, and the objective function of WSSR was found to be more useful than that of SSR in the simulation of peak flow runoff. Representative parameters that minimize the objective function for each of the four rain storm events were estimated. The calibrated observed and simulated flow runoff hydrographs obtained from applying the estimated representative parameters to two different rain storm events were better than those retrieved from parameters estimated using a single rain storm event. The results of this study demonstrated that WSSR is adequate in peak flow simulation, that is, the estimation of peak flood runoff. In addition, representative parameters can be applied to a flow runoff simulation for rain storm events that were not involved in parameter estimation. Full article

(This article belongs to the Section Hydrology)

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14 pages, 4378 KiB

Open AccessArticle

Application of a Steady Meandering River with Piers Using a Lattice Boltzmann Sub-Grid Model in Curvilinear Coordinate Grid

by Liping Chen¹

, Zhuangming Zhao²

and Ping Huang^1,*

¹ Department of Environmental Science, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China

² South China Institute of Environmental Sciences, The Ministry of Environmental Protection of PRC, Guangzhou 510655, China

Water 2018, 10(5), 615; https://doi.org/10.3390/w10050615 - 9 May 2018

Cited by 1 | Viewed by 3376

Abstract

A sub-grid multiple relaxation time (MRT) lattice Boltzmann model with curvilinear coordinates is applied to simulate an artificial meandering river. The method is based on the D2Q9 model and standard Smagorinsky sub-grid scale (SGS) model is introduced to simulate meandering flows. The interpolation [...] Read more.

A sub-grid multiple relaxation time (MRT) lattice Boltzmann model with curvilinear coordinates is applied to simulate an artificial meandering river. The method is based on the D2Q9 model and standard Smagorinsky sub-grid scale (SGS) model is introduced to simulate meandering flows. The interpolation supplemented lattice Boltzmann method (ISLBM) and the non-equilibrium extrapolation method are used for second-order accuracy and boundary conditions. The proposed model was validated by a meandering channel with a 180° bend and applied to a steady curved river with piers. Excellent agreement between the simulated results and previous computational and experimental data was found, showing that MRT-LBM (MRT lattice Boltzmann method) coupled with a Smagorinsky sub-grid scale (SGS) model in a curvilinear coordinates grid is capable of simulating practical meandering flows. Full article

(This article belongs to the Section Hydraulics and Hydrodynamics)

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22 pages, 4098 KiB

Open AccessArticle

A Non-Equilibrium Sediment Transport Model for Dam Break Flow over Moveable Bed Based on Non-Uniform Rectangular Mesh

by Gangfeng Wu¹, Zhehao Yang¹, Kefeng Zhang^1,*, Ping Dong^1,2 and Ying-Tien Lin³

¹ School of Civil Engineering and Architecture, Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, China

² School of Engineering, University of Liverpool, Liverpool L69 3GH, UK

³ Ocean College, Zhejiang University, Hangzhou 310058, China

Water 2018, 10(5), 616; https://doi.org/10.3390/w10050616 - 9 May 2018

Cited by 12 | Viewed by 4953

Abstract

The use of multiple-level non-uniform rectangular mesh in coupled flow and sediment transport modeling is preferred to achieve high accuracy in important region without increasing computational cost greatly. Here, a robust coupled hydrodynamic and non-equilibrium sediment transport model is developed on non-uniform rectangular [...] Read more.

The use of multiple-level non-uniform rectangular mesh in coupled flow and sediment transport modeling is preferred to achieve high accuracy in important region without increasing computational cost greatly. Here, a robust coupled hydrodynamic and non-equilibrium sediment transport model is developed on non-uniform rectangular mesh to simulate dam break flow over movable beds. The enhanced shallow water and sediment transport equations are adopted to consider the mass and momentum exchange between the flow phase and sediment phase. The flux at the interface is calculated by the positivity preserving central upwind scheme, which belongs to Godunov-type Riemann-problem-solver-free central schemes and is less expensive than other popular Riemann solvers while still capable of tracking wet/dry fronts accurately. The nonnegative water depth reconstruction method is used to achieve second-order accuracy in space. The model was first verified against two laboratory experiments of dam break flow over irregular fixed bed. Then the quantitative performance of the model was further investigated by comparing the computational results with measurement data of dam break flow over movable bed. The good agreements between the measurements and the numerical simulations are found for the flow depth, velocity and bed changes. Full article

(This article belongs to the Section Hydraulics and Hydrodynamics)

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19 pages, 9529 KiB

Open AccessArticle

Time-Lapse Photography of the Edge-of-Water Line Displacements of a Sandbar as a Proxy of Riverine Morphodynamics

by Michael Nones^1,2,*

, Renata Archetti³

and Massimo Guerrero³

¹ Interdepartmental Centre for Industrial Research in Building and Construction, University of Bologna, 40126 Bologna, Italy

² Department of Hydrology and Water Resources Management, Brandenburg University of Technology, 03046 Cottbus, Germany

³ Department of Civil, Chemical, Environmental, and Materials Engineering, University of Bologna, 40126 Bologna, Italy

Water 2018, 10(5), 617; https://doi.org/10.3390/w10050617 - 9 May 2018

Cited by 13 | Viewed by 4938

Abstract

A simple methodology to track the displacements of a sandbar from a fixed video camera, extracting its morphological features and deriving the associated fluvial morphology is presented, using a small reach of the Po River in Italy as a case study. A camera [...] Read more.

A simple methodology to track the displacements of a sandbar from a fixed video camera, extracting its morphological features and deriving the associated fluvial morphology is presented, using a small reach of the Po River in Italy as a case study. A camera fixed on a bridge pier acquired images every twelve hours while hourly water levels are derived from a radar hydrometer located upstream of the study area. The quantification of the fluvial bathymetry is achieved by mapping multiple edge-of-water lines of a sandbar before and after high flow conditions in December 2017. Both from video information and 2-D numerical simulations, it is evident that flooding waves can easily remove sediments that accumulated on bars during low flow conditions in this area, redistributing them across the river channel. This video-based methodology—which confirms to be economically attractive if compared to more traditional monitoring systems—proves to be a valuable system to monitor long-term fluvial processes providing detailed indications on how to better plan river management activities. Full article

(This article belongs to the Special Issue Watershed Hydrology, Erosion and Sediment Transport Processes )

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18 pages, 3135 KiB

Open AccessArticle

Evaluation of Unified Algorithms for Remote Sensing of Chlorophyll-a and Turbidity in Lake Shinji and Lake Nakaumi of Japan and the Vaal Dam Reservoir of South Africa under Eutrophic and Ultra-Turbid Conditions

by Yuji Sakuno^1,*

, Hiroshi Yajima²

, Yumi Yoshioka³, Shogo Sugahara⁴, Mohamed A. M. Abd Elbasit^5,6

, Elhadi Adam⁶

and Johannes George Chirima⁵

¹ Graduate School of Engineering, Hiroshima University, Higashihiroshima 739-8527, Japan

² Estuary Research Center, Shimane University, Matsue 690-8504, Japan

³ Faculty of Agriculture, Tottori University, Tottori 680-8550, Japan

⁴ Graduate School of Science and Engineering, Shimane University, Matsue 690-8504, Japan

⁵ Agricultural Research Council-Institute for Soil, Climate and Water, Pretoria 0001, South Africa

⁶ School of Geography, Archaeology, and Environmental Studies, University of the Witwatersrand, Johannesburg 2000, South Africa

Water 2018, 10(5), 618; https://doi.org/10.3390/w10050618 - 9 May 2018

Cited by 25 | Viewed by 6931

Abstract

We evaluated unified algorithms for remote sensing of chlorophyll-a (Chla) and turbidity in eutrophic and ultra-turbid waters such as Japan’s Lake Shinji and Lake Nakaumi (SJNU) and the Vaal Dam Reservoir (VDR) in South Africa. To realize this objective, we used 38 remote [...] Read more.

We evaluated unified algorithms for remote sensing of chlorophyll-a (Chla) and turbidity in eutrophic and ultra-turbid waters such as Japan’s Lake Shinji and Lake Nakaumi (SJNU) and the Vaal Dam Reservoir (VDR) in South Africa. To realize this objective, we used 38 remote sensing reflectance (R_rs), Chla and turbidity datasets collected in these waters between July 2016 and March 2017. As a result, we clarified the following items. As a unified Chla model, we obtained strong correlation (R² = 0.7, RMSE = 2 mg m⁻³) using a two-band model (2-BM) and three-band model (3-BM), with R_rs(687)/R_rs(672) and [R_rs⁻¹(687) − R_rs⁻¹(672)] × R_rs(832). As a unified turbidity model, we obtained strong correlation (R² = 0.7, RMSE = 260 NTU) using 2-BM and 3-BM, with R_rs(763)/R_rs(821) and R_rs(810) − [R_rs(730) + R_rs(770)]/2. When targeting the Sentinel-2 Multispectral Imager (MSI) frequency band, we focused on MSI Bands 4 and 5 (R_rs(740) and R_rs(775)) for the Chla algorithm. When optically separating SJNU and VDR data, it is effective to use the slopes of MSI Bands 3 and 4 (R_rs(560) and R_rs(665)) and the slopes of MSI Bands 7 and 9 (R_rs(775) and R_rs(865)). Full article

(This article belongs to the Section Water Quality and Contamination)

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16 pages, 2314 KiB

Open AccessArticle

Decrease in Snow Cover over the Aysén River Catchment in Patagonia, Chile

by Tomás Pérez^1,*

, Cristian Mattar² and Rodrigo Fuster³

¹ Laboratory for Analysis of the Biosphere (LAB), University of Chile, Avenida Santa Rosa N° 11315, 8820808 Santiago, Chile

² University of Aysén, Calle Obispo Vielmo N° 62, 5952039 Coyhaique, Chile

³ Department of Environmental Sciences and Renewable Natural Resources, Faculty of Agricultural Sciences, University of Chile, Avenida Santa Rosa N° 11315, 8820808 Santiago, Chile

Water 2018, 10(5), 619; https://doi.org/10.3390/w10050619 - 10 May 2018

Cited by 21 | Viewed by 6308

Abstract

The evidence for global warming can be seen in various forms, such as glacier shrinkage, sea ice retreat, sea level rise and air temperature increases. The magnitude of these changes tends to be critical over pristine and extreme biomes. Chilean Patagonia is one [...] Read more.

The evidence for global warming can be seen in various forms, such as glacier shrinkage, sea ice retreat, sea level rise and air temperature increases. The magnitude of these changes tends to be critical over pristine and extreme biomes. Chilean Patagonia is one of the most pristine and uninhabited regions in the world, home to some of the most important freshwater reservoirs as well as to evergreen forest, lakes and fiords. Furthermore, this region presents a sparse and weak network of ground stations which must be complemented with satellite information to determine trends on biophysical parameters. The main objective of this work is to present the first assessment on snow cover over the Aysén basin in Patagonia-Chile by using Moderate Resolution Imaging Spectroradiometer (MODIS) data from the period 2000–2016. The MOD10A2 product was processed at 500 × 500 m spatial resolution. The time-series analysis consisted in the application of non-parametric tests such as the Mann–Kendall test and Sen’s slope for annual and seasonal mean of snow covered area (SCA). Data from ground meteorological network and river discharges were also included in this work to show the trends in air temperature, precipitation and stream flow during the last decades. Results indicate that snow cover shows a decreasing non-significant trend in annual mean SCA with a −20.01 km²⋅year⁻¹ slope, and neither seasonal mean shows statistical significance. The comparison with in situ data shows a seasonal decrease in stream flows and precipitation during summer. The hydrological year 2016 was the year with the most negative standardized joint anomalies in the period. However, the lack of in situ snow-monitoring stations in addition to the persistence of cloud cover over the basin can impact trends, creating some uncertainties in the data. Finally, this work provides an initial analysis of the possible impacts of global warming as seen by snow cover in Chilean Patagonia. Full article

(This article belongs to the Section Hydrology)

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14 pages, 2494 KiB

Open AccessArticle

Potential of Biofilters for Treatment of De-Icing Chemicals

by Gema Sakti Raspati^1,*

, Hanna Kristine Haug Lindseth², Tone Merete Muthanna² and Kamal Azrague^1,*

¹ SINTEF Building and Infrastructure, Water and Environment, Richard Birkelands vei 3A, 7034 Trondheim, Norway

² Department of Civil and Environmental Engineering, Norwegian University of Science and Technology, S.P. Andersens veg 5, 7491 Trondheim, Norway

Water 2018, 10(5), 620; https://doi.org/10.3390/w10050620 - 10 May 2018

Cited by 8 | Viewed by 4503

Abstract

Organic de-icing chemicals, such as propylene glycol and potassium formate, cause environmental degradation in receiving water if left untreated, due to the high organic load resulting in oxygen depletion. Biofilters are commonly used for the treatment of biodegradable organic carbon in water treatment. [...] Read more.

Organic de-icing chemicals, such as propylene glycol and potassium formate, cause environmental degradation in receiving water if left untreated, due to the high organic load resulting in oxygen depletion. Biofilters are commonly used for the treatment of biodegradable organic carbon in water treatment. This study investigated the potential for using biofilters for treating organic de-icing compounds. Lab-scale adsorption tests using filter media made of crushed clay (Filtralite) and granular activated carbon were conducted. Further, a column filtration experiment testing two different crushed clay size ranges was carried out investigating the effect of filter media depth, nutrient addition, and filtration rate. The surrogate parameter used to monitor the removal of de-icing chemicals was dissolved organic carbon (DOC). The adsorption test showed no significant adsorption of DOC was observed. The column test showed that the most active separation occurred in the first ~20 cm of the filter depth. This was confirmed by results from (1) water quality analysis (i.e., DOC removal and adenosine tri-phosphate (ATP) measurement); and (2) calculations based on a filtration performance analysis (Iwasaki model) and filter hydraulic evaluation (Lindquist diagram). The results showed that, for the highest C:N:P ratio tested (molar ratio of 24:7:1), 50–60% DOC removal was achieved. The addition of nutrients was found to be important for determining the biofilter performance. Full article

(This article belongs to the Section Wastewater Treatment and Reuse)

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18 pages, 1930 KiB

Open AccessFeature PaperArticle

Effects of Input Data Content on the Uncertainty of Simulating Water Resources

by Carla Camargos¹

, Stefan Julich², Tobias Houska¹

, Martin Bach¹

and Lutz Breuer^1,3,*

¹ Institute for Landscape Ecology and Resources Management (ILR), Research Centre for BioSystems, Land Use and Nutrition (iFZ), Justus Liebig University Giessen, Heinrich-Buff-Ring 26, 35392 Giessen, Germany

² Institute of Soil Science and Site Ecology, TU Dresden, Pienner Str. 19, 01737 Tharandt, Germany

³ Centre for International Development and Environmental Research (ZEU), Justus Liebig University Giessen, Senckenbergstraße 3, 35390 Giessen, Germany

Water 2018, 10(5), 621; https://doi.org/10.3390/w10050621 - 10 May 2018

Cited by 17 | Viewed by 5264

Abstract

The widely used, partly-deterministic Soil and Water Assessment Tool (SWAT) requires a large amount of spatial input data, such as a digital elevation model (DEM), land use, and soil maps. Modelers make an effort to apply the most specific data possible for the [...] Read more.

The widely used, partly-deterministic Soil and Water Assessment Tool (SWAT) requires a large amount of spatial input data, such as a digital elevation model (DEM), land use, and soil maps. Modelers make an effort to apply the most specific data possible for the study area to reflect the heterogeneous characteristics of landscapes. Regional data, especially with fine resolution, is often preferred. However, such data is not always available and can be computationally demanding. Despite being coarser, global data are usually free and available to the public. Previous studies revealed the importance for single investigations of different input maps. However, it remains unknown whether higher-resolution data can lead to reliable results. This study investigates how global and regional input datasets affect parameter uncertainty when estimating river discharges. We analyze eight different setups for the SWAT model for a catchment in Luxembourg, combining different land-use, elevation, and soil input data. The Metropolis–Hasting Markov Chain Monte Carlo (MCMC) algorithm is used to infer posterior model parameter uncertainty. We conclude that our higher resolved DEM improves the general model performance in reproducing low flows by 10%. The less detailed soil-map improved the fit of low flows by 25%. In addition, more detailed land-use maps reduce the bias of the model discharge simulations by 50%. Also, despite presenting similar parameter uncertainty (P-factor ranging from 0.34 to 0.41 and R-factor from 0.41 to 0.45) for all setups, the results show a disparate parameter posterior distribution. This indicates that no assessment of all sources of uncertainty simultaneously is compensated by the fitted parameter values. We conclude that our result can give some guidance for future SWAT applications in the selection of the degree of detail for input data. Full article

(This article belongs to the Special Issue Quantifying Uncertainty in Integrated Catchment Studies)

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20 pages, 6685 KiB

Open AccessArticle

Indirect Damage of Urban Flooding: Investigation of Flood-Induced Traffic Congestion Using Dynamic Modeling

by Jingxuan Zhu¹, Qiang Dai^1,2,3,*, Yinghui Deng¹, Aorui Zhang¹, Yingzhe Zhang¹ and Shuliang Zhang^1,3,*

¹ Key Laboratory of VGE of Ministry of Education, Nanjing Normal University, Nanjing 210023, China

² Water and Environmental Management Research Centre, Department of Civil Engineering, University of Bristol, Bristol BS8 1TR, UK

³ Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China

Water 2018, 10(5), 622; https://doi.org/10.3390/w10050622 - 10 May 2018

Cited by 39 | Viewed by 6979

Abstract

In many countries, industrialization has led to rapid urbanization. Increased frequency of urban flooding is one consequence of the expansion of urban areas which can seriously affect the productivity and livelihoods of urban residents. Therefore, it is of vital importance to study the [...] Read more.

In many countries, industrialization has led to rapid urbanization. Increased frequency of urban flooding is one consequence of the expansion of urban areas which can seriously affect the productivity and livelihoods of urban residents. Therefore, it is of vital importance to study the effects of rainfall and urban flooding on traffic congestion and driver behavior. In this study, a comprehensive method to analyze the influence of urban flooding on traffic congestion was developed. First, a flood simulation was conducted to predict the spatiotemporal distribution of flooding based on Storm Water Management Model (SWMM) and TELAMAC-2D. Second, an agent-based model (ABM) was used to simulate driver behavior during a period of urban flooding, and a car-following model was established. Finally, in order to study the mechanisms behind how urban flooding affects traffic congestion, the impact of flooding on urban traffic was investigated based on a case study of the urban area of Lishui, China, covering an area of 4.4 km². It was found that for most events, two-hour rainfall has a certain impact on traffic congestion over a five-hour period, with the greatest impact during the hour following the cessation of the rain. Furthermore, the effects of rainfall with 10- and 20-year return periods were found to be similar and small, whereas the effects with a 50-year return period were obvious. Based on a combined analysis of hydrology and transportation, the proposed methods and conclusions could help to reduce traffic congestion during flood seasons, to facilitate early warning and risk management of urban flooding, and to assist users in making informed decisions regarding travel. Full article

(This article belongs to the Section Urban Water Management)

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14 pages, 2521 KiB

Open AccessArticle

Objectives and Indexes for Implementation of Sponge Cities—A Case Study of Changzhou City, China

by Zhengzhao Li¹, Mingjing Dong^2,3, Tony Wong⁴, Jianbin Wang⁴, Alagarasan Jagadeesh Kumar^2,3 and Rajendra Prasad Singh^2,3,*

¹ Changzhou City Planning and Design Institute, Changzhou 213003, China

² School of Civil Engineering, Southeast University, Nanjing 210096, China

³ Southeast University-Monash University Joint Research Centre for Water Sensitive Cities, Nanjing 210096, China

⁴ CRC for Water Sensitive Cities, Clayton, VIC 3800, Australia

Water 2018, 10(5), 623; https://doi.org/10.3390/w10050623 - 10 May 2018

Cited by 26 | Viewed by 8776

Abstract

This paper presents a framework of objectives and indexes for sponge cities implementation in China. The proposed objectives and indexes aims to reflect whether the city is in accord with the sponge city. Different cities have different objectives and indexes as each city [...] Read more.

This paper presents a framework of objectives and indexes for sponge cities implementation in China. The proposed objectives and indexes aims to reflect whether the city is in accord with the sponge city. Different cities have different objectives and indexes as each city has its own geologic and hydrogeological conditions. Therefore, the main problems (e.g., water security and flood risks) in the central urban area of Changzhou city, China were evaluated scientifically. According to the local conditions, four objectives and eleven indexes have been made as a standard to estimate the sponge city and set a goal for the city development to reach the goal of sustainable urban development. The strategy of process control was implemented to improve the standard of urban drainage and flood control facilities, regulate total runoff and reduce storm peak flow, and the ecological monitoring of the function of the rivers and lakes. The objectives of sponge cities include water security, water quality improvement, healthy water ecosystems, and water utilization efficiency. Urban flood prevention capacity, river and lake water quality compliance, and annual runoff control are the key objectives to encourage the use of non-conventional water resources. Full article

(This article belongs to the Special Issue Sponge Cities: Emerging Approaches, Challenges and Opportunities)

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25 pages, 4082 KiB

Open AccessArticle

Year-Round Irrigation Schedule for a Tomato–Maize Rotation System in Reservoir-Based Irrigation Schemes in Ghana

by Ephraim Sekyi-Annan^1,2, Bernhard Tischbein¹, Bernd Diekkrüger³

and Asia Khamzina^4,*

¹ Department of Ecology and Natural Resources Management, Center for Development Research, University of Bonn, Genscherallee 3, 53113 Bonn, Germany

² CSIR-Soil Research Institute, Academy Post Office, Private Mail Bag, Kwadaso-Kumasi, Ghana

³ Department of Geography, University of Bonn, Meckenheimer Allee 166, 53115 Bonn, Germany

⁴ Division of Environmental Science and Ecological Engineering, College of Life Science and Biotechnology, Korea University, 145 Anam-Ro, Seongbuk-Gu, Seoul 02841, Korea

Water 2018, 10(5), 624; https://doi.org/10.3390/w10050624 - 10 May 2018

Cited by 9 | Viewed by 7463

Abstract

Improving irrigation management in semi-arid regions of Sub-Saharan Africa is crucial to respond to increasing variability in rainfall and overcome deficits in current irrigation schemes. In small-scale and medium-scale reservoir-based irrigation schemes in the Upper East region of Ghana, we explored options for [...] Read more.

Improving irrigation management in semi-arid regions of Sub-Saharan Africa is crucial to respond to increasing variability in rainfall and overcome deficits in current irrigation schemes. In small-scale and medium-scale reservoir-based irrigation schemes in the Upper East region of Ghana, we explored options for improving the traditional, dry season irrigation practices and assessed the potential for supplemental irrigation in the rainy season. The AquaCrop model was used to (i) assess current water management in the typical tomato-maize rotational system; (ii) develop an improved irrigation schedule for dry season cultivation of tomato; and (iii) determine the requirement for supplemental irrigation of maize in the rainy season under different climate scenarios. The improved irrigation schedule for dry season tomato cultivation would result in a water saving of 130–1325 mm compared to traditional irrigation practices, accompanied by approximately a 4–14% increase in tomato yield. The supplemental irrigation of maize would require 107–126 mm of water in periods of low rainfall and frequent dry spells, and 88–105 mm in periods of high rainfall and rare dry spells. Therefore, year-round irrigated crop production may be feasible, using water saved during dry season tomato cultivation for supplemental irrigation of maize in the rainy season. Full article

(This article belongs to the Special Issue Water Management for Sustainable Food Production)

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15 pages, 4215 KiB

Open AccessArticle

Morphometric Change Detection of Lake Hawassa in the Ethiopian Rift Valley

by Yonas Abebe^1,*

, Menberu Bitew², Tenalem Ayenew³, Clement Alo⁴, Assegid Cherinet⁵ and Mulugeta Dadi⁶

¹ Ethiopian Institute of Water Resources, Addis Ababa University, P.O. Box 89, Kality, Addis Ababa, Ethiopia

² USDA ARS Southwest Watershed Research Center, 2000 E Allen Road, Tucson, AZ 85719, USA

³ School of Earth Sciences, Addis Ababa University, P.O. Box 1176, AAU, Addis Ababa, Ethiopia

⁴ Earth and Environmental Studies, Montclair State University, 1 Normal Ave., Montclair, NJ 07043, USA

⁵ School of Bio-Systems and Environmental Engineering, Institute of Technology, Hawassa University, P.O. Box 5, Hawassa, Ethiopia

⁶ School of Water Resources Engineering, Institute of Technology, Hawassa University, P.O. Box 5, Hawassa, Ethiopia

Water 2018, 10(5), 625; https://doi.org/10.3390/w10050625 - 10 May 2018

Cited by 17 | Viewed by 8106

Abstract

The Ethiopian Rift Valley lakes have been subjected to environmental and ecological changes due to recent development endeavors and natural phenomena, which are visible in the alterations to the quality and quantity of the water resources. Monitoring lakes for temporal and spatial alterations [...] Read more.

The Ethiopian Rift Valley lakes have been subjected to environmental and ecological changes due to recent development endeavors and natural phenomena, which are visible in the alterations to the quality and quantity of the water resources. Monitoring lakes for temporal and spatial alterations has become a valuable indicator of environmental change. In this regard, hydrographic information has a paramount importance. The first extensive hydrographic survey of Lake Hawassa was conducted in 1999. In this study, a bathymetric map was prepared using advances in global positioning systems, portable sonar sounder technology, geostatistics, remote sensing and geographic information system (GIS) software analysis tools with the aim of detecting morphometric changes. Results showed that the surface area of Lake Hawassa increased by 7.5% in 1999 and 3.2% in 2011 from that of 1985. Water volume decreased by 17% between 1999 and 2011. Silt accumulated over more than 50% of the bed surface has caused a 4% loss of the lake’s storage capacity. The sedimentation patterns identified may have been strongly impacted by anthropogenic activities including urbanization and farming practices located on the northern, eastern and western sides of the lake watershed. The study demonstrated this geostatistical modeling approach to be a rapid and cost-effective method for bathymetric mapping. Full article

(This article belongs to the Section Water Resources Management, Policy and Governance)

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12 pages, 1014 KiB

Open AccessArticle

Bioremediation of Aluminium from the Waste Water of a Conventional Water Treatment Plant Using the Freshwater Macroalga Oedogonium

by David A. Roberts^1,*, Laura Shiels², Julian Tickle², Rocky De Nys¹ and Nicholas A. Paul³

¹ MACRO—The Centre for Macroalgal Resources and Biotechnology, College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia

² Garbutt Operations Centre, Townsville City Council, Dalrymple Road, Garbutt, QLD 4814, Australia

³ Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, QLD 4558, Australia

Water 2018, 10(5), 626; https://doi.org/10.3390/w10050626 - 10 May 2018

Cited by 14 | Viewed by 5214

Abstract

Conventional water treatment processes use aluminium sulphate (alum) as a coagulant in the production of potable water. While alum is an inexpensive and reliable means of treating water, the process generates waste water containing dissolved Al. This waste water is primarily dealt with [...] Read more.

Conventional water treatment processes use aluminium sulphate (alum) as a coagulant in the production of potable water. While alum is an inexpensive and reliable means of treating water, the process generates waste water containing dissolved Al. This waste water is primarily dealt with via on-site retention. In this study we investigate the cultivation of the freshwater macroalga Oedogonium as a means to sequester dissolved Al from waste water from a conventional water treatment plant. Furthermore, we examine the use of CO₂ to manipulate the pH of cultivation as a means of enhancing the sequestration of Al by either increasing the productivity of Oedogonium or increasing the bioavailability of Al in the waste water. The relative bioavailability of Al under conditions of CO₂ and no-CO₂ provision was contrasted by comparing Al uptake by Diffusive Gradients in Thin Films (DGTs). Oedogonium was able to grow rapidly in the waste water (12 g dry weight m⁻² day⁻¹) while consistently sequestering Al. The Oedogonium-treated waste water had a sufficiently low Al concentration that it could be used in unrestricted irrigation in the surrounding region. When CO₂ was added to the waste water containing concentrations of Al up to 8 mg L⁻¹, there was a slight increase (~10%) in the rate of sequestration of Al by Oedogonium relative to waste water not receiving CO₂. This was due to two concurrent processes. The provision of CO₂ increased the productivity of Oedogonium by 15% and the bioavailability of Al by up to 200%, as measured by the DGTs. Despite this strong effect of CO₂ on Al bioavailability, the increase in Al sequestration by Oedogonium when CO₂ was provided was modest (~10%). Al was sequestered by Oedogonium to concentrations below permissible limits for discharge without the need for the addition CO₂. The cultivation of Oedogonium in waste water from conventional treatments plants can simultaneously treat waste water for re-use and provide a biomass source for value-added applications. Full article

(This article belongs to the Section Wastewater Treatment and Reuse)

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18 pages, 3192 KiB

Open AccessArticle

A Simulation-Based Linear Fractional Programming Model for Adaptable Water Allocation Planning in the Main Stream of the Songhua River Basin, China

by Qiang Fu^1,2,3

, Linqi Li¹, Mo Li^1,*

, Tianxiao Li^1,2, Dong Liu^1,2 and Song Cui¹

¹ School of Water Conservancy & Civil Engineering, Northeast Agricultural University, Harbin 150030, China

² Key Laboratory of Effective Utilization of Agricultural Water Resources of Ministry of Agriculture, Northeast Agricultural University, Harbin 150030, China

³ Heilongjiang Provincial Key Laboratory of Water Resources and Water Conservancy Engineering in Cold Region, Northeast Agricultural University, Harbin 150030, China

Water 2018, 10(5), 627; https://doi.org/10.3390/w10050627 - 10 May 2018

Cited by 11 | Viewed by 3766

Abstract

The potential influence of natural variations in a climate system on global warming can change the hydrological cycle and threaten current strategies of water management. A simulation-based linear fractional programming (SLFP) model, which integrates a runoff simulation model (RSM) into a linear fractional [...] Read more.

The potential influence of natural variations in a climate system on global warming can change the hydrological cycle and threaten current strategies of water management. A simulation-based linear fractional programming (SLFP) model, which integrates a runoff simulation model (RSM) into a linear fractional programming (LFP) framework, is developed for optimal water resource planning. The SLFP model has multiple objectives such as benefit maximization and water supply minimization, balancing water conflicts among various water demand sectors, and addressing complexities of water resource allocation system. Lingo and Excel programming solutions were used to solve the model. Water resources in the main stream basin of the Songhua River are allocated for 4 water demand sectors in 8 regions during two planning periods under different scenarios. Results show that the increase or decrease of water supply to the domestic sector is related to the change in population density at different regions in different target years. In 2030, the water allocation in the industrial sector decreased by 1.03–3.52% compared with that in 2020, while the water allocation in the environmental sector increased by 0.12–1.29%. Agricultural water supply accounts for 54.79–77.68% of total water supply in different regions. These changes in water resource allocation for various sectors were affected by different scenarios in 2020; however, water resource allocation for each sector was relatively stable under different scenarios in 2030. These results suggest that the developed SLFP model can help to improve the adjustment of water use structure and water utilization efficiency. Full article

(This article belongs to the Section Water Resources Management, Policy and Governance)

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16 pages, 4689 KiB

Open AccessArticle

Data Pre-Analysis and Ensemble of Various Artificial Neural Networks for Monthly Streamflow Forecasting

by Jianzhong Zhou^1,2,*, Tian Peng^1,2,*, Chu Zhang^1,2 and Na Sun^1,2

¹ School of Hydropower and Information Engineering, Huazhong University of Science and Technology, Wuhan 430074, China

² Hubei Key Laboratory of Digital Valley Science and Technology, Wuhan 430074, China

Water 2018, 10(5), 628; https://doi.org/10.3390/w10050628 - 13 May 2018

Cited by 82 | Viewed by 6909

Abstract

This paper introduces three artificial neural network (ANN) architectures for monthly streamflow forecasting: a radial basis function network, an extreme learning machine, and the Elman network. Three ensemble techniques, a simple average ensemble, a weighted average ensemble, and an ANN-based ensemble, were used [...] Read more.

This paper introduces three artificial neural network (ANN) architectures for monthly streamflow forecasting: a radial basis function network, an extreme learning machine, and the Elman network. Three ensemble techniques, a simple average ensemble, a weighted average ensemble, and an ANN-based ensemble, were used to combine the outputs of the individual ANN models. The objective was to highlight the performance of the general regression neural network-based ensemble technique (GNE) through an improvement of monthly streamflow forecasting accuracy. Before the construction of an ANN model, data preanalysis techniques, such as empirical wavelet transform (EWT), were exploited to eliminate the oscillations of the streamflow series. Additionally, a theory of chaos phase space reconstruction was used to select the most relevant and important input variables for forecasting. The proposed GNE ensemble model has been applied for the mean monthly streamflow observation data from the Wudongde hydrological station in the Jinsha River Basin, China. Comparisons and analysis of this study have demonstrated that the denoised streamflow time series was less disordered and unsystematic than was suggested by the original time series according to chaos theory. Thus, EWT can be adopted as an effective data preanalysis technique for the prediction of monthly streamflow. Concurrently, the GNE performed better when compared with other ensemble techniques. Full article

(This article belongs to the Special Issue Flood Forecasting Using Machine Learning Methods)

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17 pages, 9770 KiB

Open AccessArticle

Experimental Analysis of the Hydraulic Performance of Filtering Cartridges in Drinking Water Networks

by Giacomo Viccione^1,*

, Stefania Evangelista²

and Giovanni De Marinis²

¹ Department of Civil Engineering, Università degli Studi di Salerno, 84084 Fisciano, Italy

² Department of Civil and Mechanical Engineering, Università di Cassino e del Lazio Meridionale, 03043 Cassino, Italy

Water 2018, 10(5), 629; https://doi.org/10.3390/w10050629 - 11 May 2018

Cited by 5 | Viewed by 4674

Abstract

Liquid treatment processes have been assuming increasing importance in recent decades with the progressive industrialization to ensure public health security for drinking water or to prevent economic damage when safeguarding important production processes. Major investments have been devoted to the research, study, and [...] Read more.

Liquid treatment processes have been assuming increasing importance in recent decades with the progressive industrialization to ensure public health security for drinking water or to prevent economic damage when safeguarding important production processes. Major investments have been devoted to the research, study, and design of innovative products that are able to respond to the demands of the market, which currently offer several solutions, among which filtration treatment still represents a major one. This work focuses, in particular, on filtration of drinking water with filter cartridges, with the aim to test their hydraulic performance and, particularly, to evaluate the head losses that they produce when introduced into a hydraulic system. The local pressure drops, in fact, may compromise hydraulic plants already characterized by low pressures. What is more, this condition is increasingly likely in supplying networks due to the coexistence of several factors, such as water losses due to failures and inefficient maintenance, severe and prolonged droughts, and increased water demand related to social and economic development. In these systems, the insertion of filtration cartridges can make the pressure levels fall below the minimum limit recommended to ensure the smooth operation of domestic devices. More in detail, in the present study the behavior of seven different commercial filter cartridges was analyzed through a set of experiments conducted in a pilot circuit at the Laboratory of Environmental and Maritime Hydraulics (LIDAM), University of Salerno. These tests have been performed in different operating conditions, collecting pressure data through various pressure gauges. The analysis proved that for common values of operating flow rates in domestic plants the pressure drops in the filter can be of the order of some meters and provided some useful information for the choice of the proper cartridge in low-pressure distribution systems. Full article

(This article belongs to the Special Issue Hydrology, Water Resources Management and Protection of the Marine Environment–Selected Papers from the 15th International Conference on Environmental Science And Technology (CEST2017))

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16 pages, 1530 KiB

Open AccessArticle

Simplified Direct Water Footprint Model to Support Urban Water Management

by Wieslaw Fialkiewicz^1,*

, Ewa Burszta-Adamiak¹

, Anna Kolonko-Wiercik², Alessandro Manzardo³

, Andrea Loss³

, Christian Mikovits⁴ and Antonio Scipioni³

¹ Institute of Environmental Engineering, Wroclaw University of Environmental and Life Sciences, pl. Grunwaldzki 24, 50-363 Wroclaw, Poland

² New Technologies Center, Municipal Water and Sewage Company MPWiK S.A., ul. Na Grobli 14/16, 50-421 Wrocław, Poland

³ Department of Industrial Engineering, University of Padova CESQA, via Marzolo 9-35131, Padova, Italy

⁴ Unit of Environmental Engineering, University of Innsbruck, Technikerstrasse 13, A6020 Innsbruck, Austria

Water 2018, 10(5), 630; https://doi.org/10.3390/w10050630 - 12 May 2018

Cited by 16 | Viewed by 6091

Abstract

Water resources conservation corresponding to urban growth is an increasing challenge for European policy makers. Water footprint (WF) is one of the methods to address this challenge. The objective of this study was to develop a simplified model to assess the WF of [...] Read more.

Water resources conservation corresponding to urban growth is an increasing challenge for European policy makers. Water footprint (WF) is one of the methods to address this challenge. The objective of this study was to develop a simplified model to assess the WF of direct domestic and non-domestic water use within an urban area and to demonstrate its effectiveness in supporting new urban water management strategies and solutions. The new model was tested on three Central European urban areas with different characteristics i.e., Wroclaw (Poland), Innsbruck (Austria), and Vicenza (Italy). Obtained WFs varied from 291 dm³/(day∙capita) in Wroclaw, 551 dm³/(day∙capita) in Vicezna to 714 dm³/(day∙capita) in Innsbruck. In addition, WF obtained with the proposed model for the city of Vicenza was compared with a more complex approach. The results proved the model to be robust in providing reasonable results using a small amount of data. Full article

(This article belongs to the Special Issue Progress in Water Footprint Assessment)

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17 pages, 7194 KiB

Open AccessArticle

Effects of Land Cover Change on Urban Floods and Rainwater Harvesting: A Case Study in Sharjah, UAE

by Abdallah Shanableh^1,2, Rami Al-Ruzouq^1,2,*

, Abdullah Gokhan Yilmaz^1,2, Mohsin Siddique^1,2, Tarek Merabtene^1,2

and Monzur Alam Imteaz³

¹ Research Institute of Sciences and Engineering, University of Sharjah, 27272 Sharjah, UAE

² Department of Civil and Environmental Engineering, University of Sharjah, 27272 Sharjah, UAE

³ Civil Engineering Department, Swinburne University of Technology, 3122 Melbourne, Australia

Water 2018, 10(5), 631; https://doi.org/10.3390/w10050631 - 13 May 2018

Cited by 65 | Viewed by 9661

Abstract

In this study, multi-temporal satellite images combined with rainfall data and field observations were used to assess the spatial and temporal changes in urban flooding and urban water harvesting potential in the coastal city of Sharjah, United Arab Emirates (UAE) during the period [...] Read more.

In this study, multi-temporal satellite images combined with rainfall data and field observations were used to assess the spatial and temporal changes in urban flooding and urban water harvesting potential in the coastal city of Sharjah, United Arab Emirates (UAE) during the period from 1976 to 2016. During the study period, the population increased by approximately 14-fold with about a 4-fold increase in built areas. Being in a hot, dry region with average rainfall of about 100 mm/year, the city did not invest in a comprehensive drainage infrastructure. As a result, the frequency, extent and risk associated with urban floods increased significantly. The expansion of built areas progressively increased the impervious land cover in the city, decreasing the minimum precipitation required to generate runoff by approximately 32% and significantly increasing the runoff coefficient. In parallel to rapid urbanization, the urban rainwater harvesting potential significantly increased over 1976–2016. Urban flood maps were generated using three thematic factors: excess rain, land elevation and land slope. The flood maps were confirmed by locating urban flood locations in the field using GPS. This study demonstrates the impact of urbanization through assessing the relationship between urbanization, runoff, local floods and rainwater harvesting potential in Sharjah and provides a basis for developing sustainable urban storm water management practices for the city and similar cities. Full article

(This article belongs to the Special Issue Assessment of Current and Future Vulnerability of Flooding with Hydrologic/Hydraulic Modeling and Remote Sensing Techniques)

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17 pages, 4306 KiB

Open AccessArticle

Physical Hybrid Neural Network Model to Forecast Typhoon Floods

by You-Da Jhong¹, Chang-Shian Chen², Hsin-Ping Lin² and Shien-Tsung Chen^2,*

¹ Construction and Disaster Prevention Research Center, Feng Chia University, Taichung 407, Taiwan

² Department of Water Resources Engineering and Conservation, Feng Chia University, Taichung 407, Taiwan

Water 2018, 10(5), 632; https://doi.org/10.3390/w10050632 - 13 May 2018

Cited by 34 | Viewed by 5795

Abstract

This study proposed a hybrid neural network model that combines a self-organizing map (SOM) and back-propagation neural networks (BPNNs) to model the rainfall-runoff process in a physically interpretable manner and to accurately forecast typhoon floods. The SOM and a two-stage clustering scheme were [...] Read more.

This study proposed a hybrid neural network model that combines a self-organizing map (SOM) and back-propagation neural networks (BPNNs) to model the rainfall-runoff process in a physically interpretable manner and to accurately forecast typhoon floods. The SOM and a two-stage clustering scheme were applied to group hydrologic data into four clusters, each of which represented a meaningful hydrologic component of the rainfall-runoff process. BPNNs were constructed for each cluster to achieve high forecasting capability. The physical hybrid neural network model was used to forecast typhoon flood discharges in Wu River in Taiwan by using two types of rainfall data. The clustering results demonstrated that the rainfall-runoff process was favorably described by the sequence of derived clusters. The flood forecasting results indicated that the proposed hybrid neural network model has good forecasting capability, and the performance of the models using the two types of rainfall data is similar. In addition, the derived lagged inputs are hydrologically meaningful, and the number and activation function of the hidden nodes can be rationally interpreted. This study also developed a traditional, single BPNN model trained using the whole calibration data for comparison with the hybrid neural network model. The proposed physical hybrid neural network model outperformed the traditional neural network model in forecasting the peak discharges and low flows. Full article

(This article belongs to the Special Issue Flood Forecasting Using Machine Learning Methods)

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21 pages, 3447 KiB

Open AccessArticle

Integrated Effects of Land Use and Topography on Streamflow Response to Precipitation in an Agriculture-Forest Dominated Northern Watershed

by Chunying Wang^1,2,3,*, Songhao Shang²

, Dongdong Jia¹, Yuping Han^1,3,*, Sabine Sauvage⁴, José-Miguel Sánchez-Pérez⁴, Kanta Kuramochi⁵ and Ryusuke Hatano⁵

¹ North China University of Water Resources and Electric Power, Zhengzhou 450045, China

² State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, China

³ Henan Key Laboratory of Water Environment Simulation and Treatment, Zhengzhou 450046, China

⁴ EcoLab, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France, Avenue de l’Agrobiopole, 31326 Castanet Tolosan Cedex, France

⁵ Research Faculty of Agriculture, Hokkaido University, Sapporo 0608589, Japan

Water 2018, 10(5), 633; https://doi.org/10.3390/w10050633 - 13 May 2018

Cited by 19 | Viewed by 7998

Abstract

Based on statistical analysis, baseflow separation and wavelet analysis, this research was carried out in Shibetsu River Watershed (SRW), Eastern Hokkaido, Japan, to investigate the integrated effects of land use and topography on streamflow response to precipitation. The agriculture-dominated sub-watershed (AW) showed coupled [...] Read more.

Based on statistical analysis, baseflow separation and wavelet analysis, this research was carried out in Shibetsu River Watershed (SRW), Eastern Hokkaido, Japan, to investigate the integrated effects of land use and topography on streamflow response to precipitation. The agriculture-dominated sub-watershed (AW) showed coupled flat topography/agriculture characteristics, the forest-dominated sub-watershed (FW) had coupled steep topography/forest characteristics, and the mixed agriculture-forested sub-watershed (AFW) had mixed flat topography/agriculture and steep topography/forest characteristics. Precipitation variability is characterized by 6-months and 1-year periods. Coupled forest land/steep topography of the FW can increase surface runoff due to forest surface soil water repellency and steep slope, and might receive more external water and higher precipitation that resulted in the highest baseflow and total streamflow compared with other sub-watersheds. Coupled forest land/steep topography can cause higher monthly streamflow variability than coupled agricultural land/flat topography. The FW streamflow is characterized by 3–4 months, 6 months, and 1-year periods. The AW streamflow is only characterized by 3–4 months and 6 months periods. Coupled agricultural land/flat topography produced similar magnitude of baseflow during snowmelt season (March–May) and rainfall season (July–September), which resulted in the losing of annual periodicity in AW streamflow. The coupled forest land/steep topography can increase synchronicity in precipitation and streamflow at annual and monthly scales than coupled agricultural land/flat topography, except in 2007 under wet antecedent conditions when pasture land has lower rainfall interception and lower surface soil infiltration capacity. The coupled forest land/steep topography can increase time lags between precipitation and streamflow compared to coupled agricultural land/flat topography. Full article

(This article belongs to the Section Hydrology)

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18 pages, 2077 KiB

Open AccessArticle

Analyzing the Role of Shallow Groundwater Systems in the Water Use of Different Land-Use Types in Arid Irrigated Regions

by Dongyang Ren^1,2, Xu Xu^1,2,*, Quanzhong Huang^1,2

, Zailin Huo², Yunwu Xiong^1,2 and Guanhua Huang^1,2

¹ Chinese-Israeli International Center for Research and Training in Agriculture, China Agricultural University, Beijing 100083, China

² Center for Agricultural Water Research, China Agricultural University, Beijing 100083, China

Water 2018, 10(5), 634; https://doi.org/10.3390/w10050634 - 15 May 2018

Cited by 36 | Viewed by 4593

Abstract

Clarifying the role of shallow groundwater systems in eco-hydrological processes is of great significance to agricultural production and ecological sustainability. In this paper, a lumped water balance model was proposed for the GSPAC (groundwater-soil-plant-atmosphere-continuum) system for different land use types under arid, shallow [...] Read more.

Clarifying the role of shallow groundwater systems in eco-hydrological processes is of great significance to agricultural production and ecological sustainability. In this paper, a lumped water balance model was proposed for the GSPAC (groundwater-soil-plant-atmosphere-continuum) system for different land use types under arid, shallow water table conditions. Model application was conducted in an irrigation district (Jiyuan) located in the upper Yellow River basin. A 13-year (2001–2013) water balance calculation was carried out to quantify the water budgets of different land use types. The effects of shallow groundwater on water and salt exchanges among different land use patterns were analyzed. Results indicated the shallow groundwater systems played a significant role in water storage and supply, water and salt redistribution, and the salt accumulation and drainage in Jiyuan. About 36% of the total applied water was first stored in a shallow groundwater system, and then redistributed. After redistribution, 63% of the total diverted water was consumed by cropland evapotranspiration (ET), 20% by natural land ET; the rest was discharged through drainage or groundwater exploitation. Finally, 67% of the introduced salt accumulated in natural land, while the rest was drained away, which helped maintain the productivity of the croplands. Overall, our results have quantitatively revealed the multifaceted roles of shallow groundwater systems, and also suggested the key management concepts for sustaining agroecosystems in arid irrigated areas. Full article

(This article belongs to the Section Water, Agriculture and Aquaculture)

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18 pages, 2086 KiB

Open AccessArticle

Computational Fluid Dynamics for Modeling Gravity Currents in the Presence of Oscillatory Ambient Flow

by Laura Maria Stancanelli^*,†

, Rosaria Ester Musumeci^† and Enrico Foti

¹ Department of Civil Engineering and Architecture, Via Santa Sofia 64, 95125 Catania, Italy

^† These authors contributed equally to this work.

Water 2018, 10(5), 635; https://doi.org/10.3390/w10050635 - 14 May 2018

Cited by 11 | Viewed by 5623

Abstract

Gravity currents generated by lock release are studied in the case of initially quiescent ambient fluid and oscillating ambient fluid (regular surface waves). In particular, the dynamics of the density currents are investigated by means of CFD numerical simulations. The aim is to [...] Read more.

Gravity currents generated by lock release are studied in the case of initially quiescent ambient fluid and oscillating ambient fluid (regular surface waves). In particular, the dynamics of the density currents are investigated by means of CFD numerical simulations. The aim is to evaluate the influence of the ambient fluid velocity field on the observed mixing and turbulent processes. Results of two different turbulence closure models, namely the standard

k - ε

turbulence model and the LES model, are analyzed. Model predictions are validated through comparison with laboratory measurements. Results show that the

k - ε

model is able to catch the main current propagation parameters (e.g., front velocity at the different phases of the evolution of the current, gravity current depth, etc.), but that a LES model provides more realistic insights into the turbulent processes (e.g., formation of interfacial Kelvin–Helmholtz billows, vortex stretching and eventual break up into 3D turbulence). The ambient fluid velocity field strongly influences the dynamics of the gravity currents. In particular, the presence of an oscillatory motion induces a relative increase of mixing at the front (up to 25%) in proximity of the bottom layer, and further upstream, an increase of the mixing process (up to 60%) is observed due to the mass transport generated by waves. The observed mixing phenomena observed are also affected by the ratio between the gravity current velocity

v_{f}

and the horizontal orbital velocity induced by waves

u_{w}

, which has a stronger impact in the wave dominated regime (

v_{f} / u_{w}

< 1). Full article

(This article belongs to the Special Issue Turbulence in River and Maritime Hydraulics)

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18 pages, 3981 KiB

Open AccessFeature PaperArticle

An Investigation on Performance and Structure of Ecological Revetment in a Sub-Tropical Area: A Case Study on Cuatien River, Vinh City, Vietnam

by Van Tai Tang^1,2,3, Dafang Fu^1,2, Tran Ngoc Binh⁴, Eldon R. Rene⁵, Tang Thi Thanh Sang⁶ and Rajendra Prasad Singh^1,2,*

¹ School of Civil Engineering, Southeast University, Nanjing 210096, China

² Southeast University-Monash University Joint Research Centre for Water Sensitive Cities, Nanjing 210096, China

³ Green Processing, Bioremediation and Alternative Energies Research Group, Faculty of Environment and Labour Safety, Ton Duc Thang University, Ho Chi Minh City 700000, Vietnam

⁴ Faculty of Public Health, Vinh Medical University, Vinh City 460000, Vietnam

⁵ Department of Environmental Engineering and Water Technology, IHE-Delft Institute for Water Education, IHE-Delft, 2601 DA Delft, The Netherlands

⁶ Department of Law, Vinh University, Vinh City 461010, Vietnam

Water 2018, 10(5), 636; https://doi.org/10.3390/w10050636 - 14 May 2018

Cited by 17 | Viewed by 7140

Abstract

The current study was performed with an aim to investigate the performance of ecological revetments implemented on the bank of the Cuatien River in Vinh city, Vietnam. Based on the ecological, topographical, and hydrological conditions of the Cuatien River, the gabion and riprap [...] Read more.

The current study was performed with an aim to investigate the performance of ecological revetments implemented on the bank of the Cuatien River in Vinh city, Vietnam. Based on the ecological, topographical, and hydrological conditions of the Cuatien River, the gabion and riprap models were introduced to investigate the effect of ecological revetment on the slope stability and ecological restoration characteristics. The effect of prevailing climatic indicators, such as temperature, precipitation, sunlight hours, and humidity were investigated to ascertain the characteristics of weather conditions on the subtropical area. On the surface soil layer of the gabion and riprap, the nutrient indicators of soil organic matter (SOM) and available nitrogen (AN) increased in the spring, summer, and winter, but decreased in autumn, and available phosphorus (AP) did not show an obvious change in the four seasons. The biomass growth rate of Vetiver grass on the gabion and riprap revetments was found to be the highest during the summer, at 15.11 and 17.32 g/month, respectively. The root system of Vetiver and other native plants could increase the cohesion of soil. After 6 and 12 months, the shear strength of the soil behind the gabion revetment increased by 59.6% and 162.9%, while the shear strength of the soil under the riprap also increased by 115.6% and 239.1%, respectively. The results also indicated that the gabion and riprap revetments could improve the river water purification effect and increase the ecological diversity in the region. In the current study, 26 floral and 9 faunal species were detected in the riprap revetment, whereas 14 floral and 5 faunal species were detected in the gabion revetment, respectively. Through high sequencing technology, the number of bacterial species in the present study was found to be 198, 332, and 351 in the water, gabion, and riprap samples, respectively. Full article

(This article belongs to the Special Issue Sponge Cities: Emerging Approaches, Challenges and Opportunities)

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17 pages, 22963 KiB

Open AccessArticle

Estimation of Future Probable Maximum Precipitation in Korea Using Multiple Regional Climate Models

by Okjeong Lee¹

and Sangdan Kim^2,*

¹ Division of Earth Environmental System Science (Major of Environmental Engineering), Pukyong National University, Busan 48513, Korea

² Department of Environmental Engineering, Pukyong National University, Busan 48513, Korea

Water 2018, 10(5), 637; https://doi.org/10.3390/w10050637 - 15 May 2018

Cited by 18 | Viewed by 3873

Abstract

In this study, future probable maximum precipitations (PMPs) based on future meteorological variables produced from three regional climate models (RCMs) of 50-km spatial resolution provided by Coordinated Regional Climate Downscaling Experiment (CORDEX) are projected. In order to estimate future PMPs, the hydro-meteorological method [...] Read more.

In this study, future probable maximum precipitations (PMPs) based on future meteorological variables produced from three regional climate models (RCMs) of 50-km spatial resolution provided by Coordinated Regional Climate Downscaling Experiment (CORDEX) are projected. In order to estimate future PMPs, the hydro-meteorological method is applied. The key future meteorological variable used to analyze the rate of change of future PMPs is the dew-point temperature. Future 12-h persistence 100-year return period extreme dew-point temperatures obtained from future daily dew-point temperature time series by using the scale-invariance method are applied to estimate future PMPs. As a result of estimating future PMPs using several RCMs and representative concentration pathways (RCPs) scenarios, the spatial distribution of future PMPs is expected to be similar to that of the present, but PMPs tend to increase in the future. In addition, it can be seen that the difference in PMPs estimated from various RCMs and RCP scenarios is getting bigger in the future. Especially after 2070, the difference has increased even more. In the short term, it is proposed to establish climate change adaptation policies with an 18% increase in PMPs, which is the ensemble average in the future year 2050. Full article

(This article belongs to the Section Hydrology)

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23 pages, 5820 KiB

Open AccessArticle

Experimental and Numerical Study of Free-Surface Flows in a Corrugated Pipe

by Francesco Calomino^*, Giancarlo Alfonsi, Roberto Gaudio

, Antonino D’Ippolito

, Agostino Lauria, Ali Tafarojnoruz and Serena Artese

Dipartimento di Ingegneria Civile, Università della Calabria, Via P. Bucci, Cubo 42b, 87036 Rende, Italy

Water 2018, 10(5), 638; https://doi.org/10.3390/w10050638 - 15 May 2018

Cited by 38 | Viewed by 5330

Abstract

A new discharge computational model is proposed on the basis of the integration of the velocity profile across the flow cross-section in an internally corrugated pipe flowing partially full. The model takes into account the velocity profiles in the pressurised pipe to predict [...] Read more.

A new discharge computational model is proposed on the basis of the integration of the velocity profile across the flow cross-section in an internally corrugated pipe flowing partially full. The model takes into account the velocity profiles in the pressurised pipe to predict the flow rate under free-surface flow conditions. The model was evaluated through new laboratory experiments as well as a literature datasets. The results show that flow depth and pipe slope may affect the model accuracy; nevertheless, a prediction error smaller than 20% is expected from the model. Experimental results reveal the influence of the pipe slope and flow depth on the friction factor and the stage-discharge curves: the friction factor may increase with pipe slope, while it reduces as flow depth increases. Hence, a notable change of pipe slope may lead to the variation of the stage-discharge curve. A part of this study deals with numerical simulation of the velocity profiles and the stage-discharge curves. Using the Reynolds-Averaged Navier-Stokes (RANS) equations, numerical solutions were obtained to simulate four experimental tests, obtaining enough accurate results as to velocity profiles and water depths. The results of the simulated flow velocity were used to estimate the flow discharge, confirming the potential of numerical techniques for the prediction of stage-discharge curves. Full article

(This article belongs to the Section Hydraulics and Hydrodynamics)

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12 pages, 2398 KiB

Open AccessArticle

New Screening tool for Obtaining Concentration Statistics of Pollution Generated by Rivers in Estuaries

by Morena Galešić^1,*

, Roko Andričević¹, Vladimir Divić¹

and Robert Šakić Trogrlić²

¹ Faculty of Civil Engineering, Architecture and Geodesy, University of Split, Split 21000, Croatia

² School of Energy, Geoscience, Infrastructure and Environment, Institute for Infrastructure and Environment, Heriot-Watt University, Edinburgh EH14 4AS, UK

Water 2018, 10(5), 639; https://doi.org/10.3390/w10050639 - 15 May 2018

Cited by 2 | Viewed by 4227 | Correction

Abstract

Rivers represent an essential pathway for waterborne transport, and therefore estuaries are critical coastal areas for a pollution hazard that might lead to eutrophication and general water quality deterioration. When addressing these problems, the decision makers and coastal managers often need additional skills [...] Read more.

Rivers represent an essential pathway for waterborne transport, and therefore estuaries are critical coastal areas for a pollution hazard that might lead to eutrophication and general water quality deterioration. When addressing these problems, the decision makers and coastal managers often need additional skills and specialists, so they engage consultants in developing models and providing potential solutions. Different stakeholders’ interests present a challenge in the implementation process of proposed solutions. Nevertheless, if the relevant institutions were presented with a screening tool, enabling them with a certain level of solution ownership, potentially more involvement would occur. There are numerous intertwined physical processes present in the estuary ecosystem, including river discharge, tidal forces, wind-induced stress and water density variations. This research utilizes an analytical model based on ensemble averaging and near-field approximation of the advective-diffusion equation for the case of continuous, steady, conservative solute transport in a stratified, river-dominated estuary. Such an approach significantly reduces the costs and time needed to obtain enough measured data required for common statistical analysis or the need for a more complex numerical model. The developed methodology is implemented into a simple software named CPoRT (Coastal Pollution Risk Tool) within a recently conducted research project funded by European Social Fund. Full article

(This article belongs to the Special Issue Hydrology, Water Resources Management and Protection of the Marine Environment–Selected Papers from the 15th International Conference on Environmental Science And Technology (CEST2017))

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18 pages, 22590 KiB

Open AccessArticle

Daily Evapotranspiration Estimation at the Field Scale: Using the Modified SEBS Model and HJ-1 Data in a Desert-Oasis Area, Northwestern China

by Zhenyan Yi¹, Hongli Zhao¹, Yunzhong Jiang^1,*, Haowen Yan², Yin Cao^1,3, Yanyan Huang¹ and Zhen Hao^1,4

¹ Department of Water Resources, China Institute of Water Resources and Hydropower Research, Beijing 100038, China

² School of Surveying and Mapping Geographic Information, Lanzhou Jiaotong University, Lanzhou 730070, China

³ College of Environmental Science and Engineering, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 200051, China

⁴ School of Hydraulic Engineering, Dalian University of Technology, Dalian 116024, China

Water 2018, 10(5), 640; https://doi.org/10.3390/w10050640 - 15 May 2018

Cited by 11 | Viewed by 5042

Abstract

Accurate continuous daily evapotranspiration (ET) at the field scale is crucial for allocating and managing water resources in irrigation areas, particularly in arid and semi-arid regions. The authors integrated the modified perpendicular drought index (MPDI) as an indicator of water stress into surface [...] Read more.

Accurate continuous daily evapotranspiration (ET) at the field scale is crucial for allocating and managing water resources in irrigation areas, particularly in arid and semi-arid regions. The authors integrated the modified perpendicular drought index (MPDI) as an indicator of water stress into surface energy balance system (SEBS) to improve ET estimation under water-limited conditions. The new approach fed with Chinese satellite HJ-1 (environmental and disaster monitoring and forecasting with a small satellite constellation) images was used to map daily ET on the desert-oasis irrigation fields in the middle of the Heihe River Basin. The outputs, including instantaneous sensible heat flux (H) and daily ET from the MPDI-integrated SEBS and the original SEBS model, were compared with the eddy covariance observations. The results indicate that the MPDI-integrated SEBS significantly improved the surface turbulent fluxes in water-limited regions, especially for sparsely vegetated areas. The new approach only uses one optical satellite data and meteorological data as inputs, providing a considerable operational improvement for ET mapping. Moreover, HJ-1 high-resolution data promised continuous daily ET at the field scale, which helps in understanding the corresponding relationships among field, crop, and water consumption. Such detailed ET information can greatly serve water resources management in the study area as well as other arid and semi-arid regions. Full article

(This article belongs to the Special Issue Applications of Remote Sensing and GIS in Hydrology)

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15 pages, 1410 KiB

Open AccessArticle

Occurrence and Health-Risk Assessment of Trace Metals in Raw and Boiled Drinking Water from Rural Areas of China

by Junhua Wu^1,2,†, Yi Man^3,4,†, Guangyi Sun^3,4,*

and Lihai Shang³

¹ Graduate School of Chinese Academy of Geological Sciences, Beijing 100037, China

² Center of Exploration and Development of Geology and Mineral Resources of Jiangxi Province, Nanchang 330030, China

³ State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry Chinese Academy of Sciences, Guiyang 550081, China

⁴ University of Chinese Academy of Sciences, Beijing 100049, China

^† These authors contributed equally to this work.

Water 2018, 10(5), 641; https://doi.org/10.3390/w10050641 - 16 May 2018

Cited by 27 | Viewed by 5636

Abstract

In order to assess the exposure of rural residents to trace metals via drinking water ingestion, 222 drinking water samples of rural areas from 8 provinces in China were collected and 18 trace metals analyzed by inductively coupled plasma mass spectrometer (ICP-QMS). Based [...] Read more.

In order to assess the exposure of rural residents to trace metals via drinking water ingestion, 222 drinking water samples of rural areas from 8 provinces in China were collected and 18 trace metals analyzed by inductively coupled plasma mass spectrometer (ICP-QMS). Based on metal concentrations, the health-risk assessment such as chronic daily intakes (CDI) and hazard quotient (HQ) were calculated. Results showed that most metals occurred in the drinking water at very low concentrations, indicating a general good quality, while the concentrations of As, Pb and Zn in some samples from Qinghai, Yunnan and Hunan provinces were higher than World Health Organization (WHO) and Chinese guidelines for drinking water. The values of CDI and HQ indicated a negligible health risk for most Chinese rural residents via drinking water. However, high concentrations of As in drinking water from Qinghai province would pose a serious risk to the local inhabitants. More attention and intensive study should be paid to Zn, Pb and As contents. Full article

(This article belongs to the Section Water Quality and Contamination)

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23 pages, 8982 KiB

Open AccessArticle

Evaluation of Multi-Satellite Precipitation Products for Streamflow Simulations: A Case Study for the Han River Basin in the Korean Peninsula, East Asia

by Thom Thi Vu, Li Li and Kyung Soo Jun^*

Graduate School of Water Resources, Sungkyunkwan University, Suwon 16419, Korea

Water 2018, 10(5), 642; https://doi.org/10.3390/w10050642 - 16 May 2018

Cited by 69 | Viewed by 7130

Abstract

The accuracy and sufficiency of precipitation data play a key role in environmental research and hydrological models. They have a significant effect on the simulation results of hydrological models; therefore, reliable hydrological simulation in data-scarce areas is a challenging task. Advanced techniques can [...] Read more.

The accuracy and sufficiency of precipitation data play a key role in environmental research and hydrological models. They have a significant effect on the simulation results of hydrological models; therefore, reliable hydrological simulation in data-scarce areas is a challenging task. Advanced techniques can be utilized to improve the accuracy of satellite-derived rainfall data, which can be used to overcome the problem of data scarcity. Our study aims to (1) assess the accuracy of different satellite precipitation products such as Tropical Rainfall Measuring Mission (TRMM 3B42 V7), Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN), PERSIANN-Climate Data Record (PERSIANN-CDR), and China Meteorological Assimilation Driving Datasets for the SWAT Model (CMADS) by comparing them with gauged rainfall data; and (2) apply them for runoff simulations for the Han River Basin in South Korea using the SWAT model. Based on the statistical measures, that is, the proportion correct (PC), the probability of detection (POD), the frequency bias index (FBI), the index of agreement (IOA), the root-mean-square-error (RMSE), the mean absolute error (MAE), the coefficient of determination (R²), and the bias, the rainfall data of the TRMM and CMADS show a better accuracy than those of PERSIANN and PERSIANN-CDR when compared to rain gauge measurements. The TRMM and CMADS data capture the spatial rainfall patterns in mountainous areas as well. The streamflow simulated by the SWAT model using ground-based rainfall data agrees well with the observed streamflow with an average Nash-Sutcliffe efficiency (NSE) of 0.68. The four satellite rainfall products were used as inputs in the SWAT model for streamflow simulation and the results were compared. The average R², NSE, and percent bias (PBIAS) show that hydrological models using TRMM (R² = 0.54, NSE = 0.49, PBIAS = [−52.70–28.30%]) and CMADS (R² = 0.44, NSE = 0.42, PBIAS = [−29.30–41.80%]) data perform better than those utilizing PERSIANN (R² = 0.29, NSE = 0.13, PBIAS = [38.10–83.20%]) and PERSIANN-CDR (R² = 0.25, NSE = 0.16, PBIAS = [12.70–71.20%]) data. Overall, the results of this study are satisfactory, given that rainfall data obtained from TRMM and CMADS can be used to simulate the streamflow of the Han River Basin with acceptable accuracy. Based on these results, TRMM and CMADS rainfall data play important roles in hydrological simulations and water resource management in the Han River Basin and in other regions with similar climate and topographical characteristics. Full article

(This article belongs to the Special Issue Application of the China Meteorological Assimilation Driving Datasets for the SWAT Model (CMADS) in East Asia)

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21 pages, 2571 KiB

Open AccessArticle

Application of Microbial Technology Used in Bioremediation of Urban Polluted River: A Case Study of Chengnan River, China

by Hong Gao¹

, Yuebo Xie^1,2,*, Sarfraz Hashim³, Alamgir Akhtar Khan³, Xiaolin Wang⁴

and Huiyong Xu¹

¹ College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China

² National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety, Nanjing 210098, China

³ Department of Agricultural Engineering, Muhammad Nawaz Shareeef University of Agriculture, Multan 6000, Pakistan

⁴ School of Water Conservancy and Electric Power, Hebei University of Engineering, Handan 056038, China

Water 2018, 10(5), 643; https://doi.org/10.3390/w10050643 - 16 May 2018

Cited by 46 | Viewed by 11654

Abstract

Contrary to the constraints in time, investment, and management of the traditional technology for waste water treatment, this paper seeks to propose a more advanced, reliable, and affordable new technology to restore urban polluted rivers to pristine quality levels. The paper also presents [...] Read more.

Contrary to the constraints in time, investment, and management of the traditional technology for waste water treatment, this paper seeks to propose a more advanced, reliable, and affordable new technology to restore urban polluted rivers to pristine quality levels. The paper also presents new ideas on the selection and use of microbial agents to improve the efficiency of pollution removal. It presents the successful implementation of microbial technology (MT) on Chengnan River, which was heavily polluted before MT implementation. Without artificial aeration, sediment dredging, or complete sewage interception, we directly sprayed a previously configured HP-RPe-3 Microbial Agent into the water body and sediment. We considered the feasibility of MT for treating polluted urban rivers from the perspective of several water quality indices evaluation methods. After the treatment, the concentration of dissolved oxygen (DO) reached 5.0 mg/L, the removal rates of ammonia nitrogen (NH₃-N) and chemical oxygen demand (COD) reached 20% and 38% respectively, and the average degradation rate of total phosphorus (TP) along river was close to 15%. Also, the Nemerow Index of the river was reduced from 2.7 to 1.9. The Fuzzy Comprehensive Index shows a tendency for improvement from Inferior Grade V to a better grade (approximately Grade III). The color of the river water changed, from black or dark green, to its original color. The results indicate that the bioremediation technology of directly adding microbial agents mainly aimed for the degradation of NH₃-N can preliminarily eliminate the black-odor phenomenon of urban rivers, and improve their water quality. It is expected that the MT application, and the concept of how to select the corresponding microbial agents according to main pollutants, can be widely accepted and applied to similar cases. Full article

(This article belongs to the Section Water Quality and Contamination)

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16 pages, 1914 KiB

Open AccessArticle

Long-Term Monitoring of a Surface Flow Constructed Wetland Treating Agricultural Drainage Water in Northern Italy

by Stevo Lavrnić¹, Ilaria Braschi¹, Stefano Anconelli², Sonia Blasioli¹, Domenico Solimando², Paolo Mannini² and Attilio Toscano^1,*

¹ Department of Agricultural and Food Sciences, Alma Mater Studiorum-University of Bologna, Viale Giuseppe Fanin 40-50, 40127 Bologna, Italy

² Consorzio di Bonifica Canale Emiliano Romagnolo, Via Ernesto Masi 8, 40137 Bologna, Italy

Water 2018, 10(5), 644; https://doi.org/10.3390/w10050644 - 16 May 2018

Cited by 34 | Viewed by 6181

Abstract

Agricultural drainage water that has seeped into tile drainage systems can cause nitrogen and phosphorus pollution of the surface water bodies. Constructed wetlands (CWs) can help mitigate the effects of agricultural non-point sources of pollution and remove different pollutants from tile drainage water. [...] Read more.

Agricultural drainage water that has seeped into tile drainage systems can cause nitrogen and phosphorus pollution of the surface water bodies. Constructed wetlands (CWs) can help mitigate the effects of agricultural non-point sources of pollution and remove different pollutants from tile drainage water. In this study, hydrological and water quality data of a Northern Italian CW that has been treating agricultural drainage water since 2000 were considered to assess its ability to mitigate nitrogen and phosphorus pollution. The effects of such long-term operation on the nutrients and heavy metals that eventually accumulate in CW plants and sediments were also analysed. Since 2003, the CW has received different inflows with different nutrient loads due to several operation modes. However, on average, the outflow load has been 50% lower than the inflow one; thus, it can be said that the system has proved itself to be a viable option for tile drainage water treatment. It was found that the concentration of nitrogen and phosphorus in the plant tissues varied, whereas the nitrogen content of the soil increased more than 2.5 times. Heavy metals were found accumulated in the plant root systems and uniformly distributed throughout a 60 cm soil profile at levels suitable for private and public green areas, according to the Italian law Full article

(This article belongs to the Special Issue Wetlands for the Treatment of Agricultural Drainage Water)

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19 pages, 6614 KiB

Open AccessArticle

Impact of the Storm Sewer Network Complexity on Flood Simulations According to the Stroke Scaling Method

by Qiqi Yang^1,2,3

, Qiang Dai^1,2,3,*, Dawei Han²

, Xuehong Zhu^1,3 and Shuliang Zhang^1,3,*

¹ Key Laboratory of Virtual Geographic Environment, Nanjing Normal University, Ministry of Education, Nanjing 210023, China

² Water and Environmental Management Research Centre, Department of Civil Engineering, University of Bristol, Bristol BS8 1TR, UK

³ Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China

Water 2018, 10(5), 645; https://doi.org/10.3390/w10050645 - 16 May 2018

Cited by 14 | Viewed by 4630

Abstract

For urban watersheds, the storm sewer network provides indispensable data for flood modeling but often needs to be simplified to balance the conflict between the large amount of data and current computing power. The sensitivity of a flood simulation to the data precision [...] Read more.

For urban watersheds, the storm sewer network provides indispensable data for flood modeling but often needs to be simplified to balance the conflict between the large amount of data and current computing power. The sensitivity of a flood simulation to the data precision of a storm sewer network needs to be explored to develop reasonable generalization strategies. In this study, the impact of using the stroke scaling method to generalize a storm sewer network on a flood simulation was analyzed in terms of the total inflow of the outfalls and flood results. The results of the three study basins showed that different complexities of a sewer network did not have a significant effect on the outfall’s total inflow for an area with a single drainage system but did for an area with multiple drainage systems. In addition, serious flooding was mainly distributed at the backbone pipes, which can be identified with the simplified sewer network. Several effective generalization strategies were developed for sewer networks that consider the distribution characteristics of the drainage system and application requirements. This study is theoretically important for better understanding the data sensitivity of flood modeling and simulation and practically important for improving the modeling efficiency and the accuracy of urban flood simulation. Full article

(This article belongs to the Section Urban Water Management)

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17 pages, 4966 KiB

Open AccessArticle

Recognizing the Relationship between Spatial Patterns in Water Quality and Land-Use/Cover Types: A Case Study of the Jinghe Oasis in Xinjiang, China

by Fei Zhang^1,2,3,*, Juan Wang⁴ and Xiaoping Wang^1,2,3

¹ College of Resources and Environment Science, Xinjiang University, Urumqi 830046, China

² Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi 830046, China

³ Key Laboratory of Xinjiang Wisdom City and Environment Modeling, Urumqi 830046, China

⁴ College of Geography and Remote Sensing Science, Beijing Normal University, Beijing 100875, China

Water 2018, 10(5), 646; https://doi.org/10.3390/w10050646 - 16 May 2018

Cited by 29 | Viewed by 4759

Abstract

To understand the relationship between spatial water quality patterns and changes in land-use/cover types in the Jinghe Oasis, 47 water sampling sites measured in May and October 2015 were divided into six cluster layers using the self-organizing map method, which is based on [...] Read more.

To understand the relationship between spatial water quality patterns and changes in land-use/cover types in the Jinghe Oasis, 47 water sampling sites measured in May and October 2015 were divided into six cluster layers using the self-organizing map method, which is based on non-hierarchical k-means classification. The water quality indices included the chemical oxygen demand (COD), biological oxygen demand (BOD), suspended solids (SS), total phosphorus (TP), total nitrogen (TN), ammonia nitrogen (NH₃-N), chromaticity (SD), and turbidity (NUT). Data was also collected on the changes in the farmland, forest–grassland, water body, salinized land, and other land types during the wet and dry seasons. Then, we combined these data with the classification results of the GF-1 remote sensing satellite data obtained in May and October 2015 and analyzed the influences of land-use/cover type on water quality for different layers and seasons. The results indicate that Clusters 1 to 3 included monitoring samples from the wet season (May 2015), whereas Clusters 4 to 6 included monitoring samples from the dry season (October 2015). In general, the COD, SS, NUT, TN, and NH₃-N values were high around the Ganjia Lake Haloxylon natural conservation area in the southern Ebinur Lake region, east of Ebinur Lake, and around the Kuitun River during the wet season. The SD values around these areas were high. Moreover, high BOD and TP values were mainly concentrated around the Ganjia Lake Haloxylon natural conservation area, as well as the Kuitun River, during the dry season. In the discussion on the relationship between the different water quality parameters and land-use/cover type changes, we determined that farmland, forest–grassland, and salinized land significantly influenced the water quality parameters in the Jinghe Oasis. In addition, the influences of various land-use/cover types on the water quality parameters in the research zone during the different seasons exhibited the following descending order of magnitude: farmland → forest–grassland → salinized land → water body → others. Moreover, their influences were lower during the wet season than the dry season. In conclusion, developing research on the relationship between the spatial framework of the water quality in the Jinghe Oasis and land-use/cover type changes is significant for the time sequence distribution of water quality in arid regions from both theoretical and practical perspectives. Full article

(This article belongs to the Section Water Quality and Contamination)

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17 pages, 5266 KiB

Open AccessArticle

Prediction of Typhoon-Induced Flood Flows at Ungauged Catchments Using Simple Regression and Generalized Estimating Equation Approaches

by Hyosang Lee¹, Neil McIntyre², Joungyoun Kim³

, Sunggu Kim¹ and Hojin Lee^1,*

¹ School of Civil Engineering, Chungbuk National University, Cheongju 28644, Korea

² Centre for Water in the Minerals Industry, University of Queensland, Brisbane 4072, Australia

³ Department of Information & Statistics, Chungbuk National University, Cheongju 28644, Korea

Water 2018, 10(5), 647; https://doi.org/10.3390/w10050647 - 16 May 2018

Cited by 5 | Viewed by 3978

Abstract

Typhoons are the main type of natural disaster in Korea, and accurately predicting typhoon-induced flood flows at gauged and ungauged locations remains an important challenge. Flood flows caused by six typhoons since 2002 (typhoons Rusa, Maemi, Nari, Dienmu, Kompasu and Bolaven) are modeled [...] Read more.

Typhoons are the main type of natural disaster in Korea, and accurately predicting typhoon-induced flood flows at gauged and ungauged locations remains an important challenge. Flood flows caused by six typhoons since 2002 (typhoons Rusa, Maemi, Nari, Dienmu, Kompasu and Bolaven) are modeled at the outlets of 24 Geum River catchments using the Probability Distributed Moisture model. The Monte Carlo Analysis Toolbox is applied with the Nash Sutcliffe Efficiency as the criterion for model parameter estimation. Linear regression relationships between the parameters of the Probability Distributed Moisture model and catchment characteristics are developed for the purpose of generalizing the parameter estimates to ungauged locations. These generalized parameter estimates are tested in terms of ability to predict the flood hydrographs over the 24 catchments using a leave-one-out validation approach. We then test the hypothesis that a more complex generalization approach, the Generalized Estimating Equation, which includes properties of the typhoons as well as catchment characteristics as predictors of PDM model parameters, will provide more accurate predictions. The results show that the predictions of Generalized Estimating Equation are comparable to those of the simpler, conventional regression. The simpler approach is therefore recommended for practical applications; however, further refinements of the Generalized Estimating Equation approach may be explored. Full article

(This article belongs to the Section Hydrology)

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14 pages, 2332 KiB

Open AccessArticle

Removal of Pb²⁺ from Water by Synthesized Tannin Resins from Invasive South African Trees

by Bamidele J. Okoli^1,*

, Patience M. Shilowa¹

, Gabriel O. Anyanwu²

and Johannes S. Modise¹

¹ Institute of Chemical and Biotechnology, Vaal University of Technology, Southern Gauteng Science and Technology Park, Private Bag X021, Vanderbijlpark 1911, South Africa

² Department of Biochemistry, Bingham University, Karu P.M.B 005, Nigeria

Water 2018, 10(5), 648; https://doi.org/10.3390/w10050648 - 17 May 2018

Cited by 15 | Viewed by 5218

Abstract

Contamination of water by

{Pb}^{2 +}

and the threat of invasive vegetation affects the quality and quantity of water accessible to all life forms and has become a primary concern to South Africa and the world at large. This paper synthesized, characterized, [...] Read more.

Contamination of water by

{Pb}^{2 +}

and the threat of invasive vegetation affects the quality and quantity of water accessible to all life forms and has become a primary concern to South Africa and the world at large. This paper synthesized, characterized, and evaluated the resins from tannin-rich invasive Acacia species as an environmentally benign

{Pb}^{2 +}

adsorbent. The analysis of the pore volume and surface area of the resins reveals a small pore dimension of 9

\times

10⁻³ cc/g and large surface area (2.31–8.65 m²/g), presenting suitable physical parameters for adsorption of

{Pb}^{2 +}

. Langmuir model offers the best correlation data at pH 6 with maximum monolayer coverage capacity of 189.30, 105.70 and 98.82 mg/g for silver, black and green wattle tannin resins in aqueous solutions, respectively. The kinetic data suitably fits into a pseudo-second-order model, with the Dubinin–Radushkevich adsorption energy (E)

\leq

7.07 KJ/mol and intra-particle diffusion model confirming an associated physisorption process within the bio-sorption system. The thermogravimetric analysis (TGA) and Fourier-transform infrared (FT-IR) data of the resins were informative of the high thermal stability and chelating functionality such as -OH and -NH₂ responsible for the removal of

{Pb}^{2 +}

. All the resins showed good adsorption characteristics while silver wattle tannin resin has the best adsorption capacity compared to black and green wattle tannin resins. This study provides a prototype adsorbent from invasive plants for the removal of

{Pb}^{2 +}

in water. Full article

(This article belongs to the Section Water Quality and Contamination)

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12 pages, 1800 KiB

Open AccessArticle

Potential Impact of In-Situ Oil Shale Exploitation on Aquifer System

by Shuya Hu^1,2,3, Changlai Xiao^1,2,3, Xue Jiang⁴ and Xiujuan Liang^1,2,3,*

¹ Key Laboratory of Groundwater Resources and Environment of Ministry of Education, Jilin University, Changchun 130021, China

² College of Environmental and Resources, Jilin University, Changchun 130021, China

³ National-Local Joint Engineering Laboratory of In-situ Conversion, Drilling and Exploitation Technology for Oil Shale, Changchun 130021, China

⁴ College of Water Resources and Architectural Engineering, The Northeast Agricultural University, Harbin 150030, China

Water 2018, 10(5), 649; https://doi.org/10.3390/w10050649 - 17 May 2018

Cited by 13 | Viewed by 4532

Abstract

The effects of heat on physical and hydraulic properties of oil shale were investigated. The porosity and water absorption of oil shale increased with increasing pyrolysis temperature. The porosity increased by 19.048% and water absorption increased by 0.76% when oil shale was heated [...] Read more.

The effects of heat on physical and hydraulic properties of oil shale were investigated. The porosity and water absorption of oil shale increased with increasing pyrolysis temperature. The porosity increased by 19.048% and water absorption increased by 0.76% when oil shale was heated to 500 °C. Thus, originally impermeable oil shale was converted to a permeable rock formation, facilitating interactions between surrounding groundwater and oil. Heated oil shale was immersed in water, which showed strong alkaline properties. The content of Ca²⁺ remained stable and a slight decrease in SO₄²⁻ content was observed. Hydrocarbon content in the water samples reached maximum concentration within three days. Full article

(This article belongs to the Special Issue Groundwater Contamination and Remediation)

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18 pages, 34662 KiB

Open AccessArticle

Physical Simulation of Strata Failure and Its Impact on Overlying Unconsolidated Aquifer at Various Mining Depths

by Shuyuan Xu¹, Yongbo Zhang^1,*, Hong Shi², Kai Wang¹, Yipeng Geng¹ and Junfeng Chen¹

¹ College of Water Resources Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China

² College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China

Water 2018, 10(5), 650; https://doi.org/10.3390/w10050650 - 17 May 2018

Cited by 16 | Viewed by 4725

Abstract

Underground mining severely lowers the water table and worsens the ecological environment. To determine the mechanism influencing drawdown in unconsolidated aquifers induced by deep mining combined with overburden movement, with a view to environmental protection, physical simulations for three different depths were designed [...] Read more.

Underground mining severely lowers the water table and worsens the ecological environment. To determine the mechanism influencing drawdown in unconsolidated aquifers induced by deep mining combined with overburden movement, with a view to environmental protection, physical simulations for three different depths were designed to investigate and contrast deformation and fracture distribution characteristics at diverse depths after mining. The impacts on overlying unconsolidated aquifers were then analyzed by monitoring overburden movement and ground water level data, and the deformation limit was estimated. Modeling results indicated that coal mining had different impacts on the overlying unconsolidated aquifer via various mechanisms of groundwater level reduction. The aquifer outside the fractured water-conducting zone could be affected by coal mining, and the water tables dropped rapidly. The failure and the deformation features of the aquitard floor were the key to revealing the mechanism of groundwater depletion in deep mining. The effects on aquitard decreased as the distance from the working face increased. A relationship between the strata deformation and the drawdown rate was established; that is, the rate of decline of the groundwater level did not accelerate until the maximum subsidence of the aquitard floor exceeded approximately 0.9 m, or the subsidence-bending area of the aquitard floor exceeded approximately 156 m². Full article

(This article belongs to the Section Hydrology)

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14 pages, 2449 KiB

Open AccessArticle

On Strong Nearshore Wind-Induced Currents in Flow-Through Gulfs: Variations on a Theme by Csanady

by Georgios M. Horsch^1,* and Nikolaos Th. Fourniotis^1,2

¹ Department of Civil Engineering, University of Patras, University Campus, 26500 Patras, Greece

² Department of Civil Engineering, Technological Educational Institute of Western Greece, Megalou Alexandrou 1, 26334 Patras, Greece

Water 2018, 10(5), 652; https://doi.org/10.3390/w10050652 - 17 May 2018

Cited by 4 | Viewed by 3145

Abstract

Csanady’s (1973) model, used to explain the development of strong, wind-induced nearshore currents in long lakes, has been extended to explain the same phenomenon in flow-through semi-enclosed gulfs. As in the original theory, it is predicted that the depth-averaged velocities move with the [...] Read more.

Csanady’s (1973) model, used to explain the development of strong, wind-induced nearshore currents in long lakes, has been extended to explain the same phenomenon in flow-through semi-enclosed gulfs. As in the original theory, it is predicted that the depth-averaged velocities move with the wind in regions shallower than the characteristic depth and upwind in deeper parts of the basin. The characteristic depth in the modified theory, however, is shown to be larger than the characteristic depth of the original theory, which is the basin mean depth, by a parameter λ, which can be calculated using the wind stress, the cross-section area and the volumetric inflow into the gulf. The theory is further used to examine in detail the scaling of the flow and identify the dimensional parameters underlying the formulation of the Csanady model. By expanding in an appropriately-defined inverse, Rossby number, which can be made arbitrarily large for small times, it is shown that under the influence of the Coriolis force, the free surface assumes a characteristic S-like shape and the shorewise volume flux an M-like shape. It is suggested that the shorewise flux might be of interest in environmental applications. The predictions of both variations of the original model of Csanady have been illustrated by numerical simulations, in pertinent idealized geometries, and have been also used to explain salient features of the wind-induced circulation in the Gulf of Patras in Western Greece. Full article

(This article belongs to the Section Hydraulics and Hydrodynamics)

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15 pages, 5683 KiB

Open AccessArticle

Subpixel Surface Water Extraction (SSWE) Using Landsat 8 OLI Data

by Longhai Xiong¹, Ruru Deng^1,*

, Jun Li¹, Xulong Liu²

, Yan Qin¹, Yeheng Liang¹ and Yingfei Liu¹

¹ Guangdong Engineering Research Center of Water Environment Remote Sensing Monitoring, Guangdong Provincial Key Laboratory of Urbanization and Geo-simulation, School of Geography and Planning, Sun Yat-sen University, Guangzhou 510275, China

² Key Laboratory of Guangdong for Utilization of Remote Sensing and Geographical Information System, Guangzhou Institute of Geography, Guangzhou 510070, China

Water 2018, 10(5), 653; https://doi.org/10.3390/w10050653 - 18 May 2018

Cited by 35 | Viewed by 6247

Abstract

Surface water extraction from remote sensing imagery has been a very active research topic in recent years, as this problem is essential for monitoring the environment, ecosystems, climate, and so on. In order to extract surface water accurately, we developed a new subpixel [...] Read more.

Surface water extraction from remote sensing imagery has been a very active research topic in recent years, as this problem is essential for monitoring the environment, ecosystems, climate, and so on. In order to extract surface water accurately, we developed a new subpixel surface water extraction (SSWE) method, which includes three steps. Firstly, a new all bands water index (ABWI) was developed for pure water pixel extraction. Secondly, the mixed water–land pixels were extracted by a morphological dilation operation. Thirdly, the water fractions within the mixed water–land pixels were estimated by local multiple endmember spectral mixture analysis (MESMA). The proposed ABWI and SSWE have been evaluated by using three data sets collected by the Landsat 8 Operational Land Imager (OLI). Results show that the accuracy of ABWI is higher than that of the normalized difference water index (NDWI). According to the obtained surface water maps, the proposed SSWE shows better performance than the automated subpixel water mapping method (ASWM). Specifically, the root-mean-square error (RMSE) obtained by our SSWE for the data sets considered in experiments is 0.117, which is better than that obtained by ASWM (0.143). In conclusion, the SSWE can be used to extract surface water with high accuracy, especially in areas with optically complex aquatic environments. Full article

(This article belongs to the Section Water Resources Management, Policy and Governance)

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11 pages, 794 KiB

Open AccessArticle

Evaluation of the Water Allocation and Delivery Performance of Jiamakou Irrigation Scheme, Shanxi, China

by Yumiao Fan^1,2,3, Zhanyi Gao^1,*, Shaoli Wang^1,3, Haorui Chen^1,3

and Jing Liu¹

¹ State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China

² College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China

³ National Center for Efficient Irrigation Engineering and Technology Research-Beijing, Beijing 10048, China

Water 2018, 10(5), 654; https://doi.org/10.3390/w10050654 - 18 May 2018

Cited by 23 | Viewed by 5344

Abstract

Irrigation performance assessment is an important step in ensuring sustainable agricultural development and improving the capacity of irrigation water management. In this paper, we examined irrigation water management in the Jiamakou Irrigation Scheme in the province of Shanxi (China) using four typical indicators, [...] Read more.

Irrigation performance assessment is an important step in ensuring sustainable agricultural development and improving the capacity of irrigation water management. In this paper, we examined irrigation water management in the Jiamakou Irrigation Scheme in the province of Shanxi (China) using four typical indicators, namely adequacy, efficiency, dependability, and equity. These indicators were calculated both globally and by grouping the data according to different irrigation processes (water allocation and water delivery). Results show that water was poorly allocated, and crop water requirements calculated through the FAO56 Penman-Monteith method was not met timely by scheduled water. They indicate that the overall performance of the scheme was relatively poor, owing to dismal water allocation. Nevertheless, water delivery performance was good, indicating that the scheme was able to deliver adequate and dependable water in an equitable and efficient manner. Our findings suggest that farmers should be trained in allocating irrigation water. The study provides insights into the current behavior of the irrigation scheme and may be used as a base for improvement of irrigation performance. Full article

(This article belongs to the Section Water Resources Management, Policy and Governance)

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16 pages, 3660 KiB

Open AccessArticle

Evaluation of a UAV-Assisted Autonomous Water Sampling

by Cengiz Koparan¹, Ali Bulent Koc^1,*

, Charles V. Privette¹, Calvin B. Sawyer¹

and Julia L. Sharp²

¹ Department of Agricultural Sciences, Clemson University, Clemson, SC 29634-0310, USA

² Department of Statistics, Colorado State University, Fort Collins, CO 80523-1877, USA

Water 2018, 10(5), 655; https://doi.org/10.3390/w10050655 - 18 May 2018

Cited by 72 | Viewed by 13765

Abstract

Water quality assessment programs for the management of water resources require the collection of water samples for physical, chemical, and biological analyses. Lack of personnel, accessibility of water bodies, and time constraints, especially after natural disasters and emergencies, are some of the challenges [...] Read more.

Water quality assessment programs for the management of water resources require the collection of water samples for physical, chemical, and biological analyses. Lack of personnel, accessibility of water bodies, and time constraints, especially after natural disasters and emergencies, are some of the challenges of water sampling. To overcome these challenges, a custom-made thief-style water sampling mechanism was developed and mounted on a multirotor unmanned aerial vehicle (UAV) for autonomous water sampling. The payload capacity and endurance of the UAV were determined using an indoor test station. The UAV was equipped with floatation, and electronic components were coated to prevent water damage in the event of a forced landing or for sample collection. Water samples from a 1.1 ha pond were collected with the developed UAV-assisted water sampling system and traditional manual methods. Dissolved oxygen (DO), electrical conductivity (EC), pH, temperature and chloride measurements were made on samples collected with both UAV-assisted and manual methods and compared. Percent differences between the two sampling methods for DO, EC, pH, and temperature were minimal except for chloride level. Percent differences between the two sampling methods for DO, EC, pH, and temperature measurements were 3.6%, 2.3%, 0.76%, and 0.03%, respectively. Measured chloride levels for the manual and UAV-assisted sampling methods were 3.97 and 5.46 mg/L. UAV-assisted water sampling may prove faster and safer than manual water sampling from large surface waters and from difficult to access water bodies. Full article

(This article belongs to the Section Water Quality and Contamination)

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19 pages, 6031 KiB

Open AccessArticle

Temperature Rise of Seawater Simulation under the Influence of Sediment-Water Heat Exchange

by Yaqiong Guo^1,2 and Jinrong Ma^1,*

¹ State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210024, China

² College of Harbor, Coastal and Offshore Engineering, Hohai University, Nanjing 210098, China

Water 2018, 10(5), 656; https://doi.org/10.3390/w10050656 - 18 May 2018

Cited by 5 | Viewed by 5078

Abstract

Alternating inundation and exposure of large tidal flats regions suggest that differences in thermodynamic properties of sediment and water cause an obvious heat exchange between the tidal sediment and seawater. Due to the influence of these sediment-water heat exchanges, the temperature of seawater [...] Read more.

Alternating inundation and exposure of large tidal flats regions suggest that differences in thermodynamic properties of sediment and water cause an obvious heat exchange between the tidal sediment and seawater. Due to the influence of these sediment-water heat exchanges, the temperature of seawater changes dramatically in coastal areas. To understand and assess the effect of these heat exchanges on seawater temperature, a temperature rise numerical model is adopted to describe the influence of sediment-water heat exchange. The heat exchange is determined mainly by the temperature difference between the sediment and seawater. Thus, a sediment temperature model is developed to predict the temperature of tidal sediment and sediment-water heat flux under the alternating inundated or exposed condition. The surface sediment temperature, as the surface boundary condition of the model, is calculated by the heat balance at the surface, including solar radiation, atmospheric radiation, flat back radiation, latent, and sensible heat fluxes, soil heat flux, and sediment-water heat flux. The collected measured data of sediment temperature are used to verify the accuracy of the sediment temperature model. Based on this, the predicted sediment-water heat flux is provide to the temperature rise model. In the study site, the tidal flat of about 15.8 km² is adopted in the sediment temperature model, and the simulated time is from 11 to 31 May 2017 to meet the collected climate data. The results show that a clear temperature rise water area comes out near the shore considering the heat flux. In warmer season, the maximum water temperature rise is about 2 °C in the local area, and in the envelope area of a 1 °C temperature rise can reach 2.8 km². Certainly, the influence will be stronger after the simulated time moves into the middle of summer with stronger solar radiation. Full article

(This article belongs to the Section Water Quality and Contamination)

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24 pages, 6902 KiB

Open AccessArticle

Evaluation and Bias Correction of Satellite-Based Rainfall Estimates for Modelling Flash Floods over the Mediterranean region: Application to Karpuz River Basin, Turkey

by Mohamed Saber^1,2,*

and Koray K. Yilmaz²

¹ Water Resources Research Center, DPRI, Kyoto University, Goka-sho, Uji City, Kyoto 611-0011, Japan

² Department of Geological Engineering, Middle East Technical University, 06800 Ankara, Turkey

Water 2018, 10(5), 657; https://doi.org/10.3390/w10050657 - 18 May 2018

Cited by 51 | Viewed by 6732

Abstract

This study investigates the utility of satellite-based rainfall estimates in simulating flash floods in Karpuz River Basin, Turkey, characterized by limited rain gauge network. Global Satellite Mapping of Precipitation (GSMaP) product was evaluated with the rain gauge network at daily and monthly time-scales [...] Read more.

This study investigates the utility of satellite-based rainfall estimates in simulating flash floods in Karpuz River Basin, Turkey, characterized by limited rain gauge network. Global Satellite Mapping of Precipitation (GSMaP) product was evaluated with the rain gauge network at daily and monthly time-scales considering seasonality, elevation zones, extreme events and rainfall intensity thresholds. Statistical analysis indicated that GSMaP shows acceptable linear correlation coefficient with rain gauges, however, suffers from significant underestimation bias. Statistical measures exhibited a remarkable deterioration with increasing elevation-following a linear relationship; for example, percent bias was found to increase by a rate of 11.7% with every 400 m interval. A multiplicative bias correction scheme was devised, and Hydrological River Basin Environmental Assessment Model (Hydro-BEAM) was implemented to simulate flash floods driven by the uncorrected/corrected GSMaP data. Analysis of intensity thresholds revealed that appropriate threshold selection is critically important for the bias correction procedure. The hydrological model was calibrated for flash flood events during October–December 2007 and 2012 and validated during October–December, 2009 and 2010. Flash floods simulations were improved by the local bias correction procedure applied to the GSMaP data, but the degree of improvement varied from one period to another. The results of the study indicate that bias factors incorporating multiple variables such as extreme events and elevation variability have the potential to further improve flood simulations. Full article

(This article belongs to the Section Hydrology)

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13 pages, 1089 KiB

Open AccessArticle

Measuring the Value of Farmland-Elevating Engineering in the Reservoir Area of a Key Water Conservancy Project in China

by Jiyong Ding¹

, Wujuan Zhai^1,*

and Leichuang Hu²

¹ Institute of Engineering Management, Hohai University, Nanjing 211100, China

² China Three Gorges International Corporation, Beijing 100033, China

Water 2018, 10(5), 658; https://doi.org/10.3390/w10050658 - 18 May 2018

Cited by 4 | Viewed by 3662

Abstract

With the development and construction of key water conservancy projects, many problems such as population migration in reservoir areas have become increasingly grave in China. The implementation of farmland-elevating engineering has become an effective way to reduce the loss of cultivated land, prevent [...] Read more.

With the development and construction of key water conservancy projects, many problems such as population migration in reservoir areas have become increasingly grave in China. The implementation of farmland-elevating engineering has become an effective way to reduce the loss of cultivated land, prevent soil erosion, and ensure food security and social stability. On the basis of the key technical analysis of farmland-elevating engineering, this paper constructed a value system of farmland-elevating engineering from aspects of social value, ecological value, and economic value and established corresponding measurement models, respectively. Taking a key water conservancy project in Jiangxi province as an example, this paper measures the value of farmland-elevating engineering implemented in this project. The results show that the implementation of farmland-elevating engineering can produce great value. This study aims to provide reliable references for the decision-making regarding farmland-elevating engineering. Full article

(This article belongs to the Section Water, Agriculture and Aquaculture)

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24 pages, 7333 KiB

Open AccessArticle

Satellite-Based, Multi-Indices for Evaluation of Agricultural Droughts in a Highly Dynamic Tropical Catchment, Central Vietnam

by Tien Le Thuy Du^1,2, Duong Du Bui^3,*, Minh Duc Nguyen⁴

and Hyongki Lee¹

¹ Department of Civil and Environmental Engineering, University of Houston, Houston, TX 77004, USA

² Da Nang Institute for Socio-Economic Development, Da Nang, Vietnam

³ National Center for Water Resources Planning and Investigation, Ministry of Natural Resources and Environment, Hanoi, Vietnam

⁴ Institute for Water and Environment, Vietnam Academy for Water Resources, Hanoi, Vietnam

Water 2018, 10(5), 659; https://doi.org/10.3390/w10050659 - 18 May 2018

Cited by 70 | Viewed by 9301

Abstract

Characterization of droughts using satellite-based data and indices in a steep, highly dynamic tropical catchment, like Vu Gia Thu Bon, which is the most important basin in central Vietnam, has remained a challenge for many years. This study examined the six widely used [...] Read more.

Characterization of droughts using satellite-based data and indices in a steep, highly dynamic tropical catchment, like Vu Gia Thu Bon, which is the most important basin in central Vietnam, has remained a challenge for many years. This study examined the six widely used vegetation indices (VIs) to effectively monitor droughts that are based on their sensitivity with precipitation, soil moisture, and their linkage with the impacts on agricultural crop production and forest fires. Six VIs representing the four main groups, including greenness-based VIs (Vegetation Condition Index), water-based VIs (Normalized Difference Water Index, Land Surface Water Index), temperature-based VIs (Temperature Condition Index), and combined VIs (Vegetation Health Index, Normalized Difference Drought Index) were tested using MODIS data from January 2001 to December 2016 with the support of cloud-based Google Earth Engine computational platform. Results showed that droughts happened almost every year, but with different intensity. Vegetation stress was found to be mainly attributed to precipitation in the rice paddy fields and to temperature in the forest areas. Findings revealed that combined vegetation indices were more sensitive drought indicators in the basin, whereas their performance was different by vegetation type. In the rice paddy fields, NDDI was more sensitive to precipitation than other indices; it better captured droughts and their impacts on crop yield. In the forest areas, VHI was more sensitive to temperature, and thus had better performance than other VIs. Accordingly, NDDI and VHI were recommended for monitoring droughts in the agricultural and forest lands, respectively. The findings from this study are crucial to map drought risks and prepare an effective mitigation plan for the basin. Full article

(This article belongs to the Special Issue Applications of Remote Sensing and GIS in Hydrology)

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18 pages, 4381 KiB

Open AccessArticle

Assessment of Key Environmental Factors Influencing the Sedimentation and Aggregation Behavior of Zinc Oxide Nanoparticles in Aquatic Environment

by Rizwan Khan

, Muhammad Ali Inam

, Saba Zam Zam, Du Ri Park

and Ick Tae Yeom^*

Graduate School of Water Resources, Sungkyunkwan University (SKKU) 2066, Suwon 16419, Korea

Water 2018, 10(5), 660; https://doi.org/10.3390/w10050660 - 18 May 2018

Cited by 44 | Viewed by 8004

Abstract

Zinc oxide nanoparticles (ZnO NPs) are among the most widely used engineered nanoparticles (ENPs) in various commercial sectors to achieve both social and economic benefits. The post-use release of these NPs to the environment is inevitable, and may pose threat to the human [...] Read more.

Zinc oxide nanoparticles (ZnO NPs) are among the most widely used engineered nanoparticles (ENPs) in various commercial sectors to achieve both social and economic benefits. The post-use release of these NPs to the environment is inevitable, and may pose threat to the human and eco-system. In the present study, we investigated the influence of single and multiple environmental factors on sedimentation behavior of ZnO NPs. The fractional-factorial method based on Taguchi orthogonal array (OA) L₂₇(3¹³) design matrix was used for systematic investigation on the contribution and significance of multiple factors and their interactions. The result of single-factor showed that the ZnO NPs were unstable at or near pH_zpc, with high electrolyte concentration; however, the adsorption of natural organic matter (NOM) i.e., humic acid, salicylic acid, and citric acid reverses the surface charge and enhanced NP stability. The Fourier transform infrared (FT-IR) analysis confirms the organic capping ligands on the NP surface. Moreover, the matrix result of analysis of variance (ANOVA) showed that electrolyte concentration and type, and NOM concentration were the most significant factors (p < 0.001) in promoting and influencing aggregation, while the interaction between the factors was also found insignificant. In addition, the result of aggregation kinetics and environmental water samples indicated that the mobility of ENPs may vary substantially in an environment with complex and heterogeneous matrices. This study may contribute to better understanding and prediction of the sedimentation behavior and fate of ZnO NPs in aqueous environments, to facilitate their sustainable use in products and process. Full article

(This article belongs to the Section Water Quality and Contamination)

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26 pages, 12769 KiB

Open AccessArticle

Stream Health Evaluation Using a Combined Approach of Multi-Metric Chemical Pollution and Biological Integrity Models

by Usman Atique

and Kwang-Guk An^*

Department of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Korea

Water 2018, 10(5), 661; https://doi.org/10.3390/w10050661 - 18 May 2018

Cited by 46 | Viewed by 7415

Abstract

Bouchung Stream is a large tributary of the Geum River watershed that is simultaneously affected by wastewater treatment plant effluents and agricultural activities in the watershed area. The focal subject was to diagnose the chemical and biological health of the temperate stream by [...] Read more.

Bouchung Stream is a large tributary of the Geum River watershed that is simultaneously affected by wastewater treatment plant effluents and agricultural activities in the watershed area. The focal subject was to diagnose the chemical and biological health of the temperate stream by using a combined approach of the multi-metric water pollution index (WPI) and the index of biological integrity (IBI_KR), using datasets from 2008–2014. Water chemistry analyses indicated seasonal and inter-annual variations mainly linked to the intensity of monsoon rainfall in the watershed, potentially causing the availability of agricultural runoff water. The main events of phosphorus inflow and nitrogen dilutions occurred during July–August. Temporal and spatial heterogeneities were observed and were largely recognizable due to nutrient enrichment and organic matter intensification. Chlorophyll showed weak linear relation to total phosphorus (R² = 0.17) but no relation to total nitrogen (p > 0.05). Fish compositions analyzed as trophic/tolerance guilds in relation to water chemistry showed visible decline and modifications. Average WPI site scores ranged from 33–23, indicating an excellent upstream to fair downstream water quality status. Correspondingly, IBI_KR scores ranged between 38–28 approximating with WPI site classification, as well as both indices showed higher regression relation (R² = 0.90). Fish guild analyses revealed tolerant and omnivore species dominating the downstream, while sensitive and insectivores depleting in approximation with changing water chemistry and was confirmed by the principal component analysis. In addition, the fish guilds meticulously responded to phosphorus inflows. In conclusion, overall stream health and water chemistry analyses indicated continuous chemical and biological degradation influencing the trophic and tolerance fish guilds. Moreover, the combined application approach of WPI and IBI_KR could help in better understanding the chemical and biological mechanisms in rivers and streams. Full article

(This article belongs to the Section Water Quality and Contamination)

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11 pages, 806 KiB

Open AccessArticle

Research on Fuzzy Cooperative Game Model of Allocation of Pollution Discharge Rights

by Xiaoyu Huang^1,2, Xiaohong Chen^1,2,*

and Ping Huang³

¹ Center for Water Resources and Environment, Sun Yat-sen University, Guangzhou 510275, China

² Key Laboratory of Water Cycle and Water Security in Southern China of Guangdong High Education Institute, Sun Yat-sen University, Guangzhou 510275, China

³ School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China

Water 2018, 10(5), 662; https://doi.org/10.3390/w10050662 - 19 May 2018

Cited by 17 | Viewed by 4256

Abstract

The allocation of pollution rights is significant to the economic development of a region, which determines the industrial structure of the region in another way. This study established an allocation model based on fuzzy coalition game theory. Formation of fuzzy coalitions between many [...] Read more.

The allocation of pollution rights is significant to the economic development of a region, which determines the industrial structure of the region in another way. This study established an allocation model based on fuzzy coalition game theory. Formation of fuzzy coalitions between many producers in a region and reallocation of pollution discharge rights in the region through these coalitions was used to increase the total production value of the region while total pollution discharge amount is constant. At the same time, the fuzzy Shapley value method was used to allocate benefits obtained from the cooperation to the participants in various coalitions. This model was validated by its application in the case of three production bases near the Shizi channel in Dongguan city for reallocation of pollution discharge rights. Results showed that this model could increase the coalition benefits of the three production bases in this region, which observed increases of 4.28%, 7.74%, and 13.98%, respectively. Full article

(This article belongs to the Special Issue Water Quality: A Component of the Water-Energy-Food Nexus)

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12 pages, 2724 KiB

Open AccessArticle

TWI Computations and Topographic Analysis of Depression-Dominated Surfaces

by Kendall Grimm, Mohsen Tahmasebi Nasab and Xuefeng Chu^*

Department of Civil and Environmental Engineering (Dept 2470), North Dakota State University, P.O. Box 6050, Fargo, ND 58108-6050, USA

Water 2018, 10(5), 663; https://doi.org/10.3390/w10050663 - 19 May 2018

Cited by 17 | Viewed by 5463

Abstract

The topographic wetness index (TWI) has been widely used for determining the potential of each digital elevation model (DEM) grid to develop a saturated condition, which allows for the investigation of topographic control on the hydrologic response of a watershed. Many studies have [...] Read more.

The topographic wetness index (TWI) has been widely used for determining the potential of each digital elevation model (DEM) grid to develop a saturated condition, which allows for the investigation of topographic control on the hydrologic response of a watershed. Many studies have evaluated TWI, its components, and the impacts of DEM resolution on its computation. However, the majority of the studies are concerned with typical dendritic watersheds, and the effectiveness of TWI computations for depression-dominated areas has been rarely evaluated. The objectives of this study are (1) to develop a modified TWI computation procedure for depression-dominated areas, (2) to examine the differences between the new and existing TWI computation procedures using different DEMs, and (3) to assess the impact of DEM resolution on the new TWI procedure. In particular, a bathymetry survey was conducted for a study area in the Prairie Pothole Region (PPR), and the DEM representing the actual surface topography was created. The statistical analyses of TWI highlighted a two-hump pattern for the depression-dominated surface, whereas a one-hump pattern was observed for the dendritic surface. It was observed that depressional DEM grids accounted for higher values of TWI than other grids. It was demonstrated that a filled DEM led to misleading quantity and distribution of TWI for depression-dominated landscapes. The modified TWI computation procedure proposed in this study can also be applied to other depression-dominated areas. Full article

(This article belongs to the Section Hydrology)

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17 pages, 19114 KiB

Open AccessArticle

The Water–Energy–Food Nexus: A Fuzzy-Cognitive Mapping Approach to Support Nexus-Compliant Policies in Andalusia (Spain)

by Pilar Martinez^*

, Maria Blanco

and Bente Castro-Campos

Department of Agricultural Economics, Universidad Politécnica de Madrid, ETSIAAB, Avda. Puerta Hierro 2, 28040 Madrid, Spain

Water 2018, 10(5), 664; https://doi.org/10.3390/w10050664 - 19 May 2018

Cited by 64 | Viewed by 11377

Abstract

Water, energy and food are essential resources for economic development and social well-being. Framing integrated policies that improve their efficient use requires understanding the interdependencies in the water–energy–food (WEF) nexus. Stakeholder involvement in this process is crucial to represent multiple perspectives, ensure political [...] Read more.

Water, energy and food are essential resources for economic development and social well-being. Framing integrated policies that improve their efficient use requires understanding the interdependencies in the water–energy–food (WEF) nexus. Stakeholder involvement in this process is crucial to represent multiple perspectives, ensure political legitimacy and promote dialogue. In this research, we develop and apply a participatory modelling approach to identify the main interlinkages within the WEF nexus in Andalusia, as a starting point to developing a system dynamic model at a later stage. The application of fuzzy cognitive mapping enabled us to gain knowledge on the WEF nexus according to opinions from 14 decision-makers, as well as contributing to raising awareness and building consensus among stakeholders. Results show that climate change and water availability are key drivers in the WEF nexus in Andalusia. Other variables with significant interlinkages within the WEF nexus are food production, irrigated agriculture, energy cost, socio-economic factors, irrigation water use, environmental conservation, and farm performance indicators. The scenario analysis reveals the interdependencies among nexus sectors and the existence of unanticipated effects when changing variables in the system, which need to be considered to design integrated policies. Full article

(This article belongs to the Special Issue Innovation Issues in Water, Agriculture and Food)

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16 pages, 2668 KiB

Open AccessArticle

Simulation of Soil Water Content in Mediterranean Ecosystems by Biogeochemical and Remote Sensing Models

by Piero Battista^1,*

, Marta Chiesi¹

, Luca Fibbi¹

, Lorenzo Gardin¹, Bernardo Rapi¹, Stefano Romanelli², Maurizio Romani¹

, Francesco Sabatini¹, Elena Salerni³, Claudia Perini³ and Fabio Maselli¹

¹ IBIMET-CNR, 50019 Sesto Fiorentino (FI), Italy

² LaMMA Consortium, 50019 Sesto Fiorentino (FI), Italy

³ Department of Life Sciences, University of Siena, 53100 Siena, Italy

Water 2018, 10(5), 665; https://doi.org/10.3390/w10050665 - 19 May 2018

Cited by 10 | Viewed by 4993

Abstract

The current study assesses the potential of two modeling approaches to simulate the daily site water budget in Mediterranean ecosystems. Both models utilize a simplified one-bucket approach but are fed with different drivers. The first model, BIOME-BGC, simulates all main biogeochemical fluxes based [...] Read more.

The current study assesses the potential of two modeling approaches to simulate the daily site water budget in Mediterranean ecosystems. Both models utilize a simplified one-bucket approach but are fed with different drivers. The first model, BIOME-BGC, simulates all main biogeochemical fluxes based on conventional meteorological and ancillary data, while the second uses evapotranspiration estimates derived from the combination of meteorological data and satellite normalized difference vegetation index (NDVI) images. The two models were tested for three Italian sites which are characterized by different vegetation types and ecoclimatic conditions: (i) low mountain coniferous forest; (ii) hilly deciduous forest; (iii) urban grassland. The soil water balance simulated by the two models was evaluated through comparison with daily measurements of soil water content (SWC) taken during a growing season. Satisfactory results were obtained in all cases by both approaches; the SWC estimates are significantly correlated with the measurements (correlation coefficient, r, higher than 0.74), and the mean errors are lower than 0.079 cm³ cm⁻³. The second model, however, generally shows a higher accuracy, which is dependent on the quality of the NDVI data utilized (r higher than 0.79 and errors lower than 0.059 cm³ cm⁻³). The study therefore provides useful indications for the application of these and similar simulation methods in different environmental situations. Full article

(This article belongs to the Special Issue Monitoring and Predicting Soil Moisture and Drought Conditions)

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23 pages, 20030 KiB

Open AccessArticle

Simulation of Crop Growth and Water-Saving Irrigation Scenarios for Lettuce: A Monsoon-Climate Case Study in Kampong Chhnang, Cambodia

by Pinnara Ket^1,2,*

, Sarah Garré³

, Chantha Oeurng¹, Lyda Hok⁴ and Aurore Degré²

¹ Faculty of Hydrology and Water Resources Engineering, Institute of Technology of Cambodia, Russian Federation Bd, P.O. Box 86, Phnom Penh 12156, Cambodia

² BIOSE, Gembloux Agro-Bio Tech, Liège University, Passage des Déportés 2, Gembloux 5030, Belgium

³ TERRA, Gembloux Agro-Bio Tech, Liège University, Passage des Déportés 2, Gembloux 5030, Belgium

⁴ Department of Soil Science, Faculty of Agronomy, Royal University of Agriculture, P.O. Box 2696, Phnom Penh 12401, Cambodia

Water 2018, 10(5), 666; https://doi.org/10.3390/w10050666 - 21 May 2018

Cited by 14 | Viewed by 7705

Abstract

Setting up water-saving irrigation strategies is a major challenge farmers face, in order to adapt to climate change and to improve water-use efficiency in crop productions. Currently, the production of vegetables, such as lettuce, poses a greater challenge in managing effective water irrigation, [...] Read more.

Setting up water-saving irrigation strategies is a major challenge farmers face, in order to adapt to climate change and to improve water-use efficiency in crop productions. Currently, the production of vegetables, such as lettuce, poses a greater challenge in managing effective water irrigation, due to their sensitivity to water shortage. Crop growth models, such as AquaCrop, play an important role in exploring and providing effective irrigation strategies under various environmental conditions. The objectives of this study were (i) to parameterise the AquaCrop model for lettuce (Lactuca sativa var. crispa L.) using data from farmers’ fields in Cambodia, and (ii) to assess the impact of two distinct full and deficit irrigation scenarios in silico, using AquaCrop, under two contrasting soil types in the Cambodian climate. Field observations of biomass and canopy cover during the growing season of 2017 were used to adjust the crop growth parameters of the model. The results confirmed the ability of AquaCrop to correctly simulate lettuce growth. The irrigation scenario analysis suggested that deficit irrigation is a “silver bullet” water saving strategy that can save 20–60% of water compared to full irrigation scenarios in the conditions of this study. Full article

(This article belongs to the Special Issue Water Management for Sustainable Food Production)

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13 pages, 1853 KiB

Open AccessArticle

Performance of Two Advanced Rainwater Harvesting Systems in Washington DC

by Andrea Braga^1,*

, Hayley O’Grady¹, Turgay Dabak² and Cecilia Lane³

¹ Geosyntec Consultants, Inc., 1330 Beacon Street, Suite 317, Brookline, MA 02446, USA

² Geosyntec Consultants, Inc., 1101 Connecticut Avenue NW, Suite 450, Washington, DC 20036, USA

³ Government of the District of Columbia, Department of Energy & Environment, Watershed Protection Division, 1200 First Street, NE 5th Floor, Washington, DC 20002, USA

Water 2018, 10(5), 667; https://doi.org/10.3390/w10050667 - 22 May 2018

Cited by 16 | Viewed by 6555

Abstract

Combined sewer overflows (CSOs) are a concern for many cities managing stormwater through combined sewer systems, including the District of Columbia (DC). Advanced rainwater harvesting (ARH) is an innovative approach to managing stormwater and has the potential to minimize CSOs and maximize water [...] Read more.

Combined sewer overflows (CSOs) are a concern for many cities managing stormwater through combined sewer systems, including the District of Columbia (DC). Advanced rainwater harvesting (ARH) is an innovative approach to managing stormwater and has the potential to minimize CSOs and maximize water conservation. ARH systems use continuous monitoring and adaptive control (CMAC) technology to store or release water from a rainwater harvesting cistern. This study assessed the efficacy of ARH systems to mitigate wet weather discharges at two firehouses in DC. Continuous monitoring data was collected over a period of three years for the systems that were installed in 2012. The collected data indicates that the systems were effective at mitigating wet weather discharges, with average event harvesting rates greater than 95%. These results suggest that if implemented on a larger scale, ARH systems would be a valuable tool in effectively managing stormwater. Full article

(This article belongs to the Special Issue Technologies and Interventions to Support Sustainable Urban Water Management)

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16 pages, 6147 KiB

Open AccessFeature PaperArticle

Alaska Snowpack Response to Climate Change: Statewide Snowfall Equivalent and Snowpack Water Scenarios

by Jeremy S. Littell^1,*

, Stephanie A. McAfee² and Gregory D. Hayward³

¹ U.S. Geological Survey, DOI Alaska Climate Adaptation Science Center, Anchorage, AK 99508, USA

² Department of Geography, University of Nevada, Reno, NV 89557, USA

³ US Forest Service, Alaska Region, Washington, DC 20024, USA

Water 2018, 10(5), 668; https://doi.org/10.3390/w10050668 - 22 May 2018

Cited by 50 | Viewed by 10084

Abstract

Climatically driven changes in snow characteristics (snowfall, snowpack, and snowmelt) will affect hydrologic and ecological systems in Alaska over the coming century, yet there exist no projections of downscaled future snow pack metrics for the state of Alaska. We updated historical and projected [...] Read more.

Climatically driven changes in snow characteristics (snowfall, snowpack, and snowmelt) will affect hydrologic and ecological systems in Alaska over the coming century, yet there exist no projections of downscaled future snow pack metrics for the state of Alaska. We updated historical and projected snow day fraction (PSF, the fraction of days with precipitation falling as snow) from McAfee et al. We developed modeled snowfall equivalent (SFE) derived from the product of snow-day fraction (PSF) and existing gridded precipitation for Alaska from Scenarios Network for Alaska and Arctic Planning (SNAP). We validated the assumption that modeled SFE approximates historical decadally averaged snow water equivalent (SWE) observations from snowcourse and Snow Telemetry (SNOTEL) sites. We present analyses of future downscaled PSF and two new products, October–March SFE and ratio of snow fall equivalent to precipitation (SFE:P) based on bias-corrected statistically downscaled projections of Coupled Model Intercomparison Project 5 (CMIP5) Global Climate Model (GCM) temperature and precipitation for the state of Alaska. We analyzed mid-century (2040–2069) and late-century (2070–2099) changes in PSF, SFE, and SFE:P relative to historical (1970–1999) mean temperature and present results for Alaska climate divisions and 12-digit Hydrologic Unit Code (HUC12) watersheds. Overall, estimated historical the SFE is reasonably well related to the observed SWE, with correlations over 0.75 in all decades, and correlations exceeding 0.9 in the 1960s and 1970s. In absolute terms, SFE is generally biased low compared to the observed SWE. PSF and SFE:P decrease universally across Alaska under both Representative Concentration Pathway (RCP) 4.5 and RCP 8.5 emissions scenarios, with the smallest changes for RCP 4.5 in 2040–2069 and the largest for RCP 8.5 in 2070–2099. The timing and magnitude of maximum decreases in PSF vary considerably with regional average temperature, with the largest changes in months at the beginning and end of the snow season. Mean SFE changes vary widely among climate divisions, ranging from decreases between −17 and −58% for late twenty-first century in southeast, southcentral, west coast and southwest Alaska to increases up to 21% on the North Slope. SFE increases most at highest elevations and latitudes and decreases most in coastal southern Alaska. SFE:P ratios indicate a broad switch from snow-dominated to transitional annual hydrology across most of southern Alaska by mid-century, and from transitional to rain-dominated watersheds in low elevation parts of southeast Alaska by the late twenty-first century. Full article

(This article belongs to the Special Issue Effects of Climate Change on the Hydrology and Water Quality of Snow-Dominated Mountainous Environments)

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17 pages, 4353 KiB

Open AccessArticle

Assessing the Influence of the Three Gorges Dam on Hydrological Drought Using GRACE Data

by Fupeng Li¹, Zhengtao Wang¹, Nengfang Chao^2,* and Qingyi Song³

¹ School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, China

² College of Marine Science and Technology, China University of Geosciences, Wuhan 430074, China

³ Faculty of Science, University of Alberta, Edmonton, AB T6G 2R3, Canada

Water 2018, 10(5), 669; https://doi.org/10.3390/w10050669 - 22 May 2018

Cited by 28 | Viewed by 6447

Abstract

With worldwide economic and social development, more dams are being constructed to meet the increasing demand for hydropower, which may considerably influence hydrological drought. Here, an index named the “Dam Influence Index” (DII) is proposed to assess the influence of the Three Gorges [...] Read more.

With worldwide economic and social development, more dams are being constructed to meet the increasing demand for hydropower, which may considerably influence hydrological drought. Here, an index named the “Dam Influence Index” (DII) is proposed to assess the influence of the Three Gorges Dam (TGD) on hydrological drought in the Yangtze River Basin (YRB) in China. First, the total terrestrial water storage (TTWS) is derived from Gravity Recovery and Climate Experiment data. Then, the natural-driven terrestrial water storage (NTWS) is predicted from the soil moisture, precipitation, and temperature data based on an artificial neural network model. Finally, the DII is derived using the empirical (Kaplan-Meier) cumulative distribution function of the differences between the TTWS and the NTWS. The DIIs of the three sub-basins in the YRB were 1.38, −4.66, and −7.32 between 2003 and 2008, which indicated an increase in TTWS in the upper sub-basin and a reduction in the middle and lower sub-basins. According to the results, we concluded that impoundments of the TGD between 2003 and 2008 slightly alleviated the hydrological drought in the upper sub-basin and significantly aggravated the hydrological drought in the middle and lower sub-basins, which is consistent with the Palmer Drought Severity Index. This study provides a new perspective for estimating the effects of large-scale human activities on hydrological drought and a scientific decision-making basis for the managing water resources over the operation of the TGD. Full article

(This article belongs to the Special Issue Climate Variability and Climate Change Impacts on Land Surface, Hydrological Processes and Water Management)

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Review

Jump to: Editorial, Research, Other

21 pages, 2046 KiB

Open AccessReview

Central Asia’s Ili River Ecosystem as a Wicked Problem: Unraveling Complex Interrelationships at the Interface of Water, Energy, and Food

by Steven G. Pueppke^1,2,3,*

, Sabir T. Nurtazin⁴, Norman A. Graham^2,5 and Jiaguo Qi³

¹ Department of Plant, Soil, and Microbial Sciences, Michigan State University, 1066 Bogue Street, East Lansing, MI 48824, USA

² Center for European, Russian, and Eurasian Studies, Michigan State University, 427 North Shaw Lane, East Lansing, MI 48824, USA

³ Center for Global Change and Earth Observations, Michigan State University, 1405 South Harrison Road, East Lansing, MI 48824, USA

⁴ Faculty of Biology and Biotechnology, Al-Farabi Kazakh National University, 71 Al-Farabi Avenue, 050040 Almaty, Kazakhstan

⁵ James Madison College, Michigan State University, 842 Chestnut Road, East Lansing, MI 48824, USA

Water 2018, 10(5), 541; https://doi.org/10.3390/w10050541 - 24 Apr 2018

Cited by 37 | Viewed by 10142

Abstract

The Ili River originates in the mountains of Xinjiang, China, and flows across an increasingly arid landscape before terminating in Kazakhstan’s Lake Balkhash, which has no outlet to the ocean. The river has been extensively impounded and diverted over the past half century [...] Read more.

The Ili River originates in the mountains of Xinjiang, China, and flows across an increasingly arid landscape before terminating in Kazakhstan’s Lake Balkhash, which has no outlet to the ocean. The river has been extensively impounded and diverted over the past half century to produce hydroelectric power and food on irrigated land. Water withdrawals are increasing to the extent that they are beginning to threaten the ecosystem, just as it is becoming stressed by altered inflows as glaciers retreat and disappear. If the Ili River ecosystem is to be preserved, it is crucial that we thoroughly understand the spatial and temporal nuances of the interrelationships between water, energy, and food—and the vulnerability of these components to climate change. The ecosystem has all of the characteristics of a classically-defined “wicked problem”, and so it warrants treatment as a complex and dynamic challenge subject to changing assumptions, unexpected consequences, and strong social and economic overtones. Research should thus focus not just on new knowledge about the water, energy, or food component, but on advancing our understanding of the ecosystem as a whole. This will require the participation of interdisciplinary teams of researchers with both tacit and specialized knowledge. Full article

(This article belongs to the Special Issue Water-Energy-Food Nexus in Asia, with Focus on the Mekong Region)

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20 pages, 1524 KiB

Open AccessReview

Value-Added Products Derived from Waste Activated Sludge: A Biorefinery Perspective

by Wei Zhang^1,2,*

, Juan Pablo Alvarez-Gaitan³, Wafa Dastyar⁴, Christopher P. Saint¹, Ming Zhao⁴ and Michael D. Short^1,5,*

¹ School of Natural and Built Environments, University of South Australia, Mawson Lakes, SA 5095, Australia

² Systems and Process Engineering Centre, College of Engineering, Swansea University, Bay Campus, Swansea SA1 8EN, UK

³ UNSW Water Research Centre, School of Civil and Environmental Engineering, The University of New South Wales, Sydney, NSW 2052, Australia

⁴ School of Environment, Tsinghua University, Beijing 100084, China

⁵ Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia

Water 2018, 10(5), 545; https://doi.org/10.3390/w10050545 - 25 Apr 2018

Cited by 52 | Viewed by 9801

Abstract

Substantial research has been carried out on sustainable waste activated sludge (WAS) management in the last decade. In addition to the traditional approach to reduce its production volume, considering WAS as a feedstock to produce bio-products such as amino acids, proteins, short chain [...] Read more.

Substantial research has been carried out on sustainable waste activated sludge (WAS) management in the last decade. In addition to the traditional approach to reduce its production volume, considering WAS as a feedstock to produce bio-products such as amino acids, proteins, short chain fatty acids, enzymes, bio-pesticides, bio-plastics, bio-flocculants and bio-surfactants represents a key component in the transformation of wastewater treatment plants into biorefineries. The quality of these bio-products is a key factor with respect to the feasibility of non-conventional WAS-based production processes. This review provides a critical assessment of the production process routes of a wide range of value-added products from WAS, their current limitations, and recommendations for future research to help promote more sustainable management of this under-utilised and ever-growing waste stream. Full article

(This article belongs to the Section Wastewater Treatment and Reuse)

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18 pages, 2182 KiB

Open AccessReview

The Water-Energy-Food Nexus: Climate Risks and Opportunities in Southern Africa

by Luxon Nhamo^1,*

, Bekithemba Ndlela², Charles Nhemachena¹

, Tafadzwanashe Mabhaudhi³

, Sylvester Mpandeli⁴ and Greenwell Matchaya¹

¹ International Water Management Institute (IWMI-SA), 141 Cresswell St, Weavind Park, Silverton, Pretoria 0184, South Africa

² College of Agriculture and Environmental Sciences (CAES), University of South Africa (UNISA), Preller Street, Muckleneuk Ridge, Pretoria 0003, South Africa

³ School of Agricultural, Earth and Environmental Sciences, University of KwaZulu-Natal, P. Bag X01, Scottsville, Pietermaritzburg 3209, South Africa

⁴ Water Research Commission of South Africa, 4 Daventry Street, Lynnwood Manor, Pretoria 0081, South Africa

Water 2018, 10(5), 567; https://doi.org/10.3390/w10050567 - 27 Apr 2018

Cited by 164 | Viewed by 16511

Abstract

The discourse on the need for water, energy, and food security has dominated the development agenda of southern African countries, centred on improving livelihoods, building resilience, and regional integration. About 60% of the population in the Southern African Development Community (SADC) live in [...] Read more.

The discourse on the need for water, energy, and food security has dominated the development agenda of southern African countries, centred on improving livelihoods, building resilience, and regional integration. About 60% of the population in the Southern African Development Community (SADC) live in rural areas relying mainly on rainfed agriculture, lacking access to clean water and energy, yet the region is endowed with vast natural resources. The water-energy-food (WEF) nexus is a conceptual framework that presents opportunities for greater resource coordination, management, and policy convergence across sectors. This is particularly relevant in the SADC region as resources are transboundary and supports efforts linked to regional integration and inclusive socio-economic development and security. We conducted an appraisal of WEF-related policies and institutions in SADC and identified linkages among them. The present ‘silo’ approach in resource management and allocation, often conducted at the national level, contributes to the region’s failure to meet its development targets, exacerbating its vulnerabilities. The lack of coordination of WEF nexus synergies and trade-offs in planning often threatens the sustainability of development initiatives. We highlighted the importance of the WEF nexus to sustainably address the sectoral coordination of resources through harmonised institutions and policies, as well as setting targets and indicators to direct and monitor nexus developments. We illustrate the significance of the nexus in promoting inclusive development and transforming vulnerable communities into resilient societies. The study recommends a set of integrated assessment models to monitor and evaluate the implementation of WEF nexus targets. Going forward, we propose the adoption of a regional WEF nexus framework. Full article

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18 pages, 770 KiB

Open AccessReview

An Overview of Hydropower Reservoirs in Brazil: Current Situation, Future Perspectives and Impacts of Climate Change

by Viviane De Souza Dias¹, Marta Pereira da Luz^2,*

, Gabriela M. Medero³ and Diego Tarley Ferreira Nascimento⁴

¹ Industrial and Systems Engineering Postgraduate Program-MEPROS, Pontifical Catholic University of Goiás, Av. Universitária 1.440, Setor Universitário, Goiânia CEP 74605-010, Goiás, Brazil

² Eletrobras Furnas, Industrial and Systems Engineering Postgraduate Program-MEPROS, Pontifical Catholic University of Goiás, BR153, km 510, Zona Rural, Aparecida de Goiânia CEP 74923-650, Goiás, Brazil

³ School of Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, Edinburgh EH14 4AS, UK

⁴ Geography, Teacher and Humanities Training School, Pontifical Catholic University of Goiás, Av. Universitária 1.440, Setor Universitário, Goiânia CEP 74605-010, Goiás, Brazil

Water 2018, 10(5), 592; https://doi.org/10.3390/w10050592 - 3 May 2018

Cited by 86 | Viewed by 19162

Abstract

Global climate change, related to the greenhouse gases emission, impacts hydroelectric power generation mainly due to the increase in air temperature and changes in the precipitation patterns. As a consequence, it affects basin evapotranspiration process, runoff, sediment transport as well as evaporation of [...] Read more.

Global climate change, related to the greenhouse gases emission, impacts hydroelectric power generation mainly due to the increase in air temperature and changes in the precipitation patterns. As a consequence, it affects basin evapotranspiration process, runoff, sediment transport as well as evaporation of reservoirs. This study analysed the current and future Brazilian context of hydroelectric reservoirs and investigated the potential impacts of climate change on hydropower generation and possible mitigation adjustments, giving relevant examples from around the world. Moreover, it is key to consider other factors that influence the availability of water resources such as: (a) upstream development of reservoirs, mainly the development of agricultural systems, which can contribute to increased water demand; (b) changes in land use, which can have an impact on soil degradation and sediment transport. Hydroelectric dams are a possible alternative to mitigate the impacts of climate change considering that those impacts could generate the need of adaptive actions. The assessment of climate change impacts’ projections anticipates possible future scenarios and can assist in strategic planning together with the definition of adaptive operational policies. Full article

(This article belongs to the Section Water Resources Management, Policy and Governance)

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23 pages, 435 KiB

Open AccessReview

Progress in Understanding the Mechanism of Cr^VI Removal in Fe⁰-Based Filtration Systems

by Marius Gheju

Faculty of Industrial Chemistry and Environmental Engineering, Politehnica University Timisoara, Bd. V. Parvan Nr. 6, Timisoara 300223, Romania

Water 2018, 10(5), 651; https://doi.org/10.3390/w10050651 - 17 May 2018

Cited by 54 | Viewed by 5382

Abstract

Hexavalent chromium (Cr^VI) compounds are used in a variety of industrial applications and, as a result, large quantities of Cr^VI have been released into the environment due to inadequate precautionary measures or accidental releases. Cr^VI is highly toxic to [...] Read more.

Hexavalent chromium (Cr^VI) compounds are used in a variety of industrial applications and, as a result, large quantities of Cr^VI have been released into the environment due to inadequate precautionary measures or accidental releases. Cr^VI is highly toxic to most living organisms and a known human carcinogen by inhalation route of exposure. Another major issue of concern about Cr^VI compounds is their high mobility, which easily leads to contamination of surface waters, soil, and ground waters. In recent years, attention has been focused on the use of metallic iron (Fe⁰) for the abatement of Cr^VI polluted waters. Despite a great deal of research, the mechanisms behind the efficient aqueous Cr^VI removal in the presence of Fe⁰ (Fe⁰/H₂O systems) remain deeply controversial. The introduction of the Fe⁰-based filtration technology, at the beginning of 1990s, was coupled with the broad consensus that direct reduction of Cr^VI by Fe⁰ was followed by co-precipitation of resulted cations (Cr^III, Fe^III). This view is still the dominant removal mechanism (reductive-precipitation mechanism) within the Fe⁰ remediation industry. An overview on the literature on the Cr geochemistry suggests that the reductive-precipitation theory should never have been adopted. Moreover, recent investigations recalling that a Fe⁰/H₂O system is an ion-selective one in which electrostatic interactions are of primordial importance is generally overlooked. The present work critically reviews existing knowledge on the Fe⁰/Cr^VI/H₂O and Cr^VI/H₂O systems, and clearly demonstrates that direct reduction with Fe⁰ followed by precipitation is not acceptable, under environmental relevant conditions, as the sole/main mechanism of Cr^VI removal in the presence of Fe⁰. Full article

(This article belongs to the Special Issue Filters in Drinking Water Treatment)

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14 pages, 1135 KiB

Open AccessCase Report

Application of Stable Isotope Tracer to Study Runoff Generation during Different Types of Rainfall Events

by Jianfeng Gou^1,2, Simin Qu^1,2

, Peng Shi^1,2,*, Dachen Li^1,2, Xueqiu Chen^1,2, Yifan Wang^1,2, Shuai Shan^1,2 and Wei Si¹

¹ College of Water Resources and Hydrology, Hohai University, Nanjing 210098, China

² State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China

Water 2018, 10(5), 538; https://doi.org/10.3390/w10050538 - 24 Apr 2018

Cited by 11 | Viewed by 4142

Abstract

The main purpose of this study is to explore the runoff generation mechanism and isotopic variation of precipitation during typhoon and plum rain events in the mountainous region mainly covered with bamboo in southeastern China. The isotopic value of precipitation in plum rain [...] Read more.

The main purpose of this study is to explore the runoff generation mechanism and isotopic variation of precipitation during typhoon and plum rain events in the mountainous region mainly covered with bamboo in southeastern China. The isotopic value of precipitation in plum rain events is more depleted than that of precipitation in typhoon events and has a larger range of d-excess. Typhoon events are affected by frequent temperate and tropical cyclones, the ocean evaporationis expected to be very intenseand marine air parcels move very quickly. As for plum rain events, marine air parcel moves slowly due to the blocking effect of the cold front and air moisture evaporated from the continent plays a significant role in the isotope of precipitation depletion process. The difference of stable isotope values in various water sources allows the two-component hydrological separation to quantify the contribution of the event and pre-event water. The results indicate that the pre-event water accounts for at least 60% of the discharge and the difference in proportion of pre-event water between different types of rain events suggests that the initial state of watershed, rainfall intensity and macropore flow are major control factors of the runoff production mechanism. Full article

(This article belongs to the Section Hydrology)

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16 pages, 5086 KiB

Open AccessCase Report

A Case Study for the Application of an Operational Two-Dimensional Real-Time Flooding Forecasting System and Smart Water Level Gauges on Roads in Tainan City, Taiwan

by Che-Hao Chang¹, Ming-Ko Chung¹, Song-Yue Yang^2,*

, Chih-Tsung Hsu³ and Shiang-Jen Wu³

¹ Department of Civil Engineering, National Taipei University of Technology, Taipei 10608, Taiwan

² Water Resources Planning Institute, Water Resources Agency, Ministry of Economic Affairs, Taichung 41350, Taiwan

³ National Center for High-Performance Computing, National Applied Research Laboratories, Hsinchu 30076, Taiwan

Water 2018, 10(5), 574; https://doi.org/10.3390/w10050574 - 28 Apr 2018

Cited by 29 | Viewed by 5871

Abstract

An operational two-dimensional real-time flood forecasting system has been developed to prevent urban inundation in Taiwan, and it uses the Delft-FEWS (Flood Early Warning System) platform to integrate the SOBEK models to forecast flooding. A new generation of smart water level gauges, integrating [...] Read more.

An operational two-dimensional real-time flood forecasting system has been developed to prevent urban inundation in Taiwan, and it uses the Delft-FEWS (Flood Early Warning System) platform to integrate the SOBEK models to forecast flooding. A new generation of smart water level gauges, integrating power charging, recording, transmission, and sensing into one, can monitor the inundation on roads in real-time. This study took Annan District in Tainan City, Taiwan, as the study object and presented the application of the flood forecasting system and smart water level gauges in the urban environment. The collected data from Storm 0611 and Typhoon Megi in 2016 were used to assess the accuracy of the flood forecasting system. The analysis of three water level stations in the drainage showed that the one-dimensional simulation results were fairly accurate. According to the 18 observed and simulated inundation depths on the roads, the true positive, false positive, false negative, and true negative values were 8, 0, 2, and 8, respectively. The accuracy, sensitivity, and precision of the flood forecasting system were 0.889, 0.800, and 1.000, respectively, indicating that the two-dimensional simulation results were highly accurate. Full article

(This article belongs to the Section Urban Water Management)

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