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Open AccessEditor’s ChoiceArticle
Flood Risk Mapping Worldwide: A Flexible Methodology and Toolbox
Water 2019, 11(11), 2371; https://doi.org/10.3390/w11112371 - 13 Nov 2019
Abstract
Flood risk assessments predict the potential consequences of flooding, leading to more effective risk management and strengthening resilience. However, adequate assessments rely on large quantities of high-quality input data. Developing regions lack reliable data or funds to acquire them. Therefore, this research has [...] Read more.
Flood risk assessments predict the potential consequences of flooding, leading to more effective risk management and strengthening resilience. However, adequate assessments rely on large quantities of high-quality input data. Developing regions lack reliable data or funds to acquire them. Therefore, this research has developed a flexible, low-cost methodology for mapping flood hazard, vulnerability and risk. A generic methodology was developed and customized for freely available data with global coverage, enabling risk assessment worldwide. The default workflow can be enriched with region-specific information when available. The practical application is assured by a modular toolbox developed on GDAL and PCRASTER. This toolbox was tested for the catchment of the river Moustiques, Haiti, for which several flood hazard maps were developed. Then, the toolbox was used to create social, economic and physical vulnerability maps. These were combined with the hazard maps to create the three corresponding flood risk maps. After creating these with the default data, more detailed information, gathered during field work, was added to verify the results of the basic workflow. These first tests of the developed toolbox show promising results. The toolbox allows policy makers in developing countries to perform reliable flood risk assessments and generate the necessary maps. Full article
(This article belongs to the Special Issue Selected Papers from 2019 World Water Week)
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Open AccessEditor’s ChoiceArticle
Irrigation-Advisor—A Decision Support System for Irrigation of Vegetable Crops
Water 2019, 11(11), 2245; https://doi.org/10.3390/w11112245 - 26 Oct 2019
Abstract
Climate change will intensify water scarcity, and therefore irrigation must be adapted to save water. Operational tools that provide watering recommendations to end-users are needed. This work presents a new tool, Irrigation-Advisor (IA), which is based on weather forecasts and is able to [...] Read more.
Climate change will intensify water scarcity, and therefore irrigation must be adapted to save water. Operational tools that provide watering recommendations to end-users are needed. This work presents a new tool, Irrigation-Advisor (IA), which is based on weather forecasts and is able to separately determine soil evaporation and crop transpiration, and thus is adaptable to a broad range of agricultural situations. By calculating several statistical indicators, IA was tested against the FAO-56 crop evapotranspiration (ETcFAO) methodology using local crop coefficients. Additionally, IA recommendations were compared with current standard practices by experienced farmers (F). Six field experiments with four widely cultivated species (endive, lettuce, muskmelon and potato) were performed in Southeast Spain. Irrigation water applied, crop yield, aboveground biomass and water productivity were determined. Crop water needs underestimations (5%–20%) were detected when comparing IA against ETcFAO, although the index of agreement proved reasonable adjustments. The IA recommendations led to water savings up to 13% when compared to F, except for lettuce, with a 31% surplus in irrigation when using IA. Crop yield was not compromised and water productivity was increased by IA. Therefore, IA mimicked the farmers′ irrigation strategies fairly well without deploying sensors on-site. Nevertheless, improvements are needed for increasing the accuracy of IA estimations. Full article
(This article belongs to the Special Issue Agriculture Water Management and Water Saving Strategies)
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Open AccessEditor’s ChoiceArticle
Sustainable Irrigation Using Non-Conventional Resources: What has Happened after 30 Years Regarding Boron Phytotoxicity?
Water 2019, 11(9), 1952; https://doi.org/10.3390/w11091952 - 19 Sep 2019
Abstract
In the Canary Islands, there is a hydrological imbalance between water consumption and renewable water availability. To provide more water resources, reverse osmosis (RO) from seawater is used. As boron (B) contents in irrigation water higher than 0.7 mg/L may be dangerous for [...] Read more.
In the Canary Islands, there is a hydrological imbalance between water consumption and renewable water availability. To provide more water resources, reverse osmosis (RO) from seawater is used. As boron (B) contents in irrigation water higher than 0.7 mg/L may be dangerous for sensible plants, B concentration in RO water (ROW) may be one of the key factors of irrigation sustainability. Some orchards have been studied after they have used drip irrigation using different water qualities for 30 years. B in water, soils, and banana leaves was determined to check the sustainability of ROW irrigation. When irrigating with ROW, in which B concentration varies between 1.0 and 1.4 mgB/L, B content in banana soils seems to be stabilized at 5–7 mg/kg, and no toxicity has been observed in banana leaves. The proper water and soil management used by the local farmers probably prevent the accumulation of higher B levels in soils. Considering water consumption of 9000 m3∙ha−1∙year−1, 8−11 kgB∙ha−1∙year−1 is applied to the soil. The banana plant removes approximately 1 kgB∙ha−1∙year−1; therefore, only 10% of the total B added gets exported. This raises the following question: is it better to use membranes that are able to reduce B in ROW, increase the leaching fraction, or blend water? Full article
(This article belongs to the Special Issue Desalination of Seawater for Agricultural Irrigation)
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Open AccessEditor’s ChoiceArticle
A Comprehensive Modelling Approach to Assess Water Use Efficiencies of Different Irrigation Management Options in Rice Irrigation Districts of Northern Italy
Water 2019, 11(9), 1833; https://doi.org/10.3390/w11091833 - 04 Sep 2019
Abstract
European rice production is concentrated in limited areas of a small number of countries. Italy is the largest European producer with over half of the total production grown on an area of 220,000 hectares, predominantly located in northern Italy. The traditional irrigation management [...] Read more.
European rice production is concentrated in limited areas of a small number of countries. Italy is the largest European producer with over half of the total production grown on an area of 220,000 hectares, predominantly located in northern Italy. The traditional irrigation management (wet seeding and continuous flooding until few weeks before harvest—WFL) requires copious volumes of water. In order to propose effective ‘water-saving’ irrigation alternatives, there is the need to collect site-specific observational data and, at the same time, to develop agro-hydrological models to upscale field/farm experimental data to a spatial scale of interest to support water management decisions and policies. The semi-distributed modelling system developed in this work, composed of three sub-models (agricultural area, groundwater zone, and channel network), allows us to describe water fluxes dynamics in rice areas at the irrigation district scale. Once calibrated for a 1000 ha district located in northern Italy using meteorological, hydrological and land-use data of a recent four-year period (2013–2016), the model was used to provide indications on the effects of different irrigation management options on district irrigation requirements, groundwater levels and irrigation/drainage network efficiency. Four scenarios considering a complete conversion of rice irrigation management over the district were implemented: WFL; DFL—dry seeding and delayed flooding; WDA—alternate wetting and drying; WFL-W—WFL followed by post-harvest winter flooding from 15 November to 15 January. Average results for the period 2013–2016 showed that DFL and WDA would lead to a reduction in summer irrigation needs compared to WFL, but also to a postponement of the peak irrigation month to June, already characterized by a strong water demand from other crops. Finally, summer irrigation consumption for WFL-W would correspond to WFL, suggesting that the considered winter flooding period ended too early to influence summer crop water needs. Full article
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Open AccessEditor’s ChoiceArticle
Crop Performance and Water Productivity of Transplanted Rice as Affected by Seedling Age and Seedling Density under Alternate Wetting and Drying Conditions in Lao PDR
Water 2019, 11(9), 1816; https://doi.org/10.3390/w11091816 - 31 Aug 2019
Abstract
Drought is common under rainfed lowlands in Lao People’s Democratic Republic, and with the uncertain onset of rains during the wet season, delay in transplanting results in yield reduction. This study aims to explore ways to ameliorate the negative influence of delayed transplanting [...] Read more.
Drought is common under rainfed lowlands in Lao People’s Democratic Republic, and with the uncertain onset of rains during the wet season, delay in transplanting results in yield reduction. This study aims to explore ways to ameliorate the negative influence of delayed transplanting on rice crop. A field experiment was conducted for two wet seasons to investigate the effect of seedling age and seedling density on crop performance in terms of grain yield and water productivity. The experiment was laid out in a split–split plot design in four replicates, with seedling age as the main plot, seedling density as the subplot, and varieties as the sub-sub plot. In both years, there were significant seedling age and variety interactions on grain yield. Higher grain yields were observed with older seedlings having stronger tillering propensity. Seedling density did not affect grain yields in both years, but on grain yield components. Shorter duration variety received less supplemental irrigation than longer duration varieties. Late transplanting improved total water productivity but decreased irrigation water productivity due to harvesting delay. The total crop growth duration (from sowing to maturity) was prolonged with transplanting delay. However, the total stay of plants in the main field (from transplanting to maturity) was reduced by 3–5 d for every 10 d delay in transplanting. The results indicated that a good selection of varieties and increasing seedling density improve crop performance and water productivity with delayed transplanting. Full article
(This article belongs to the Special Issue Water Management for Sustainable Food Production)
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Open AccessEditor’s ChoiceArticle
The Impact of Climate Change on Crop Production in Uganda—An Integrated Systems Assessment with Water and Energy Implications
Water 2019, 11(9), 1805; https://doi.org/10.3390/w11091805 - 29 Aug 2019
Abstract
With less than 3% of agricultural cropland under irrigation, subsistence farmers in Uganda are dependent on seasonal precipitation for crop production. The majority of crops grown in the country—especially staple food crops like Matooke (Plantains)—are sensitive to the availability of water throughout their [...] Read more.
With less than 3% of agricultural cropland under irrigation, subsistence farmers in Uganda are dependent on seasonal precipitation for crop production. The majority of crops grown in the country—especially staple food crops like Matooke (Plantains)—are sensitive to the availability of water throughout their growing period and hence vulnerable to climatic impacts. In response to these challenges, the Government has developed an ambitious irrigation master plan. However, the energy implications of implementing the plan have not been explored in detail. This article attempts to address three main issues involving the nexus between water, energy, crop production, and climate. The first one explores the impact of climate on rain-fed crop production. The second explores the irrigation crop water needs under selected climate scenarios. The third focuses on the energy implications of implementing the irrigation master plan. We attempt to answer the above questions using a water balance model for Uganda developed for this study. Our results, developed at a catchment level, indicate that on average there could be an 11% reduction and 8% increase in rain-fed crop production in the cumulatively driest and wettest climates, respectively. Furthermore, in the identified driest climate, the electricity required for pumping water is expected to increase by 12% on average compared to the base scenario. Full article
(This article belongs to the Special Issue Integrated Assessment of the Water–Energy–Land Nexus)
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Open AccessEditor’s ChoiceArticle
Increased Dependence on Irrigated Crop Production Across the CONUS (1945–2015)
Water 2019, 11(7), 1458; https://doi.org/10.3390/w11071458 - 14 Jul 2019
Abstract
Efficient irrigation technologies, which seem to promise reduced production costs and water consumption in heavily irrigated areas, may instead be driving increased irrigation use in areas that were not traditionally irrigated. As a result, the total dependence on supplemental irrigation for crop production [...] Read more.
Efficient irrigation technologies, which seem to promise reduced production costs and water consumption in heavily irrigated areas, may instead be driving increased irrigation use in areas that were not traditionally irrigated. As a result, the total dependence on supplemental irrigation for crop production and revenue is steadily increasing across the contiguous United States. Quantifying this dependence has been hampered by a lack of comprehensive irrigated and dryland yield and harvested area data outside of major irrigated regions, despite the importance and long history of irrigation applications in agriculture. This study used a linear regression model to disaggregate lumped agricultural statistics and estimate average irrigated and dryland yields at the state level for five major row crops: corn, cotton, hay, soybeans, and wheat. For 1945–2015, we quantified crop production, irrigation enhancement revenue, and irrigated and dryland areas in both intensively irrigated and marginally-dependent states, where both irrigated and dryland farming practices are implemented. In 2015, we found that irrigating just the five commodity crops enhanced revenue by ~$7 billion across all states with irrigation. In states with both irrigated and dryland practices, 23% of total produced area relied on irrigation, resulting in 7% more production than from dryland practices. There was a clear response to increasing biofuel demand, with the addition of more than 3.6 million ha of irrigated corn and soybeans in the last decade in marginally-dependent states. Since 1945, we estimate that yield enhancement due to irrigation has resulted in over $465 billion in increased revenue across the contiguous United States (CONUS). Example applications of this dataset include estimating historical water use, evaluating the effects of environmental policies, developing new resource management strategies, economic risk analyses, and developing tools for farmer decision making. Full article
(This article belongs to the Special Issue Precision Agriculture and Irrigation)
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Open AccessEditor’s ChoiceArticle
Adaptation Effort and Performance of Water Management Strategies to Face Climate Change Impacts in Six Representative Basins of Southern Europe
Water 2019, 11(5), 1078; https://doi.org/10.3390/w11051078 - 23 May 2019
Abstract
We evaluated different management alternatives to enhance potential water availability for agriculture under climate change scenarios. The management goal involved maximizing potential water availability, understood as the maximum volume of water supplied at a certain point of the river network that satisfies a [...] Read more.
We evaluated different management alternatives to enhance potential water availability for agriculture under climate change scenarios. The management goal involved maximizing potential water availability, understood as the maximum volume of water supplied at a certain point of the river network that satisfies a defined demand, and taking into account specified reliability requirements. We focused on potential water availability for agriculture and assumed two types of demands: urban supply and irrigation. If potential water availability was not enough to satisfy all irrigation demands, management measures were applied aiming at achieving a compromise solution between resources and demands. The methodological approach consisted of estimation and comparison of runoff for current and future period under climate change effects, calculation of water availability changes due to changes in runoff, and evaluation of the adaptation choices that can modify the distribution of water availability, under climate change. Adaptation choices include modifying water allocation to agriculture, increasing the reservoir storage capacity, improving the efficiency of urban water use, and modifying water allocation to environmental flows. These management measures were evaluated at the desired points of the river network by applying the Water Availability and Adaptation Policy Analysis (WAAPA) model. We simulated the behavior of a set of reservoirs that supply water for a set of prioritized demands, complying with specified ecological flows and accounting for evaporation losses. We applied the methodology in six representative basins of southern Europe: Duero-Douro, Ebro, Guadalquivir, Po, Maritsa-Evros, and Struma-Strymon. While in some basins, such as the Ebro or Struma-Strymon, measures can significantly increase water availability and compensate for a fraction of water scarcity due to climate change, in other basins, like the Guadalquivir, water availability cannot be enhanced by applying the management measures analyzed, and irrigation water use will have to be reduced. Full article
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Open AccessEditor’s ChoiceArticle
Analysis and Projection of Flood Hazards over China
Water 2019, 11(5), 1022; https://doi.org/10.3390/w11051022 - 16 May 2019
Abstract
Floods have been experienced with greater frequency and more severity under global climate change. To understand the flood hazard and its variation in the future, the current and future flood hazards in the 21st century in China are discussed. Floods and their trends [...] Read more.
Floods have been experienced with greater frequency and more severity under global climate change. To understand the flood hazard and its variation in the future, the current and future flood hazards in the 21st century in China are discussed. Floods and their trends are assessed using the accumulation precipitation during heavy rainfall process (AP_HRP), which are calculated based on historical meteorological observations and the outputs of a global climate model (GCM) under three Representative Concentration Pathway (RCP) scenarios. The flood-causing HRPs counted by the flood-causing critical precipitation (the 60% fractile of AP_HRP) capture more than 70% of historical flood events. The projection results indicate that the flood hazards could increase under RCP4.5 and RCP8.5 and increase slightly under RCP2.6 during the 21st century (2011–2099). The spatial characteristics of flood hazards and their increasing trends under the three RCPs are similar in most areas of China. More floods could occur in southern China, including Guangdong, Hainan, Guangxi and Fujian provinces, which could become more serious in southeastern China and the northern Yunnan province. Construction of water conservancy projects, reservoir dredging, improvement of drainage and irrigation equipment and enhancement of flood control and storage capacity can mitigate the impacts of floods and waterlogging on agriculture. Full article
(This article belongs to the Special Issue Water Resources Management Strategy Under Global Change)
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Open AccessEditor’s ChoiceArticle
The Water Governance Reform Framework: Overview and Applications to Australia, Mexico, Tanzania, U.S.A and Vietnam
Water 2019, 11(1), 137; https://doi.org/10.3390/w11010137 - 14 Jan 2019
Cited by 1
Abstract
The world faces critical water risks in relation to water availability, yet water demand is increasing in most countries. To respond to these risks, some governments and water authorities are reforming their governance frameworks to achieve convergence between water supply and demand and [...] Read more.
The world faces critical water risks in relation to water availability, yet water demand is increasing in most countries. To respond to these risks, some governments and water authorities are reforming their governance frameworks to achieve convergence between water supply and demand and ensure freshwater ecosystem services are sustained. To assist in this reform process, the Water Governance Reform Framework (WGRF) is proposed, which includes seven key strategic considerations: (1) well-defined and publicly available reform objectives; (2) transparency in decision-making and public access to available data; (3) water valuation of uses and non-uses to assess trade-offs and winners and losers; (4) compensation for the marginalized or mitigation for persons who are disadvantaged by reform; (5) reform oversight and “champions”; (6) capacity to deliver; and (7) resilient decision-making. Using these reform criteria, we assess current and possible water reforms in five countries: Murray–Darling Basin (Australia); Rufiji Basin (Tanzania); Colorado Basin (USA and Mexico); and Vietnam. We contend that the WGRF provides a valuable approach to both evaluate and to improve water governance reform and, if employed within a broader water policy cycle, will help deliver both improved water outcomes and more effective water reforms. Full article
(This article belongs to the Special Issue 10th Anniversary of Water)
Open AccessEditor’s ChoiceArticle
Water Disinfection by Immobilized Photosensitizers
Water 2019, 11(1), 26; https://doi.org/10.3390/w11010026 - 24 Dec 2018
Cited by 2
Abstract
Fresh water shortage has become a global problem. A partial solution for this problem is the use of treated and disinfected wastewater for irrigation. However, most existing wastewater disinfection methods are based on the use of aggressive chemicals or power-consuming physical processes. Photodynamic [...] Read more.
Fresh water shortage has become a global problem. A partial solution for this problem is the use of treated and disinfected wastewater for irrigation. However, most existing wastewater disinfection methods are based on the use of aggressive chemicals or power-consuming physical processes. Photodynamic eradication of waterborne bacteria by immobilized photosensitizers may be a good alternative to conventional methods. In the present work, the photosensitizers Rose Bengal sodium salt, Rose Bengal lactone, methylene blue, and hematoporphyrin were immobilized in polyethylene or polypropylene using a “green” method of co-extrusion, without addition of any chemicals, yielding polymeric strips and beads containing the photosensitizers. The antibacterial efficiency of these immobilized photosensitizers was tested against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli in batch and continuous regimes upon illumination with a white luminescent lamp. All examined photosensitizers demonstrated a good ability to decrease the bacterial concentration, up to their total eradication. Immobilized photosensitizers are proposed for batch or continuous disinfection of wastewater after secondary treatment. Full article
(This article belongs to the Special Issue Innovative Water Management and Reuse)
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Open AccessEditor’s ChoiceArticle
Analysis and Optimization of Open Circulating Cooling Water System
Water 2018, 10(11), 1592; https://doi.org/10.3390/w10111592 - 07 Nov 2018
Cited by 1
Abstract
Open circulating cooling water system is widely used in process industry. For a system with a fixed structure, the water consumption and blowdown usually change with the varying parameters such as quality and temperature. With the purpose of water saving, it is very [...] Read more.
Open circulating cooling water system is widely used in process industry. For a system with a fixed structure, the water consumption and blowdown usually change with the varying parameters such as quality and temperature. With the purpose of water saving, it is very important to optimize the operation strategy of water systems. Considering the factors including evaporation, leakage, blowdown and heat transfer, the mass and energy conservation equations of water system are established. On this basis, the quality and temperature models of makeup and blowdown water are, respectively, developed. The water consumption and discharge profiles and the optimal operating strategy of the open recirculating cooling water system under different conditions are obtained. The concept of cycles of temperature is proposed to evaluate the temperature relationship of various parts of the open circulating cooling water system. A mathematical relationship is established to analyze the influence of the water temperature on the makeup water rate of the system under the condition of insufficient cooling capacity of the cooling tower. In addition, the co-influences of quality and temperature parameters on the system are analyzed. Full article
(This article belongs to the Section Water Use and Scarcity)
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Open AccessEditor’s ChoiceArticle
New Hybrids of ANFIS with Several Optimization Algorithms for Flood Susceptibility Modeling
Water 2018, 10(9), 1210; https://doi.org/10.3390/w10091210 - 07 Sep 2018
Cited by 47
Abstract
This study presents three new hybrid artificial intelligence optimization models—namely, adaptive neuro-fuzzy inference system (ANFIS) with cultural (ANFIS-CA), bees (ANFIS-BA), and invasive weed optimization (ANFIS-IWO) algorithms—for flood susceptibility mapping (FSM) in the Haraz watershed, Iran. Ten continuous and categorical flood conditioning factors were [...] Read more.
This study presents three new hybrid artificial intelligence optimization models—namely, adaptive neuro-fuzzy inference system (ANFIS) with cultural (ANFIS-CA), bees (ANFIS-BA), and invasive weed optimization (ANFIS-IWO) algorithms—for flood susceptibility mapping (FSM) in the Haraz watershed, Iran. Ten continuous and categorical flood conditioning factors were chosen based on the 201 flood locations, including topographic wetness index (TWI), river density, stream power index (SPI), curvature, distance from river, lithology, elevation, ground slope, land use, and rainfall. The step-wise weight assessment ratio analysis (SWARA) model was adopted for the assessment of relationship between flood locations and conditioning factors. The ANFIS model, based on SWARA weights, was employed for providing FSMs with three optimization models to enhance the accuracy of prediction. To evaluate the model performance and prediction capability, root-mean-square error (RMSE) and receiver operating characteristic (ROC) curve (area under the ROC (AUROC)) were used. Results showed that ANFIS-IWO with lower RMSE (0.359) had a better performance, while ANFIS-BA with higher AUROC (94.4%) showed a better prediction capability, followed by ANFIS0-IWO (0.939) and ANFIS-CA (0.921). These models can be suggested for FSM in similar climatic and physiographic areas for developing measures to mitigate flood damages and to sustainably manage floodplains. Full article
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Open AccessEditor’s ChoiceArticle
Investigating the Dynamic Influence of Hydrological Model Parameters on Runoff Simulation Using Sequential Uncertainty Fitting-2-Based Multilevel-Factorial-Analysis Method
Water 2018, 10(9), 1177; https://doi.org/10.3390/w10091177 - 03 Sep 2018
Cited by 11
Abstract
Hydrological model parameters are generally considered to be simplified representations that characterize hydrologic processes. Therefore, their influence on runoff simulations varies with climate and catchment conditions. To investigate the influence, a three-step framework is proposed, i.e., a Latin hypercube sampling (LHS-OAT) method multivariate [...] Read more.
Hydrological model parameters are generally considered to be simplified representations that characterize hydrologic processes. Therefore, their influence on runoff simulations varies with climate and catchment conditions. To investigate the influence, a three-step framework is proposed, i.e., a Latin hypercube sampling (LHS-OAT) method multivariate regression model is used to conduct parametric sensitivity analysis; then, the multilevel-factorial-analysis method is used to quantitatively evaluate the individual and interactive effects of parameters on the hydrologic model output. Finally, analysis of the reasons for dynamic parameter changes is performed. Results suggest that the difference in parameter sensitivity for different periods is significant. The soil bulk density (SOL_BD) is significant at all times, and the parameter Soil Convention Service (SCS) runoff curve number (CN2) is the strongest during the flood period, and the other parameters are weaker in different periods. The interaction effects of CN2 and SOL_BD, as well as effective hydraulic channel conditions (CH_K2) and SOL_BD, are obvious, indicating that soil bulk density can impact the amount of loss generated by surface runoff and river recharge to groundwater. These findings help produce the best parameter inputs and improve the applicability of the model. Full article
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Open AccessEditor’s ChoiceArticle
Joint Operation of Surface Water and Groundwater Reservoirs to Address Water Conflicts in Arid Regions: An Integrated Modeling Study
Water 2018, 10(8), 1105; https://doi.org/10.3390/w10081105 - 19 Aug 2018
Cited by 8
Abstract
At the basin scale, the operation of surface water reservoirs rarely takes groundwater aquifers into consideration, which can also be regarded as reservoirs underground. This study investigates the impact of reservoir operation on the water cycle and evaluates the effect of the joint [...] Read more.
At the basin scale, the operation of surface water reservoirs rarely takes groundwater aquifers into consideration, which can also be regarded as reservoirs underground. This study investigates the impact of reservoir operation on the water cycle and evaluates the effect of the joint operation of surface water and groundwater reservoirs on the water conflict in arid regions through an integrated modeling approach. The Heihe River Basin (HRB) in northwestern China is selected as the study area. Our results show that the ecological operational strategies of a reservoir under construction in the upper HRB have a direct impact on the agricultural water uses and consequently affect other hydrological processes. The ecological operation strategy with a smaller water release and a longer duration is beneficial to securing the environmental flow towards the downstream area and to replenishing aquifers. With the joint operation of surface water and groundwater reservoirs, a balance among the agriculture water need, the groundwater sustainability in the Middle HRB and the ecological water need in the Lower HRB can be flexibly achieved. However, the joint operation can hardly improve the three aspects simultaneously. To resolve the water conflict in HRB, additional engineering and/or policy measures are desired. Full article
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Open AccessEditor’s ChoiceArticle
An Interval Quadratic Fuzzy Dependent-Chance Programming Model for Optimal Irrigation Water Allocation under Uncertainty
Water 2018, 10(6), 684; https://doi.org/10.3390/w10060684 - 25 May 2018
Cited by 3
Abstract
In this study, an interval quadratic fuzzy dependent-chance programming (IQFDCP) model is proposed for irrigation water management under uncertainty. This model can deal with the interval and fuzzy uncertainties encountered in optimal irrigation water resources allocation problems. It takes optimal credibility level of [...] Read more.
In this study, an interval quadratic fuzzy dependent-chance programming (IQFDCP) model is proposed for irrigation water management under uncertainty. This model can deal with the interval and fuzzy uncertainties encountered in optimal irrigation water resources allocation problems. It takes optimal credibility level of system revenue as the objective function for addressing the conflict between maximum system revenue and the credibility level of the system revenue. By providing three scenarios of precipitation, the optimal solutions are obtained. The developed model is applied to a case study for irrigation water allocation in Minqin Oasis, Wuwei city, northwest China. This study can help determine how much irrigation water should be allocated to different crops under the maximum credibility level of the system revenue. The optimal solutions can provide a certain credibility level of system revenue corresponding to different scenarios and mitigate the system-failure risk level of water shortages in arid areas. Moreover, because the IQFDCP can objectively reflect the interrelationship among crop irrigation water amount, system revenue, and system-failure risk level, the results are able to provide advices to decision makers for efficiently managing water resources in different scenarios. Full article
(This article belongs to the Section Water Resources Management and Governance)
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Open AccessEditor’s ChoiceArticle
Risk Analysis for Reservoir Real-Time Optimal Operation Using the Scenario Tree-Based Stochastic Optimization Method
Water 2018, 10(5), 606; https://doi.org/10.3390/w10050606 - 06 May 2018
Cited by 3
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 and Governance)
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Open AccessEditor’s ChoiceArticle
Evaluation and Hydrological Simulation of CMADS and CFSR Reanalysis Datasets in the Qinghai-Tibet Plateau
Water 2018, 10(4), 513; https://doi.org/10.3390/w10040513 - 20 Apr 2018
Cited by 19
Abstract
Multisource reanalysis datasets provide an effective way to help us understand hydrological processes in inland alpine regions with sparsely distributed weather stations. The accuracy and quality of two widely used datasets, the China Meteorological Assimilation Driving Datasets to force the SWAT model (CMADS), [...] Read more.
Multisource reanalysis datasets provide an effective way to help us understand hydrological processes in inland alpine regions with sparsely distributed weather stations. The accuracy and quality of two widely used datasets, the China Meteorological Assimilation Driving Datasets to force the SWAT model (CMADS), and the Climate Forecast System Reanalysis (CFSR) in the Qinghai-Tibet Plateau (TP), were evaluated in this paper. The accuracy of daily precipitation, max/min temperature, relative humidity and wind speed from CMADS and CFSR are firstly evaluated by comparing them with results obtained from 131 meteorological stations in the TP. Statistical results show that most elements of CMADS are superior to those of CFSR. The average correlation coefficient (R) between the maximum temperature and the minimum temperature of CMADS and CFSR ranged from 0.93 to 0.97. The root mean square error (RMSE) for CMADS and CFSR ranged from 3.16 to 3.18 °C, and ranged from 5.19 °C to 8.14 °C respectively. The average R of precipitation, relative humidity, and wind speed for CMADS are 0.46; 0.88 and 0.64 respectively, while they are 0.43, 0.52, and 0.37 for CFSR. Gridded observation data is obtained using the professional interpolation software, ANUSPLIN. Meteorological elements from three gridded data have a similar overall distribution but have a different partial distribution. The Soil and Water Assessment Tool (SWAT) is used to simulate hydrological processes in the Yellow River Source Basin of the TP. The Nash Sutcliffe coefficients (NSE) of CMADS+SWAT in calibration and validation period are 0.78 and 0.68 for the monthly scale respectively, which are better than those of CFSR+SWAT and OBS+SWAT in the Yellow River Source Basin. The relationship between snowmelt and other variables is measured by GeoDetector. Air temperature, soil moisture, and soil temperature at 1.038 m has a greater influence on snowmelt than others. Full article
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Open AccessEditor’s ChoiceArticle
New Analysis Method for Continuous Base-Flow and Availability of Water Resources Based on Parallel Linear Reservoir Models
Water 2018, 10(4), 465; https://doi.org/10.3390/w10040465 - 11 Apr 2018
Cited by 1
Abstract
Water flows in the hydrosphere through a tangled and tortuous labyrinth of ways that is the hydrological cycle. Flow separation models are an attempt to group such complexity of paths into a few components of flow and storage so as to reflect the [...] Read more.
Water flows in the hydrosphere through a tangled and tortuous labyrinth of ways that is the hydrological cycle. Flow separation models are an attempt to group such complexity of paths into a few components of flow and storage so as to reflect the overall behaviour of a basin. A new method of analysis and separation of flow components, based on equations of dynamic relations between Linear Reservoirs connected in Parallel (PLR models), is developed in this article. A synthesis of models based on mathematical filter equations is carried out in order to make comparisons with the proposed model. Reference is also made to the methodology of adjustment and calibration of the PLR models based on the recession curves of the real hydrographs. The models are tested with the continuous register of a basin located in the northeast of Spain. The simulations are carried out with two reservoir models (2R models), three reservoirs (3R models) and with a mathematical filter model to compare the results. With the results of the models, flow duration curves (FDCs) and storage duration curves (SDCs) were elaborated, thus allowing assessment of the origin of the water resources of the basin, a guarantee of their regulation and availability, the dynamic storage in the catchment, residence times and other features. Full article
(This article belongs to the Section Water Resources Management and Governance)
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Open AccessFeature PaperEditor’s ChoiceArticle
A Methodology for Measuring Microplastic Transport in Large or Medium Rivers
Water 2018, 10(4), 414; https://doi.org/10.3390/w10040414 - 02 Apr 2018
Cited by 14
Abstract
Plastic waste as a persistent contaminant of our environment is a matter of increasing concern due to the largely unknown long-term effects on biota. Although freshwater systems are known to be the transport paths of plastic debris to the ocean, most research has [...] Read more.
Plastic waste as a persistent contaminant of our environment is a matter of increasing concern due to the largely unknown long-term effects on biota. Although freshwater systems are known to be the transport paths of plastic debris to the ocean, most research has been focused on marine environments. In recent years, freshwater studies have advanced rapidly, but they rarely address the spatial distribution of plastic debris in the water column. A methodology for measuring microplastic transport at various depths that is applicable to medium and large rivers is needed. We present a new methodology offering the possibility of measuring microplastic transport at different depths of verticals that are distributed within a profile. The net-based device is robust and can be applied at high flow velocities and discharges. Nets with different sizes (41 µm, 250 µm, and 500 µm) are exposed in three different depths of the water column. The methodology was tested in the Austrian Danube River, showing a high heterogeneity of microplastic concentrations within one cross section. Due to turbulent mixing, the different densities of the polymers, aggregation, and the growth of biofilms, plastic transport cannot be limited to the surface layer of a river, and must be examined within the whole water column as for suspended sediments. These results imply that multipoint measurements are required for obtaining the spatial distribution of plastic concentration and are therefore a prerequisite for calculating the passing transport. The analysis of filtration efficiency and side-by-side measurements with different mesh sizes showed that 500 µm nets led to optimal results. Full article
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Open AccessEditor’s ChoiceArticle
In Situ Water Quality Measurements Using an Unmanned Aerial Vehicle (UAV) System
Water 2018, 10(3), 264; https://doi.org/10.3390/w10030264 - 03 Mar 2018
Cited by 15
Abstract
An unmanned aerial vehicle-assisted water quality measurement system (UAMS) was developed for in situ surface water quality measurement. A custom-built hexacopter was equipped with an open-source electronic sensors platform to measure the temperature, electrical conductivity (EC), dissolved oxygen (DO), and pH of water. [...] Read more.
An unmanned aerial vehicle-assisted water quality measurement system (UAMS) was developed for in situ surface water quality measurement. A custom-built hexacopter was equipped with an open-source electronic sensors platform to measure the temperature, electrical conductivity (EC), dissolved oxygen (DO), and pH of water. Electronic components of the system were coated with a water-resistant film, and the hexacopter was assembled with flotation equipment. The measurements were made at thirteen sampling waypoints within a 1.1 ha agricultural pond. Measurements made by an open-source multiprobe meter (OSMM) attached to the unmanned aerial vehicle (UAV) were compared to the measurements made by a commercial multiprobe meter (CMM). Percent differences between the OSMM and CMM measurements for DO, EC, pH, and temperature were 2.1 %, 3.43 %, 3.76 %, and <1.0 %, respectively. The collected water quality data was used to interpret the spatial distribution of measurements in the pond. The UAMS successfully made semiautonomous in situ water quality measurements from predetermined waypoints. Water quality maps showed homogeneous distribution of measured constituents across the pond. The concept presented in this paper can be applied to the monitoring of water quality in larger surface waterbodies. Full article
(This article belongs to the Special Issue Water Management Using Drones and Satellites in Agriculture)
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Open AccessEditor’s ChoiceArticle
Managed Aquifer Recharge (MAR) in Sustainable Urban Water Management
Water 2018, 10(3), 239; https://doi.org/10.3390/w10030239 - 26 Feb 2018
Cited by 16
Abstract
To meet increasing urban water requirements in a sustainable way, there is a need to diversify future sources of supply and storage. However, to date, there has been a lag in the uptake of managed aquifer recharge (MAR) for diversifying water sources in [...] Read more.
To meet increasing urban water requirements in a sustainable way, there is a need to diversify future sources of supply and storage. However, to date, there has been a lag in the uptake of managed aquifer recharge (MAR) for diversifying water sources in urban areas. This study draws on examples of the use of MAR as an approach to support sustainable urban water management. Recharged water may be sourced from a variety of sources and in urban centers, MAR provides a means to recycle underutilized urban storm water and treated wastewater to maximize their water resource potential and to minimize any detrimental effects associated with their disposal. The number, diversity and scale of urban MAR projects is growing internationally due to water shortages, fewer available dam sites, high evaporative losses from surface storages, and lower costs compared with alternatives where the conditions are favorable, including water treatment. Water quality improvements during aquifer storage are increasingly being documented at demonstration sites and more recently, full-scale operational urban schemes. This growing body of knowledge allows more confidence in understanding the potential role of aquifers in water treatment for regulators. In urban areas, confined aquifers provide better protection for waters recharged via wells to supplement potable water supplies. However, unconfined aquifers may generally be used for nonpotable purposes to substitute for municipal water supplies and, in some cases, provide adequate protection for recovery as potable water. The barriers to MAR adoption as part of sustainable urban water management include lack of awareness of recent developments and a lack of transparency in costs, but most importantly the often fragmented nature of urban water resources and environmental management. Full article
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Open AccessEditor’s ChoiceArticle
Analysis of Environmental Taxes to Finance Wastewater Treatment in Spain: An Opportunity for Regeneration?
Water 2018, 10(2), 226; https://doi.org/10.3390/w10020226 - 23 Feb 2018
Cited by 1
Abstract
The treatment of wastewater, financed through environmental taxes, is key to the development of a sustainable economy. The objective of this study is to verify whether the tax loads on wastewater discharges applied in Spain are effective, allowing the costs of secondary and [...] Read more.
The treatment of wastewater, financed through environmental taxes, is key to the development of a sustainable economy. The objective of this study is to verify whether the tax loads on wastewater discharges applied in Spain are effective, allowing the costs of secondary and tertiary treatments to be financed. First, the revenues collected from taxes related to the discharge of wastewater in the different Spanish regions, which reach an average value of 0.72 €/m3, are analysed. Second, the costs of secondary wastewater treatment, prolonged aeration, activated sludge with nutrient removal, and activated sludge without nutrient removal are studied. Additionally, the costs of tertiary treatments, with environmental objectives and for reuse purposes, are considered. The analysis carried out reveals high heterogeneity in the amounts collected through taxes in the different Autonomous Communities. In some cases, these amounts do not cover the costs of the treatments. An urgent review is therefore required of the financing systems applied in order to secure a level of income that can cover all the exploitation and investment costs incurred. Full article
Open AccessEditor’s ChoiceArticle
Calibration of Spatially Distributed Hydrological Processes and Model Parameters in SWAT Using Remote Sensing Data and an Auto-Calibration Procedure: A Case Study in a Vietnamese River Basin
Water 2018, 10(2), 212; https://doi.org/10.3390/w10020212 - 16 Feb 2018
Cited by 13
Abstract
In this paper, evapotranspiration (ET) and leaf area index (LAI) were used to calibrate the SWAT model, whereas remotely sensed precipitation and other climatic parameters were used as forcing data for the 6300 km2 Day Basin, a tributary of the Red River [...] Read more.
In this paper, evapotranspiration (ET) and leaf area index (LAI) were used to calibrate the SWAT model, whereas remotely sensed precipitation and other climatic parameters were used as forcing data for the 6300 km2 Day Basin, a tributary of the Red River in Vietnam. The efficacy of the Sequential Uncertainty Fitting (SUFI-2) parameter sensitivity and optimization model was tested with area specific remote sensing input parameters for every Hydrological Response Units (HRU), rather than with measurements of river flow representing a large set of HRUs, i.e., a bulk calibration. Simulated monthly ET correlations with remote sensing estimates showed an R2 = 0.71, Nash–Sutcliffe Efficiency NSE = 0.65, and Kling Gupta Efficiency KGE = 0.80 while monthly LAI showed correlations of R2 = 0.59, NSE = 0.57 and KGE = 0.83 over a five-year validation period. Accumulated modelled ET over the 5-year calibration period amounted to 5713 mm compared to 6015 mm of remotely sensed ET, yielding a difference of 302 mm (5.3%). The monthly flow at two flow measurement stations were adequately estimated (R2 = 0.78 and 0.55, NSE = 0.71 and 0.63, KGE = 0.59 and 0.75 for Phu Ly and Ninh Binh, respectively). This outcome demonstrates the capability of SWAT model to obtain spatial and accurate simulation of eco-hydrological processes, also when rivers are ungauged and the water withdrawal system is complex. Full article
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Open AccessFeature PaperEditor’s ChoiceArticle
Improving the Multi-Objective Performance of Rainwater Harvesting Systems Using Real-Time Control Technology
Water 2018, 10(2), 147; https://doi.org/10.3390/w10020147 - 02 Feb 2018
Cited by 10
Abstract
Many studies have identified the potential of rainwater harvesting (RWH) systems to simultaneously augment potable water supply and reduce delivery of uncontrolled stormwater flows to downstream drainage networks. Potentially, such systems could also play a role in the controlled delivery of water to [...] Read more.
Many studies have identified the potential of rainwater harvesting (RWH) systems to simultaneously augment potable water supply and reduce delivery of uncontrolled stormwater flows to downstream drainage networks. Potentially, such systems could also play a role in the controlled delivery of water to urban streams in ways which mimic baseflows. The performance of RWH systems to achieve these three objectives could be enhanced using Real-Time Control (RTC) technology to receive rainfall forecasts and initiate pre-storm release in real time, although few studies have explored such potential. We used continuous simulation to model the ability of a range of allotment-scale RWH systems to simultaneously deliver: (i) water supply; (ii) stormwater retention; and (iii) baseflow restoration. We compared the performance of RWH systems with RTC technology to conventional RWH systems and also systems designed with a passive baseflow release, rather than the active (RTC) configuration. We found that RWH systems employing RTC technology were generally superior in simultaneously achieving water supply, stormwater retention and baseflow restoration benefits compared with the other types of system tested. The active operation provided by RTC allows the system to perform optimally across a wider range of climatic conditions, but needs to be carefully designed. We conclude that the active release mechanism employing RTC technology exhibits great promise; its ability to provide centralised control and failure detection also opens the possibility of delivering a more reliable rainwater harvesting system, which can be readily adapted to varying climate over both the short and long term. Full article
(This article belongs to the Special Issue Development of Alternative Water Sources in the Urban Sector)
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Open AccessEditor’s ChoiceArticle
Multi-Stakeholder Development of a Serious Game to Explore the Water-Energy-Food-Land-Climate Nexus: The SIM4NEXUS Approach
Water 2018, 10(2), 139; https://doi.org/10.3390/w10020139 - 01 Feb 2018
Cited by 15
Abstract
Water, energy, food, land and climate form a tightly-connected nexus in which actions on one sector impact other sectors, creating feedbacks and unanticipated consequences. This is especially because at present, much scientific research and many policies are constrained to single discipline/sector silos that [...] Read more.
Water, energy, food, land and climate form a tightly-connected nexus in which actions on one sector impact other sectors, creating feedbacks and unanticipated consequences. This is especially because at present, much scientific research and many policies are constrained to single discipline/sector silos that are often not interacting (e.g., water-related research/policy). However, experimenting with the interaction and determining how a change in one sector could impact another may require unreasonable time frames, be very difficult in practice and may be potentially dangerous, triggering any one of a number of unanticipated side-effects. Current modelling often neglects knowledge from practice. Therefore, a safe environment is required to test the potential cross-sectoral implications of policy decisions in one sector on other sectors. Serious games offer such an environment by creating realistic ‘simulations’, where long-term impacts of policies may be tested and rated. This paper describes how the ongoing (2016–2020) Horizon2020 project SIM4NEXUS will develop serious games investigating potential plausible cross-nexus implications and synergies due to policy interventions for 12 multi-scale case studies ranging from regional to global. What sets these games apart is that stakeholders and partners are involved in all aspects of the modelling definition and process, from case study conceptualisation, quantitative model development including the implementation and validation of each serious game. Learning from playing a serious game is justified by adopting a proof-of-concept for a specific regional case study in Sardinia (Italy). The value of multi-stakeholder involvement is demonstrated, and critical lessons learned for serious game development in general are presented. Full article
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Open AccessEditor’s ChoiceArticle
Hydrologic Regime Changes in a High-Latitude Glacierized Watershed under Future Climate Conditions
Water 2018, 10(2), 128; https://doi.org/10.3390/w10020128 - 30 Jan 2018
Cited by 3
Abstract
A calibrated conceptual glacio-hydrological monthly water balance model (MWBMglacier) was used to evaluate future changes in water partitioning in a high-latitude glacierized watershed in Southcentral Alaska under future climate conditions. The MWBMglacier was previously calibrated and evaluated against streamflow measurements, literature values of [...] Read more.
A calibrated conceptual glacio-hydrological monthly water balance model (MWBMglacier) was used to evaluate future changes in water partitioning in a high-latitude glacierized watershed in Southcentral Alaska under future climate conditions. The MWBMglacier was previously calibrated and evaluated against streamflow measurements, literature values of glacier mass balance change, and satellite-based observations of snow covered area, evapotranspiration, and total water storage. Output from five global climate models representing two future climate scenarios (RCP 4.5 and RCP 8.5) was used with the previously calibrated parameters to drive the MWBMglacier at 2 km spatial resolution. Relative to the historical period 1949–2009, precipitation will increase and air temperature in the mountains will be above freezing for an additional two months per year by mid-century which significantly impacts snow/rain partitioning and the generation of meltwater from snow and glaciers. Analysis of the period 1949–2099 reveals that numerous hydrologic regime shifts already occurred or are projected to occur in the study area including glacier accumulation area, snow covered area, and forest vulnerability. By the end of the century, Copper River discharge is projected to increase by 48%, driven by 21% more precipitation and 53% more glacial melt water (RCP 8.5) relative to the historical period (1949–2009). Full article
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Open AccessEditor’s ChoiceArticle
Shifting the Framework of Canadian Water Governance through Indigenous Research Methods: Acknowledging the Past with an Eye on the Future
Water 2018, 10(1), 49; https://doi.org/10.3390/w10010049 - 10 Jan 2018
Cited by 13
Abstract
First Nations communities in Canada are disproportionately affected by poor water quality. As one example, many communities have been living under boil water advisories for decades, but government interventions to date have had limited impact. This paper examines the importance of using Indigenous [...] Read more.
First Nations communities in Canada are disproportionately affected by poor water quality. As one example, many communities have been living under boil water advisories for decades, but government interventions to date have had limited impact. This paper examines the importance of using Indigenous research methodologies to address current water issues affecting First Nations. The work is part of larger project applying decolonizing methodologies to Indigenous water governance. Because Indigenous epistemologies are a central component of Indigenous research methods, our analysis begins with presenting a theoretical framework for understanding Indigenous water relations. We then consider three cases of innovative Indigenous research initiatives that demonstrate how water research and policy initiatives can adopt a more Indigenous-centered approach in practice. Cases include (1) an Indigenous Community-Based Health Research Lab that follows a two-eyed seeing philosophy (Saskatchewan); (2) water policy research that uses collective knowledge sharing frameworks to facilitate respectful, non-extractive conversations among Elders and traditional knowledge holders (Ontario); and (3) a long-term community-based research initiative on decolonizing water that is practicing reciprocal learning methodologies (British Columbia, Alberta). By establishing new water governance frameworks informed by Indigenous research methods, the authors hope to promote innovative, adaptable solutions, rooted in Indigenous epistemologies. Full article
Open AccessEditor’s ChoiceArticle
Role of Seawater Desalination in the Management of an Integrated Water and 100% Renewable Energy Based Power Sector in Saudi Arabia
Water 2018, 10(1), 3; https://doi.org/10.3390/w10010003 - 22 Dec 2017
Cited by 19
Abstract
This work presents a pathway for Saudi Arabia to transition from the 2015 power structure to a 100% renewable energy-based system by 2050 and investigates the benefits of integrating the power sector with the growing desalination sector. Saudi Arabia can achieve 100% renewable [...] Read more.
This work presents a pathway for Saudi Arabia to transition from the 2015 power structure to a 100% renewable energy-based system by 2050 and investigates the benefits of integrating the power sector with the growing desalination sector. Saudi Arabia can achieve 100% renewable energy power system by 2040 while meeting increasing water demand through seawater reverse osmosis (SWRO) and multiple effect distillation (MED) desalination plants. The dominating renewable energy sources are PV single-axis tracking and wind power plants with 243 GW and 83 GW, respectively. The levelised cost of electricity (LCOE) of the 2040 system is 49 €/MWh and decreases to 41 €/MWh by 2050. Corresponding levelised cost of water (LCOW) is found to be 0.8 €/m3 and 0.6 €/m3. PV single-axis tracking dominates the power sector. By 2050 solar PV accounts for 79% of total electricity generation. Battery storage accounts for 41% of total electricity demand. In the integrated scenario, due to flexibility provided by SWRO plants, there is a reduced demand for battery storage and power-to-gas (PtG) plants as well as a reduction in curtailment. Thus, the annual levelised costs of the integrated scenario is found to be 1–3% less than the non-integrated scenario. Full article
(This article belongs to the Special Issue Sustainable Water Supply through Desalination and Wastewater Reuse)
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Open AccessEditor’s ChoiceArticle
Research on the Phenomenon of Chinese Residents’ Spiritual Contagion for the Reuse of Recycled Water Based on SC-IAT
Water 2017, 9(11), 846; https://doi.org/10.3390/w9110846 - 02 Nov 2017
Cited by 99
Abstract
Recycled water has been widely recognized in the world as an effective approach to relieve the issue of water shortage. Meanwhile, with several decades of development, the insufficiency of technology is no longer the primary factor that restricts the popularization of recycled water. [...] Read more.
Recycled water has been widely recognized in the world as an effective approach to relieve the issue of water shortage. Meanwhile, with several decades of development, the insufficiency of technology is no longer the primary factor that restricts the popularization of recycled water. What makes it difficult to promote the concept of reusing recycled water in China? To solve this issue, a special experiment on the public’s attitude towards the reuse of recycled water was designed based on a Single Category Implicit Association Test (SC-IAT), so as to avoid factors like social preference that can influence the survey results, and to gain the public’s negative implicit attitude towards reusing recycled water reuse, which is close to the public’s real attitude to it. From the perspective of implicit attitude, this research testifies the “spiritual contagion” phenomenon of the public, which refers to refusing recycled water reuse because recycled water is made from sewage treatment. By comparing the implicit attitude to recycled water reuse with the explicit attitude that is acquired from self-reporting questionnaires about reusing recycled water, this research finds that the implicit attitude is more positive than the explicit attitude, which accounts for the phenomenon of “best game no one played” in the promotion of the recycled water reuse, that is, the public though applauding the environment-friendly policy, will not actually use the recycled water. Full article
Open AccessEditor’s ChoiceArticle
Informing National Food and Water Security Policy through Water Footprint Assessment: the Case of Iran
Water 2017, 9(11), 831; https://doi.org/10.3390/w9110831 - 29 Oct 2017
Cited by 20
Abstract
Iran’s focus on food self-sufficiency has led to an emphasis on increasing water volumes available for irrigation with little attention to water use efficiency, and no attention at all to the role of consumption and trade. To better understand the development of water [...] Read more.
Iran’s focus on food self-sufficiency has led to an emphasis on increasing water volumes available for irrigation with little attention to water use efficiency, and no attention at all to the role of consumption and trade. To better understand the development of water consumption in relation to food production, consumption, and trade, we carried out the first comprehensive water footprint assessment (WFA) for Iran, for the period 1980–2010, and estimated the water saving per province associated with interprovincial and international crop trade. Based on the AquaCrop model, we estimated the green and blue water footprint (WF) related to both the production and consumption of 26 crops, per year and on a daily basis, for 30 provinces of Iran. We find that, in the period 1980–2010, crop production increased by 175%, the total WF of crop production by 122%, and the blue WF by 20%. The national population grew by 92%, and the crop consumption per capita by 20%, resulting in a 130% increase in total food consumption and a 110% increase in the total WF of national crop consumption. In 2010, 26% of the total water consumption in the semi-arid region served the production of crops for export to other regions within Iran (mainly cereals) or abroad (mainly fruits and nuts). Iran’s interprovincial virtual water trade grew by a factor of 1.6, which was mainly due to increased interprovincial trade in cereals, nuts, and fruits. Current Iranian food and water policy could be enriched by reducing the WFs of crop production to certain benchmark levels per crop and climatic region and aligning cropping patterns to spatial differences in water availability and productivities, and by paying due attention to the increasing food consumption per capita in Iran. Full article
(This article belongs to the Special Issue Progress in Water Footprint Assessment) Printed Edition available
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Open AccessEditor’s ChoiceArticle
How to Improve Water Usage Efficiency? Characterization of Family Farms in A Semi-Arid Area
Water 2017, 9(10), 785; https://doi.org/10.3390/w9100785 - 13 Oct 2017
Cited by 1
Abstract
Water scarcity in Spain is partly due to poor management of this resource in the agricultural sector. The main aim of this study is to present the major factors related to water usage efficiency in farming. It focuses on the Almería coast, southeast [...] Read more.
Water scarcity in Spain is partly due to poor management of this resource in the agricultural sector. The main aim of this study is to present the major factors related to water usage efficiency in farming. It focuses on the Almería coast, southeast Spain, which is one of the most arid areas of the country, and in particular, on family farms as the main direct managers of water use in this zone. Many of these farms are among the most water efficient in Spanish agriculture but this efficiency is not generalized throughout the sector. This work conducts a comprehensive assessment of water performance in this area, using on-farm water-use, structural, socio-economic, and environmental information. Two statistical techniques are used: descriptive analysis and cluster analysis. Thus, two groups are identified: farms that are less and farms that are more efficient regarding water usage. By analyzing both the common characteristics within each group and the differences between the groups with a one-way ANOVA analysis, several conclusions can be reached. The main differences between the two clusters center on the extent to which innovation and new technologies are used in irrigation. The most water efficient farms are characterized by more educated farmers, a greater degree of innovation, new irrigation technology, and an awareness of water issues and environmental sustainability. The findings of this study can be extended to farms in similar arid and semi-arid areas and contribute to fostering appropriate policies to improve the efficiency of water usage in the agricultural sector. Full article
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Open AccessEditor’s ChoiceArticle
Streamflow and Sediment Yield Prediction for Watershed Prioritization in the Upper Blue Nile River Basin, Ethiopia
Water 2017, 9(10), 782; https://doi.org/10.3390/w9100782 - 12 Oct 2017
Cited by 23
Abstract
Inappropriate use of land and poor ecosystem management have accelerated land degradation and reduced the storage capacity of reservoirs. To mitigate the effect of the increased sediment yield, it is important to identify erosion-prone areas in a 287 km2 catchment in Ethiopia. The [...] Read more.
Inappropriate use of land and poor ecosystem management have accelerated land degradation and reduced the storage capacity of reservoirs. To mitigate the effect of the increased sediment yield, it is important to identify erosion-prone areas in a 287 km2 catchment in Ethiopia. The objectives of this study were to: (1) assess the spatial variability of sediment yield; (2) quantify the amount of sediment delivered into the reservoir; and (3) prioritize sub-catchments for watershed management using the Soil and Water Assessment Tool (SWAT). The SWAT model was calibrated and validated using SUFI-2, GLUE, ParaSol, and PSO SWAT-CUP optimization algorithms. For most of the SWAT-CUP simulations, the observed and simulated river discharge were not significantly different at the 95% level of confidence (95PPU), and sources of uncertainties were captured by bracketing more than 70% of the observed data. This catchment prioritization study indicated that more than 85% of the sediment was sourced from lowland areas (slope range: 0–8%) and the variation in sediment yield was more sensitive to the land use and soil type prevailing in the area regardless of the terrain slope. Contrary to the perception of the upland as an important source of sediment, the lowland in fact was the most important source of sediment and should be the focus area for improved land management practice to reduce sediment delivery into storage reservoirs. The research also showed that lowland erosion-prone areas are typified by extensive agriculture, which causes significant modification of the landscape. Tillage practice changes the infiltration and runoff characteristics of the land surface and interaction of shallow groundwater table and saturation excess runoff, which in turn affects the delivery of water and sediment to the reservoir and catchment evapotranspiration. Full article
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Open AccessEditor’s ChoiceArticle
Optimal Hedging Rules for Water Supply Reservoir Operations under Forecast Uncertainty and Conditional Value-at-Risk Criterion
Water 2017, 9(8), 568; https://doi.org/10.3390/w9080568 - 30 Jul 2017
Cited by 15
Abstract
Hedging rules for water supply reservoir operations provide guidelines for balancing the consequences of competing water allocations. When inflow forecast uncertainty is addressed, hedging acts as insurances for offsetting the negative influence of water shortage in the future, especially when drought is anticipated. [...] Read more.
Hedging rules for water supply reservoir operations provide guidelines for balancing the consequences of competing water allocations. When inflow forecast uncertainty is addressed, hedging acts as insurances for offsetting the negative influence of water shortage in the future, especially when drought is anticipated. This study used a risk-averse criterion, the conditional value-at-risk (CVaR), rather than the expected value (EV) criterion, to rationalize water delivery for overcoming the shortcomings of risk-neutral hedging rules in minimizing water shortage impacts in unfavorable realizations, in which actual inflow is less than anticipated. A two-period hedging model with the objective of maximizing the CVaR of total benefits from water delivery and water storage is established, and the optimal hedging rules using first-order optimality condition are analytically derived. Differences in hedging rules under the two criteria are highlighted by theoretical analysis and numerical experiments. The methods are applied to guide the operations of a water supply reservoir, and results show that: (1) the hedging rules under the EV criterion are special cases under the CVaR criterion; (2) water delivery in the current period would be greatly curtailed under the high influence of forecast uncertainty or the significant risk-averse attitude of decision makers; (3) hedging to maximize the CVaR of total benefit is at the cost of reducing the EV of total benefit; and (4) in real-time operations, compared with the hedging policies under the EV criterion, the hedging policies under the CVaR criterion would be more effective when applied to dry and extremely dry hydrological conditions, especially when inflow is overestimated. These implications provide new insights into rationing water supply and risk aversion. Full article
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Open AccessEditor’s ChoiceArticle
Agricultural Water Productivity Oriented Water Resources Allocation Based on the Coordination of Multiple Factors
Water 2017, 9(7), 490; https://doi.org/10.3390/w9070490 - 05 Jul 2017
Cited by 13
Abstract
Agricultural water productivity (AWP), which is associated with multiple factors, is an important index for measuring the effectiveness of agricultural water management. The purpose of this study is to promote AWP through optimally allocating limited agricultural water resources with the coordination of related [...] Read more.
Agricultural water productivity (AWP), which is associated with multiple factors, is an important index for measuring the effectiveness of agricultural water management. The purpose of this study is to promote AWP through optimally allocating limited agricultural water resources with the coordination of related elements. Firstly, the coordination effects of multiple factors related to AWP are quantified as relative optimum membership degrees based on the fuzzy optimum selecting theory. Secondly, based on the relative optimum membership degrees for various crops, a linear fractional programming model is established to maximize AWP in agricultural water resources allocation. Thirdly, the impacts of the allocation schemes on the development of social-economy and ecological environment are discussed using the multi-dimensional regulation theory. The developed integrated system has advantages in increasing agricultural water productivity through the coordination of multiple factors with aspects of economy, society and resources. Moreover, the system is capable of screening schemes considering harmonious development of resources, economy, society and ecology based on optimization results, providing decision makers with more sustainable schemes for irrigation water allocation. The integrated system including the aforementioned three parts is applied to a real-world case study in China to demonstrate its feasibility and applicability. Different water allocation schemes for various crops under different scenarios were obtained. The average value of AWP is 1.85 kg/m3, which is 0.31 kg/m3 higher than the current value of AWP. An optimum scheme with 1.1405 × 108 m3 of water being allocated was also selected due to its highest level of coordination for resources, economy, society and ecology. The developed system can provide an effective method for AWP promotion. The obtained results can help local decision makers adjust water resources allocation schemes. Full article
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Open AccessEditor’s ChoiceArticle
Optimal Use of Agricultural Water and Land Resources through Reconfiguring Crop Planting Structure under Socioeconomic and Ecological Objectives
Water 2017, 9(7), 488; https://doi.org/10.3390/w9070488 - 04 Jul 2017
Cited by 19
Abstract
Many economic, social and ecological problems can be attributed to the scarcity and mismanagement of water and land resources. In this study, a multi-objective fuzzy–robust programming (MOFRP) method was developed for supporting the optimal use of land and water resources in agriculture. MOFRP [...] Read more.
Many economic, social and ecological problems can be attributed to the scarcity and mismanagement of water and land resources. In this study, a multi-objective fuzzy–robust programming (MOFRP) method was developed for supporting the optimal use of land and water resources in agriculture. MOFRP improved existing methods through taking ecological services of crop cultivation into account. It was also capable of reflecting fuzziness in preferences, priorities and parameters that were largely neglected in previous agricultural decision making. This method was applied to address a case in arid northwestern China. Optimal plans of crop cultivation reconfiguration were generated for sustaining local development under economic, ecological and social objectives as well as physical restraints in water and land resources. Compared to the status quo, the optimized plan would increase economic and ecological benefits by 12.2% and 18.8%, respectively. The efficiency of irrigation water could also be enhanced with the economic and ecological benefits per unit water being raised and the water consumption per unit land being reduced. The comparisons of the MOFRP model to four alternatives validated that it was capable of achieving satisfactory benefits and reducing system-violation risks without neglecting valuable uncertain information and ecological services of crops. The proposed method was also applicable to other multi-objective management problems under uncertainty without loss of generality. Full article
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Open AccessEditor’s ChoiceArticle
Stability Analysis of Hydrodynamic Pressure Landslides with Different Permeability Coefficients Affected by Reservoir Water Level Fluctuations and Rainstorms
Water 2017, 9(7), 450; https://doi.org/10.3390/w9070450 - 22 Jun 2017
Cited by 21
Abstract
It is significant to study the variations in the stability coefficients of hydrodynamic pressure landslides with different permeability coefficients affected by reservoir water level fluctuations and rainstorms. The Sifangbei landslide in Three Gorges Reservoir area is used as case study. Its stability coefficients [...] Read more.
It is significant to study the variations in the stability coefficients of hydrodynamic pressure landslides with different permeability coefficients affected by reservoir water level fluctuations and rainstorms. The Sifangbei landslide in Three Gorges Reservoir area is used as case study. Its stability coefficients are simulated based on saturated-unsaturated seepage theory and finite element analysis. The operating conditions of stability coefficients calculation are reservoir water level variations between 175 m and 145 m, different rates of reservoir water level fluctuations, and a three-day continuous rainstorm. Results show that the stability coefficient of the hydrodynamic pressure landslide decreases with the drawdown of the reservoir water level, and a rapid drawdown rate leads to a small stability coefficient when the permeability coefficient ranges from 1.16 × 10−6 m/s to 4.64 × 10−5 m/s. Additionally, the landslide stability coefficient increases as the reservoir water level increases, and a rapid increase in the water level leads to a high stability coefficient when the permeability coefficient ranges from 1.16 × 10−6 m/s to 4.64 × 10−5 m/s. The landslide stability coefficient initially decreases and then increases as the reservoir water level declines when the permeability coefficient is greater than 4.64 × 10−5 m/s. Moreover, for structures with the same landslide, the landslide stability coefficient is most sensitive to the change in the rate of reservoir water level drawdown when the permeability coefficient increases from 1.16 × 10−6 m/s to 1.16 × 10−4 m/s. Additionally, the rate of decrease in the stability coefficient increases as the permeability coefficient increases. Finally, the three-day rainstorm leads to a significant reduction in landslide stability, and the rate of decrease in the stability coefficient initially increases and then decreases as the permeability coefficient increases. Full article
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Open AccessEditor’s ChoiceArticle
Development of Resilience Index Based on Flooding Damage in Urban Areas
Water 2017, 9(6), 428; https://doi.org/10.3390/w9060428 - 13 Jun 2017
Cited by 13
Abstract
Flooding volume in urban areas is not linearly proportional to flooding damage because, in some areas, no flooding damage occurs until the flooding depth reaches a certain point, whereas flooding damage occurs in other areas whenever flooding occurs. Flooding damage is different from [...] Read more.
Flooding volume in urban areas is not linearly proportional to flooding damage because, in some areas, no flooding damage occurs until the flooding depth reaches a certain point, whereas flooding damage occurs in other areas whenever flooding occurs. Flooding damage is different from flooding volume because each subarea has different components. A resilience index for urban drainage systems was developed based on flooding damage. In this study, the resilience index based on flooding damage in urban areas was applied to the Sintaein basin in Jeongup, Korea. The target watershed was divided into five subareas according to the status of land use in each subarea. The damage functions between flooding volume and flooding damage were calculated by multi-dimensional flood damage analysis. The extent of flooding damage per minute was determined from the results of flooding volume per minute using damage functions. The values of the resilience index based on flooding damages were distributed from 0.797292 to 0.933741. The resilience index based on flooding damage suggested in this study can reflect changes in urban areas and can be used for the evaluation of flood control plans such as the installation, replacement, and rehabilitation of drainage facilities. Full article
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Open AccessEditor’s ChoiceArticle
Application of GIS-Interval Rough AHP Methodology for Flood Hazard Mapping in Urban Areas
Water 2017, 9(6), 360; https://doi.org/10.3390/w9060360 - 24 May 2017
Cited by 36
Abstract
Floods are natural disasters with significant socio-economic consequences. Urban areas with uncontrolled urban development, rapid population growth, an unregulated municipal system and an unplanned change of land use belong to the highly sensitive areas where floods cause devastating economic and social losses. The [...] Read more.
Floods are natural disasters with significant socio-economic consequences. Urban areas with uncontrolled urban development, rapid population growth, an unregulated municipal system and an unplanned change of land use belong to the highly sensitive areas where floods cause devastating economic and social losses. The aim of this paper is to present a reliable GIS multi-criteria methodology for hazard zones’ mapping of flood-prone areas in urban areas. The proposed methodology is based on the combined application of geographical information systems (GIS) and multi-criteria decision analysis (MCDA). The methodology considers six factors that are relevant to the hazard of flooding in urban areas: the height, slope, distance to the sewage network, the distance from the water surface, the water table and land use. The expert evaluation takes into account the nature and severity of observed criteria, and it is tested using three scenarios: the modalities of the analytic hierarchy process (AHP). The first of them uses a new approach to the exploitation of uncertainty in the application of the AHP technique, the interval rough numbers (IR’AHP). The second one uses the fuzzy technique for the exploitation of uncertainty with the AHP method (F’AHP), and the third scenario contemplates the use of the traditional (crisp) AHP method. The proposed methodology is demonstrated in Palilula Municipality, Belgrade, Serbia. In the last few decades, Palilula Municipality has been repeatedly devastated by extreme flood events. These floods severely affected the transportation networks and other infrastructure. Historical flood inundation data have been used in the validation process. The final urban flood hazard map proves a satisfactory agreement between the flood hazard zones and the spatial distribution of historical floods that happened in the last 58 years. The results indicate that the scenario in which the IR’AHP methodology is used provides the highest level of compatibility with historical data on floods. The produced map showed that the areas of very high flood hazard are located on the left Danube River bank. These areas are characterized by lowland morphology, gentle slope, sewage network, expansion of impermeable locations and intense urbanization. The proposed GIS-IR’AHP methodology and the results of this study provide a good basis for developing a system of flood hazard management in urban areas and can be successfully used for spatial city development policy. Full article
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Open AccessEditor’s ChoiceArticle
Characterizing Precipitation Variability and Trends in the World’s Mediterranean-Climate Areas
Water 2017, 9(4), 259; https://doi.org/10.3390/w9040259 - 06 Apr 2017
Cited by 17
Abstract
The Mediterranean climate is principally characterized by warm, dry summers and cool, wet winters. However, there are large variations in precipitation dynamics in regions with this climate type. We examined the variability of precipitation within and among Mediterranean-climate areas, and classified the Mediterranean [...] Read more.
The Mediterranean climate is principally characterized by warm, dry summers and cool, wet winters. However, there are large variations in precipitation dynamics in regions with this climate type. We examined the variability of precipitation within and among Mediterranean-climate areas, and classified the Mediterranean climate as wet, moderate, or dry based on annual precipitation; and strongly, moderately, or weakly seasonal based on percentage of precipitation during summer. Mediterranean biomes are mostly dry (<700 mm annually) but some areas are wet (>1300 mm annually); and many areas are weakly seasonal (>12% of annual precipitation during summer). We also used NOAA NCDC climate records to characterize interannual variability of annual and dry-season precipitation, as well as trends in annual, winter, and dry-season precipitation for 337 sites that met the data quality criteria from 1975 to 2015. Most significantly, sites in many Mediterranean-climate regions show downward trends in annual precipitation (southern California, Spain, Australia, Chile, and Northern Italy); and most of North America, the Mediterranean basin, and Chile showed downward trends in summer precipitation. Variations in annual and summer precipitation likely contribute to the high biodiversity and endemism characteristic of Mediterranean-climate biomes; the data indicate trends toward harsher conditions over the past 40 years. Full article
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Open AccessEditor’s ChoiceArticle
Open Surface Water Mapping Algorithms: A Comparison of Water-Related Spectral Indices and Sensors
Water 2017, 9(4), 256; https://doi.org/10.3390/w9040256 - 05 Apr 2017
Cited by 34
Abstract
Open surface water bodies play an important role in agricultural and industrial production, and are susceptible to climate change and human activities. Remote sensing data has been increasingly used to map open surface water bodies at local, regional, and global scales. In addition [...] Read more.
Open surface water bodies play an important role in agricultural and industrial production, and are susceptible to climate change and human activities. Remote sensing data has been increasingly used to map open surface water bodies at local, regional, and global scales. In addition to image statistics-based supervised and unsupervised classifiers, spectral index- and threshold-based approaches have also been widely used. Many water indices have been proposed to identify surface water bodies; however, the differences in performances of these water indices as well as different sensors on water body mapping are not well documented. In this study, we reviewed and compared existing open surface water body mapping approaches based on six widely-used water indices, including the tasseled cap wetness index (TCW), normalized difference water index (NDWI), modified normalized difference water index (mNDWI), sum of near infrared and two shortwave infrared bands (Sum457), automated water extraction index (AWEI), land surface water index (LSWI), as well as three medium resolution sensors (Landsat 7 ETM+, Landsat 8 OLI, and Sentinel-2 MSI). A case region in the Poyang Lake Basin, China, was selected to examine the accuracies of the open surface water body maps from the 27 combinations of different algorithms and sensors. The results showed that generally all the algorithms had reasonably high accuracies with Kappa Coefficients ranging from 0.77 to 0.92. The NDWI-based algorithms performed slightly better than the algorithms based on other water indices in the study area, which could be related to the pure water body dominance in the region, while the sensitivities of water indices could differ for various water body conditions. The resultant maps from Landsat 8 and Sentinel-2 data had higher overall accuracies than those from Landsat 7. Specifically, all three sensors had similar producer accuracies while Landsat 7 based results had a lower user accuracy. This study demonstrates the improved performance in Landsat 8 and Sentinel-2 for open surface water body mapping efforts. Full article
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Open AccessEditor’s ChoiceArticle
Clustering and Support Vector Regression for Water Demand Forecasting and Anomaly Detection
Water 2017, 9(3), 224; https://doi.org/10.3390/w9030224 - 18 Mar 2017
Cited by 31
Abstract
This paper presents a completely data-driven and machine-learning-based approach, in two stages, to first characterize and then forecast hourly water demand in the short term with applications of two different data sources: urban water demand (SCADA data) and individual customer water consumption (AMR [...] Read more.
This paper presents a completely data-driven and machine-learning-based approach, in two stages, to first characterize and then forecast hourly water demand in the short term with applications of two different data sources: urban water demand (SCADA data) and individual customer water consumption (AMR data). In the first case, reliable forecasting can be used to optimize operations, particularly the pumping schedule, in order to reduce energy-related costs, while in the second case, the comparison between forecast and actual values may support the online detection of anomalies, such as smart meter faults, fraud or possible cyber-physical attacks. Results are presented for a real case: the water distribution network in Milan. Full article
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Open AccessEditor’s ChoiceArticle
Advancing Sequential Managed Aquifer Recharge Technology (SMART) Using Different Intermediate Oxidation Processes
Water 2017, 9(3), 221; https://doi.org/10.3390/w9030221 - 17 Mar 2017
Cited by 23
Abstract
Managed aquifer recharge (MAR) systems are an efficient barrier for many contaminants. The biotransformation of trace organic chemicals (TOrCs) strongly depends on the redox conditions as well as on the dissolved organic carbon availability. Oxic and oligotrophic conditions are favored for enhanced TOrCs [...] Read more.
Managed aquifer recharge (MAR) systems are an efficient barrier for many contaminants. The biotransformation of trace organic chemicals (TOrCs) strongly depends on the redox conditions as well as on the dissolved organic carbon availability. Oxic and oligotrophic conditions are favored for enhanced TOrCs removal which is obtained by combining two filtration systems with an intermediate aeration step. In this study, four parallel laboratory-scale soil column experiments using different intermittent aeration techniques were selected to further optimize TOrCs transformation during MAR: no aeration, aeration with air, pure oxygen and ozone. Rapid oxygen consumption, nitrate reduction and dissolution of manganese confirmed anoxic conditions within the first filtration step, mimicking traditional bank filtration. Aeration with air led to suboxic conditions, whereas oxidation by pure oxygen and ozone led to fully oxic conditions throughout the second system. The sequential system resulted in an equal or better transformation of most TOrCs compared to the single step bank filtration system. Despite the fast oxygen consumption, acesulfame, iopromide, iomeprol and valsartan were degraded within the first infiltration step. The compounds benzotriazole, diclofenac, 4-Formylaminoantipyrine, gabapentin, metoprolol, valsartan acid and venlafaxine revealed a significantly enhanced removal in the systems with intermittent oxidation compared to the conventional treatment without aeration. Further improvement of benzotriazole and gabapentin removal by using pure oxygen confirmed potential oxygen limitation in the second column after aeration with air. Ozonation resulted in an enhanced removal of persistent compounds (i.e., carbamazepine, candesartan, olmesartan) and further increased the attenuation of gabapentin, methylbenzotriazole, benzotriazole, and venlafaxine. Diatrizoic acid revealed little degradation in an ozone–MAR hybrid system. Full article
(This article belongs to the Special Issue Water Quality Considerations for Managed Aquifer Recharge Systems)
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Open AccessEditor’s ChoiceArticle
Dynamics of Domestic Water Consumption in the Urban Area of the Kathmandu Valley: Situation Analysis Pre and Post 2015 Gorkha Earthquake
Water 2017, 9(3), 222; https://doi.org/10.3390/w9030222 - 17 Mar 2017
Cited by 14
Abstract
Information regarding domestic water consumption is vital, as the Kathmandu Valley will soon be implementing the Melamchi Water Supply Project; however, updated information on the current situation after the 2015 Gorkha Earthquake (GEQ) is still lacking. We investigated the dynamics of domestic water [...] Read more.
Information regarding domestic water consumption is vital, as the Kathmandu Valley will soon be implementing the Melamchi Water Supply Project; however, updated information on the current situation after the 2015 Gorkha Earthquake (GEQ) is still lacking. We investigated the dynamics of domestic water consumption pre- and post-GEQ. The piped water supply was short, and consumption varied widely across the Kathmandu Upatyaka Khanepani Limited (KUKL) branches and altitude. The reduction in piped, ground, and jar water consumption and the increase in tanker water consumption post-GEQ appeared to be due to the impact of the GEQ. However, the impact did not appear to be prominent on per capita water consumption, although it was reduced from 117 to 99 L post-GEQ. Piped, ground, and tanker water use were associated with an increase and jar water use was associated with a decrease in water consumption. Despite improvements in quantity, inequality in water consumption and inequity in affordability across wealth status was well established. This study suggests to KUKL the areas of priority where improvements to supply are required, and recommends an emphasis on resuming performance. Policy planners should consider the existing inequity in affordability, which is a major issue in the United Nations Sustainable Development Goals. Full article
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Open AccessEditor’s ChoiceArticle
Detection of Viable Bacteria during Sludge Ozonation by the Combination of ATP Assay with PMA-Miseq Sequencing
Water 2017, 9(3), 166; https://doi.org/10.3390/w9030166 - 26 Feb 2017
Cited by 18
Abstract
Using sludge obtained from municipal sewage treatment plants, the response of viable bacterial populations during the sludge ozonation process was investigated by a combination of adenosine triphosphate (ATP) assay and propidium monoazide (PMA)-Miseq sequencing. The ATP assay was first optimized for application on [...] Read more.
Using sludge obtained from municipal sewage treatment plants, the response of viable bacterial populations during the sludge ozonation process was investigated by a combination of adenosine triphosphate (ATP) assay and propidium monoazide (PMA)-Miseq sequencing. The ATP assay was first optimized for application on sludge samples by adjusting the sludge solid contents and reaction time. PMA-modified polymerase chain reaction (PCR) was also optimized by choosing the suitable final PMA concentration. The quantity and composition of viable bacterial populations during sludge ozonation were further elucidated using the optimized ATP and PMA-modified PCR methods. The results indicated that after the sludge was exposed to ozone (O3) at 135 mg·O3/g total suspended solids (TSS), the viable biomass displayed a substantial decrease, with a reduction rate reaching 70.89%. The composition of viable bacterial communities showed a faster succession, showing that an ozone dosage of 114 mg·O3/g TSS is enough to significantly change the viable bacterial population structure. Floc-forming genera, such as Zoogloea, Ferruginibacter, Thauera and Turneriella, are sensitive to ozonation, while the relative abundances of some functional bacterial genera, including SM1A02, Nitrospira and Candidatus Accumulibacter, remained constant or increased in the viable bacterial population during sludge ozonation, indicating that they are more resistant to ozonation. Full article
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Open AccessEditor’s ChoiceArticle
Machine Learning Algorithms for the Forecasting of Wastewater Quality Indicators
Water 2017, 9(2), 105; https://doi.org/10.3390/w9020105 - 09 Feb 2017
Cited by 31
Abstract
Stormwater runoff is often contaminated by human activities. Stormwater discharge into water bodies significantly contributes to environmental pollution. The choice of suitable treatment technologies is dependent on the pollutant concentrations. Wastewater quality indicators such as biochemical oxygen demand (BOD5), chemical oxygen demand (COD), [...] Read more.
Stormwater runoff is often contaminated by human activities. Stormwater discharge into water bodies significantly contributes to environmental pollution. The choice of suitable treatment technologies is dependent on the pollutant concentrations. Wastewater quality indicators such as biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solids (TSS), and total dissolved solids (TDS) give a measure of the main pollutants. The aim of this study is to provide an indirect methodology for the estimation of the main wastewater quality indicators, based on some characteristics of the drainage basin. The catchment is seen as a black box: the physical processes of accumulation, washing, and transport of pollutants are not mathematically described. Two models deriving from studies on artificial intelligence have been used in this research: Support Vector Regression (SVR) and Regression Trees (RT). Both the models showed robustness, reliability, and high generalization capability. However, with reference to coefficient of determination R2 and root‐mean square error, Support Vector Regression showed a better performance than Regression Tree in predicting TSS, TDS, and COD. As regards BOD5, the two models showed a comparable performance. Therefore, the considered machine learning algorithms may be useful for providing an estimation of the values to be considered for the sizing of the treatment units in absence of direct measures. Full article
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Open AccessEditor’s ChoiceArticle
Energy Recovery in Existing Water Networks: Towards Greater Sustainability
Water 2017, 9(2), 97; https://doi.org/10.3390/w9020097 - 08 Feb 2017
Cited by 42
Abstract
Analyses of possible synergies between energy recovery and water management are essential for achieving sustainable improvements in the performance of irrigation water networks. Improving the energy efficiency of water systems by hydraulic energy recovery is becoming an inevitable trend for energy conservation, emissions [...] Read more.
Analyses of possible synergies between energy recovery and water management are essential for achieving sustainable improvements in the performance of irrigation water networks. Improving the energy efficiency of water systems by hydraulic energy recovery is becoming an inevitable trend for energy conservation, emissions reduction, and the increase of profit margins as well as for environmental requirements. This paper presents the state of the art of hydraulic energy generation in drinking and irrigation water networks through an extensive review and by analyzing the types of machinery installed, economic and environmental implications of large and small hydropower systems, and how hydropower can be applied in water distribution networks (drinking and irrigation) where energy recovery is not the main objective. Several proposed solutions of energy recovery by using hydraulic machines increase the added value of irrigation water networks, which is an open field that needs to be explored in the near future. Full article
(This article belongs to the Special Issue Water Systems towards New Future Challenges)
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Open AccessEditor’s ChoiceArticle
Water Savings of Crop Redistribution in the United States
Water 2017, 9(2), 83; https://doi.org/10.3390/w9020083 - 30 Jan 2017
Cited by 11
Abstract
Demographic growth, changes in diet, and reliance on first-generation biofuels are increasing the human demand for agricultural products, thereby enhancing the human pressure on global freshwater resources. Recent research on the food-water nexus has highlighted how some major agricultural regions of the world [...] Read more.
Demographic growth, changes in diet, and reliance on first-generation biofuels are increasing the human demand for agricultural products, thereby enhancing the human pressure on global freshwater resources. Recent research on the food-water nexus has highlighted how some major agricultural regions of the world lack the water resources required to sustain current growth trends in crop production. To meet the increasing need for agricultural commodities with limited water resources, the water use efficiency of the agricultural sector must be improved. In this regard, recent work indicates that the often overlooked strategy of changing the crop distribution within presently cultivated areas offers promise. Here we investigate the extent to which water in the United States could be saved while improving yields simply by replacing the existing crops with more suitable ones. We propose crop replacement criteria that achieve this goal while preserving crop diversity, economic value, nitrogen fixation, and food protein production. We find that in the United States, these criteria would greatly improve calorie (+46%) and protein (+34%) production and economic value (+208%), with 5% water savings with respect to the present crop distribution. Interestingly, greater water savings could be achieved in water-stressed agricultural regions of the US such as California (56% water savings), and other western states. Full article
(This article belongs to the Special Issue Water Footprint Assessment)
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Open AccessEditor’s ChoiceArticle
Comparison of Multi-Criteria Decision Support Methods for Integrated Rehabilitation Prioritization
Water 2017, 9(2), 68; https://doi.org/10.3390/w9020068 - 24 Jan 2017
Cited by 37
Abstract
The decisions taken in rehabilitation planning for the urban water networks will have a long lasting impact on the functionality and quality of future services provided by urban infrastructure. These decisions can be assisted by different approaches ranging from linear depreciation for estimating [...] Read more.
The decisions taken in rehabilitation planning for the urban water networks will have a long lasting impact on the functionality and quality of future services provided by urban infrastructure. These decisions can be assisted by different approaches ranging from linear depreciation for estimating the economic value of the network over using a deterioration model to assess the probability of failure or the technical service life to sophisticated multi-criteria decision support systems. Subsequently, the aim of this paper is to compare five available multi-criteria decision-making (MCDM) methods (ELECTRE, AHP, WSM, TOPSIS, and PROMETHEE) for the application in an integrated rehabilitation management scheme for a real world case study and analyze them with respect to their suitability to be used in integrated asset management of water systems. The results of the different methods are not equal. This occurs because the chosen score scales, weights and the resulting distributions of the scores within the criteria do not have the same impact on all the methods. Independently of the method used, the decision maker must be familiar with its strengths but also weaknesses. Therefore, in some cases, it would be rational to use one of the simplest methods. However, to check for consistency and increase the reliability of the results, the application of several methods is encouraged. Full article
(This article belongs to the Special Issue Synergies in Urban Water Infrastructure Modeling)
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Review

Jump to: Research, Other

Open AccessEditor’s ChoiceReview
The Use of Algae and Fungi for Removal of Pharmaceuticals by Bioremediation and Biosorption Processes: A Review
Water 2019, 11(8), 1555; https://doi.org/10.3390/w11081555 - 27 Jul 2019
Abstract
The occurrence and fate of pharmaceuticals in the aquatic environment is recognized as one of the emerging issues in environmental chemistry. Conventional wastewater treatment plants (WWTPs) are not designed to remove pharmaceuticals (and their metabolites) from domestic wastewaters. The treatability of pharmaceutical compounds [...] Read more.
The occurrence and fate of pharmaceuticals in the aquatic environment is recognized as one of the emerging issues in environmental chemistry. Conventional wastewater treatment plants (WWTPs) are not designed to remove pharmaceuticals (and their metabolites) from domestic wastewaters. The treatability of pharmaceutical compounds in WWTPs varies considerably depending on the type of compound since their biodegradability can differ significantly. As a consequence, they may reach the aquatic environment, directly or by leaching of the sludge produced by these facilities. Currently, the technologies under research for the removal of pharmaceuticals, namely membrane technologies and advanced oxidation processes, have high operation costs related to energy and chemical consumption. When chemical reactions are involved, other aspects to consider include the formation of harmful reaction by-products and the management of the toxic sludge produced. Research is needed in order to develop economic and sustainable treatment processes, such as bioremediation and biosorption. The use of low-cost materials, such as biological matrices (e.g., algae and fungi), has advantages such as low capital investment, easy operation, low operation costs, and the non-formation of degradation by-products. An extensive review of existing research on this subject is presented. Full article
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Open AccessEditor’s ChoiceReview
Risk-Yuck Factor Nexus in Reclaimed Wastewater for Irrigation: Comparing Farmers’ Attitudes and Public Perception
Water 2019, 11(2), 187; https://doi.org/10.3390/w11020187 - 22 Jan 2019
Cited by 1
Abstract
The successes and failures of water reuse schemes are shaped by complex interrelationships between technological, economic, and socio-political factors. However, it has long been recognized that the main challenges to more effective water management are largely social rather than technical. This article reviews [...] Read more.
The successes and failures of water reuse schemes are shaped by complex interrelationships between technological, economic, and socio-political factors. However, it has long been recognized that the main challenges to more effective water management are largely social rather than technical. This article reviews the recent literature (2007–2017) to analyze driving factors associated with farmers’ concerns and public perception of reclaimed wastewater for irrigation. The aim of the paper is to synthetize how both environmental and health risks and the yuck factor could be addressed in order to promote mutual understanding between farmers and the public. Results show: (1) how farmers and the public perceive environmental and health risks in a similar way, (2) how the yuck factor is more noticeable for the public than farmers, and (3) how constructed wetlands, reclaimed water exchange consortiums, product certification, and direct site visits to water reuse infrastructure could be promoted in order to foster understanding between farmers and the public. The article concludes by providing key research questions for managers and public authorities relating to how to focus on the study of technical and social issues related to water reuse. Full article
(This article belongs to the Special Issue Wastewater Treatment: Review, Key Challenges, and New Perspectives)
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Open AccessEditor’s ChoiceReview
Assessment of Sulfate Radical-Based Advanced Oxidation Processes for Water and Wastewater Treatment: A Review
Water 2018, 10(12), 1828; https://doi.org/10.3390/w10121828 - 11 Dec 2018
Cited by 14
Abstract
High oxidation potential as well as other advantages over other tertiary wastewater treatments have led in recent years to a focus on the development of advanced oxidation processes based on sulfate radicals (SR-AOPs). These radicals can be generated from peroxymonosulfate (PMS) and persulfate [...] Read more.
High oxidation potential as well as other advantages over other tertiary wastewater treatments have led in recent years to a focus on the development of advanced oxidation processes based on sulfate radicals (SR-AOPs). These radicals can be generated from peroxymonosulfate (PMS) and persulfate (PS) through various activation methods such as catalytic, radiation or thermal activation. This review manuscript aims to provide a state-of-the-art overview of the different methods for PS and PMS activaton, as well as the different applications of this technology in the field of water and wastewater treatment. Although its most widespread application is the elimination of micropollutants, its use for the disinfection of wastewater is gaining increasing interest. In addition, the possibility of combining this technology with ultrafiltration membranes to improve the water quality and lifespan of the membranes has also been discussed. Finally, a brief economic analysis of this technology has been undertaken and the different attempts made to implement it at full-scale have been summarized. As a result, this review tries to be useful for all those people working in that area. Full article
(This article belongs to the Section Water and Wastewater Treatment)
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Open AccessEditor’s ChoiceReview
Flood Prediction Using Machine Learning Models: Literature Review
Water 2018, 10(11), 1536; https://doi.org/10.3390/w10111536 - 27 Oct 2018
Cited by 51
Abstract
Floods are among the most destructive natural disasters, which are highly complex to model. The research on the advancement of flood prediction models contributed to risk reduction, policy suggestion, minimization of the loss of human life, and reduction of the property damage associated [...] Read more.
Floods are among the most destructive natural disasters, which are highly complex to model. The research on the advancement of flood prediction models contributed to risk reduction, policy suggestion, minimization of the loss of human life, and reduction of the property damage associated with floods. To mimic the complex mathematical expressions of physical processes of floods, during the past two decades, machine learning (ML) methods contributed highly in the advancement of prediction systems providing better performance and cost-effective solutions. Due to the vast benefits and potential of ML, its popularity dramatically increased among hydrologists. Researchers through introducing novel ML methods and hybridizing of the existing ones aim at discovering more accurate and efficient prediction models. The main contribution of this paper is to demonstrate the state of the art of ML models in flood prediction and to give insight into the most suitable models. In this paper, the literature where ML models were benchmarked through a qualitative analysis of robustness, accuracy, effectiveness, and speed are particularly investigated to provide an extensive overview on the various ML algorithms used in the field. The performance comparison of ML models presents an in-depth understanding of the different techniques within the framework of a comprehensive evaluation and discussion. As a result, this paper introduces the most promising prediction methods for both long-term and short-term floods. Furthermore, the major trends in improving the quality of the flood prediction models are investigated. Among them, hybridization, data decomposition, algorithm ensemble, and model optimization are reported as the most effective strategies for the improvement of ML methods. This survey can be used as a guideline for hydrologists as well as climate scientists in choosing the proper ML method according to the prediction task. Full article
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Open AccessEditor’s ChoiceReview
Explaining Water Pricing through a Water Security Lens
Water 2018, 10(9), 1173; https://doi.org/10.3390/w10091173 - 01 Sep 2018
Cited by 3
Abstract
Can water security serve as a platform for developing a long-term solution to ongoing water crises? Many regions around the world are experiencing severe water problems, including water scarcity, water-borne diseases, water-related natural hazards, and water conflicts. These issues are expected to increase [...] Read more.
Can water security serve as a platform for developing a long-term solution to ongoing water crises? Many regions around the world are experiencing severe water problems, including water scarcity, water-borne diseases, water-related natural hazards, and water conflicts. These issues are expected to increase and intensify in the future. Both developed and developing economies face a water supply and demand imbalance that will potentially influence their water pricing structures. Institutions and policies that govern the pricing of this natural capital remain crucial for driving food production and providing services. The complex and multifaceted issues of sustainable water management call for a standard set of tools that can capture and create desired water security scenarios. Water pricing is an important contributing factor for achieving these scenarios. In this paper, we analyze how water pricing can be used as a tool to enact the water security agenda. This paper addresses these issues from three facets: (1) Economic aspects—the multiple processes through which water is conceptualized and priced; (2) analysis of water pricing considering its effect in water consumption; and (3) arguments for assessing the potential of water pricing as a tool to appraise water security. Full article
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Open AccessEditor’s ChoiceReview
Artificial Aquatic Ecosystems
Water 2018, 10(8), 1096; https://doi.org/10.3390/w10081096 - 17 Aug 2018
Cited by 7
Abstract
As humans increasingly alter the surface geomorphology of the Earth, a multitude of artificial aquatic systems have appeared, both deliberately and accidentally. Human modifications to the hydroscape range from alteration of existing waterbodies to construction of new ones. The extent of these systems [...] Read more.
As humans increasingly alter the surface geomorphology of the Earth, a multitude of artificial aquatic systems have appeared, both deliberately and accidentally. Human modifications to the hydroscape range from alteration of existing waterbodies to construction of new ones. The extent of these systems makes them important and dynamic components of modern landscapes, but their condition and provisioning of ecosystem services by these systems are underexplored, and likely underestimated. Instead of accepting that artificial ecosystems have intrinsically low values, environmental scientists should determine what combination of factors, including setting, planning and construction, subsequent management and policy, and time, impact the condition of these systems. Scientists, social scientists, and policymakers should more thoroughly evaluate whether current study and management of artificial aquatic systems is based on the actual ecological condition of these systems, or judged differently, due to artificiality, and consider resultant possible changes in goals for these systems. The emerging recognition and study of artificial aquatic systems presents an exciting and important opportunity for science and society. Full article
(This article belongs to the Special Issue 10th Anniversary of Water)
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Open AccessEditor’s ChoiceReview
Advances in Water Use Efficiency in Agriculture: A Bibliometric Analysis
Water 2018, 10(4), 377; https://doi.org/10.3390/w10040377 - 25 Mar 2018
Cited by 18
Abstract
Water use efficiency in agriculture (WUEA) has become a priority given increasing limitations on hydric resources. As a result, this area of research has increased in importance, becoming one of the most prolific lines of study. The main aim of this study was [...] Read more.
Water use efficiency in agriculture (WUEA) has become a priority given increasing limitations on hydric resources. As a result, this area of research has increased in importance, becoming one of the most prolific lines of study. The main aim of this study was to present a review of worldwide WUEA research over the last 30 years. A bibliometric analysis was developed based on the Scopus database. The sample included 6063 articles. The variables analyzed were: articles per year, category, journal, country, institution, author, and keyword. The results indicate that a remarkable growth in the number of articles published per year is occurring. The main category is environmental science and the main journal Agricultural Water Management. The countries with the highest number of articles were China, the United States of America, and India. The institution that published the most articles was the Chinese Academy of Sciences and the authors from China also were the most productive. The most frequently used keywords were irrigation, crop yield, water supply, and crops. The findings of this study can assist researchers in this field by providing an overview of worldwide research. Full article
(This article belongs to the Special Issue Advances in Agriculture Water Efficiency)
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Open AccessEditor’s ChoiceReview
Lost in Optimisation of Water Distribution Systems? A Literature Review of System Design
Water 2018, 10(3), 307; https://doi.org/10.3390/w10030307 - 13 Mar 2018
Cited by 17
Abstract
Optimisation of water distribution system design is a well-established research field, which has been extremely productive since the end of the 1980s. Its primary focus is to minimise the cost of a proposed pipe network infrastructure. This paper reviews in a systematic manner [...] Read more.
Optimisation of water distribution system design is a well-established research field, which has been extremely productive since the end of the 1980s. Its primary focus is to minimise the cost of a proposed pipe network infrastructure. This paper reviews in a systematic manner articles published over the past three decades, which are relevant to the design of new water distribution systems, and the strengthening, expansion and rehabilitation of existing water distribution systems, inclusive of design timing, parameter uncertainty, water quality, and operational considerations. It identifies trends and limits in the field, and provides future research directions. Exclusively, this review paper also contains comprehensive information from over one hundred and twenty publications in a tabular form, including optimisation model formulations, solution methodologies used, and other important details. Full article
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Open AccessEditor’s ChoiceReview
A Review of the Integrated Effects of Changing Climate, Land Use, and Dams on Mekong River Hydrology
Water 2018, 10(3), 266; https://doi.org/10.3390/w10030266 - 03 Mar 2018
Cited by 27
Abstract
The ongoing and proposed construction of large-scale hydropower dams in the Mekong river basin is a subject of intense debate and growing international concern due to the unprecedented and potentially irreversible impacts these dams are likely to have on the hydrological, agricultural, and [...] Read more.
The ongoing and proposed construction of large-scale hydropower dams in the Mekong river basin is a subject of intense debate and growing international concern due to the unprecedented and potentially irreversible impacts these dams are likely to have on the hydrological, agricultural, and ecological systems across the basin. Studies have shown that some of the dams built in the tributaries and the main stem of the upper Mekong have already caused basin-wide impacts by altering the magnitude and seasonality of flows, blocking sediment transport, affecting fisheries and livelihoods of downstream inhabitants, and changing the flood pulse to the Tonle Sap Lake. There are hundreds of additional dams planned for the near future that would result in further changes, potentially causing permanent damage to the highly productive agricultural systems and fisheries, as well as the riverine and floodplain ecosystems. Several studies have examined the potential impacts of existing and planned dams but the integrated effects of the dams when combined with the adverse hydrologic consequences of climate change remain largely unknown. Here, we provide a detailed review of the existing literature on the changes in climate, land use, and dam construction and the resulting impacts on hydrological, agricultural, and ecological systems across the Mekong. The review provides a basis to better understand the effects of climate change and accelerating human water management activities on the coupled hydrological-agricultural-ecological systems, and identifies existing challenges to study the region’s Water, Energy, and Food (WEF) nexus with emphasis on the influence of future dams and projected climate change. In the last section, we synthesize the results and highlight the urgent need to develop integrated models to holistically study the coupled natural-human systems across the basin that account for the impacts of climate change and water infrastructure development. This review provides a framework for future research in the Mekong, including studies that integrate hydrological, agricultural, and ecological modeling systems. 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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Open AccessEditor’s ChoiceReview
Evaluating Stream Restoration Projects: What Do We Learn from Monitoring?
Water 2017, 9(3), 174; https://doi.org/10.3390/w9030174 - 28 Feb 2017
Cited by 15
Abstract
Two decades since calls for stream restoration projects to be scientifically assessed, most projects are still unevaluated, and conducted evaluations yield ambiguous results. Even after these decades of investigation, do we know how to define and measure success? We systematically reviewed 26 studies [...] Read more.
Two decades since calls for stream restoration projects to be scientifically assessed, most projects are still unevaluated, and conducted evaluations yield ambiguous results. Even after these decades of investigation, do we know how to define and measure success? We systematically reviewed 26 studies of stream restoration projects that used macroinvertebrate indicators to assess the success of habitat heterogeneity restoration projects. All 26 studies were previously included in two meta-analyses that sought to assess whether restoration programs were succeeding. By contrast, our review focuses on the evaluations themselves, and asks what exactly we are measuring and learning from these evaluations. All 26 studies used taxonomic diversity, richness, or abundance of invertebrates as biological measures of success, but none presented explicit arguments why those metrics were relevant measures of success for the restoration projects. Although changes in biodiversity may reflect overall ecological condition at the regional or global scale, in the context of reach-scale habitat restoration, more abundance and diversity may not necessarily be better. While all 26 studies sought to evaluate the biotic response to habitat heterogeneity enhancement projects, about half of the studies (46%) explicitly measured habitat alteration, and 31% used visual estimates of grain size or subjectively judged ‘habitat quality’ from protocols ill-suited for the purpose. Although the goal of all 26 projects was to increase habitat heterogeneity, 31% of the studies either sampled only riffles or did not specify the habitats sampled. One-third of the studies (35%) used reference ecosystems to define target conditions. After 20 years of stream restoration evaluation, more work remains for the restoration community to identify appropriate measures of success and to coordinate monitoring so that evaluations are at a scale capable of detecting ecosystem change. Full article

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Open AccessFeature PaperEditor’s ChoiceCommentary
Making the Case for a Female-Friendly Toilet
Water 2018, 10(9), 1193; https://doi.org/10.3390/w10091193 - 05 Sep 2018
Cited by 5
Abstract
Inadequate access to a private, comfortable, and well-located toilet remains a critical challenge for many girls and women around the world. This issue is especially acute for girls and women living in densely populated urban slums, displacement camps, and informal settlements, often resulting [...] Read more.
Inadequate access to a private, comfortable, and well-located toilet remains a critical challenge for many girls and women around the world. This issue is especially acute for girls and women living in densely populated urban slums, displacement camps, and informal settlements, often resulting in anxiety, embarrassment, discomfort, and gender-based violence. The unique sanitation needs of girls and women are rarely accounted for during the design and construction of toilet facilities, including needs related to their physiology, reproductive health processes, prevalent social norms, and their heightened vulnerability to violence. It is critical that a new norm be developed regarding the design of female-friendly toilets which better enables girls and women to feel confident, safe, and dignified while managing their daily sanitation needs. This includes adopting specific design measures which account for their menstrual hygiene, personal safety, and dignity-related needs. Ultimately, an enhanced dialogue must take place among designers, policy makers, water, sanitation, and hygiene (WASH) practitioners, and other relevant actors, in addition to the target female users themselves, about how to adapt toilets in a range of development and emergency contexts and operations to better address these critical needs of girls and women. Full article
(This article belongs to the Special Issue Water, Sanitation, and Hygiene in Humanitarian Contexts)
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