Open AccessArticle
Understanding and Control of Biopolymer Fouling in Ultrafiltration of Different Water Types
Water 2017, 9(4), 298; doi:10.3390/w9040298 (registering DOI) -
Abstract
The present work focuses on understanding and control of biopolymer fouling in ultrafiltration of a typical surface water and nearby secondary effluent for direct and indirect portable use. Characterization results show that both kinds of biopolymers are of similar molecular weight. Longer than
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The present work focuses on understanding and control of biopolymer fouling in ultrafiltration of a typical surface water and nearby secondary effluent for direct and indirect portable use. Characterization results show that both kinds of biopolymers are of similar molecular weight. Longer than one year water quality monitoring results show that the C/N ratio in the secondary effluent biopolymers was relatively constant at around 4.8, while that in the surface water macromolecules fluctuated at around 6.9. Under a similar mass load, the investigated secondary effluent biopolymers lead to hydraulic resistance slightly higher than that caused by filtering surface water macromolecules; however, the correspondingly formed fouling is significantly less reversible by hydraulic backwashing. The quantity of the nitrogenous biopolymers in the secondary effluent demonstrated a strong correlation with the extent of the irreversible fouling in ultrafiltration (UF), while that from the surface water did not. In membrane fouling cleaning tests, certain detergent demonstrated high efficiency in removing the irreversible fouling after UF of the secondary effluent, but presented no effect in eliminating fouling caused by the surface water foulants. In-line coagulation using FeCl3 prior to UF was shown as an effective fouling control method, but the effect depends heavily on the type of feed water. Full article
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Open AccessArticle
Pluvial Flooding in European Cities—A Continental Approach to Urban Flood Modelling
Water 2017, 9(4), 296; doi:10.3390/w9040296 (registering DOI) -
Abstract
Pluvial flooding is caused by localized intense rainfall and the flood models used to assess it are normally applied on a city (or part of a city) scale using local rainfall records and a high resolution digital elevation model (DEM). Here, we attempt
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Pluvial flooding is caused by localized intense rainfall and the flood models used to assess it are normally applied on a city (or part of a city) scale using local rainfall records and a high resolution digital elevation model (DEM). Here, we attempt to model pluvial flooding on a continental scale and calculate the percentage of area flooded for all European cities for a 10-year return period for hourly rainfall (RP10). Difficulties in obtaining hourly rainfall records compromise the estimation of each city RP10 and the Europe-wide DEM spatial resolution is low relative to those typically used for individual case-studies. Nevertheless, the modelling capabilities and necessary computing power make this type of continental study now possible. This is a first attempt at continental city flooding modelling and our methodology was designed so that our results can easily be updated as better/more data becomes available. The results for each city depend on the interplay of rainfall intensity, the elevation map of the city and the flow paths that are created. In general, cities with lower percentage of city flooded are in the north and west coastal areas of Europe, while the higher percentages are seen in continental and Mediterranean areas. Full article
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Open AccessArticle
Re-Staging La Rasgioni: Lessons Learned from Transforming a Traditional Form of Conflict Resolution to Engage Stakeholders in Agricultural Water Governance
Water 2017, 9(4), 297; doi:10.3390/w9040297 (registering DOI) -
Abstract
This paper presents an informal process inspired by a public practice of conflict mediation used until a few decades ago in Gallura (NE Sardinia, Italy), named La Rasgioni (The Reason). The aim is twofold: (i) to introduce an innovative method that translates the
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This paper presents an informal process inspired by a public practice of conflict mediation used until a few decades ago in Gallura (NE Sardinia, Italy), named La Rasgioni (The Reason). The aim is twofold: (i) to introduce an innovative method that translates the complexity of water-related conflicts into a “dialogical tool”, aimed at enhancing social learning by adopting theatrical techniques; and (ii) to report the outcomes that emerged from the application of this method in Arborea, the main dairy cattle district and the only nitrate-vulnerable zone in Sardinia, to mediate contrasting positions between local entrepreneurs and representatives of the relevant institutions. We discuss our results in the light of four pillars, adopted as research lenses in the International research Project CADWAGO (Climate Change Adaptation and Water Governance), which consider the specific “social–ecological” components of the Arborea system, climate change adaptability in water governance institutions and organizations, systemic governance (relational) practices, and governance learning. The combination of the four CADWAGO pillars and La Rasgioni created an innovative dialogical space that enabled stakeholders and researchers to collectively identify barriers and opportunities for effective governance practices. Potential wider implications and applications of La Rasgioni process are also discussed in the paper. Full article
Open AccessArticle
Adaptation of Cascade Hydropower Station Scheduling on A Headwater Stream of the Yangtze River under Changing Climate Conditions
Water 2017, 9(4), 293; doi:10.3390/w9040293 (registering DOI) -
Abstract
Cascade hydropower stations are effective in water resource utilization, regional water allocation, and flood risk management. Under changing climate conditions, water resources would experience complex temporal and spatial changes, which may lead to various issues relating to flood control and water resource management,
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Cascade hydropower stations are effective in water resource utilization, regional water allocation, and flood risk management. Under changing climate conditions, water resources would experience complex temporal and spatial changes, which may lead to various issues relating to flood control and water resource management, and challenge the existing optimal scheduling of cascade hydropower stations. It is thus important to conduct a study on cascade hydropower station scheduling under changing climate conditions. In this study, the Jinsha River rainfall–discharge statistical model is developed based on the statistical relationship between meteorological and runoff indicators. Validation results indicate that the developed model is capable of generating satisfactory simulation results and thus can be used for future Jinsha River runoff projection under climate change. Meanwhile, the Providing Regional Climates for Impacts Studies (PRECIS) is run to project future rainfall in the Jinsha River basin under two General Circulation Models (ECHAM5 and HadAM3P), two scenarios (A1B and B2), and four periods (1961–1990, 1991–2020, 2021–2050, and 2051–2099). The regional climate modeling data are analyzed and then fed into the Jinsha hydrological model to analyze the trends of future discharge at Xiangjiaba Hydro Station. Adaptive scheduling strategies for cascade hydropower stations are discussed based on the future inflow trend analysis and current flood scheduling mode. It is suggested that cascade hydropower stations could be operated at flood limited water level (FLWL) during 2021–2099. In addition, the impoundment of cascade hydropower stations should be properly delayed during the post-flood season in response to the possible occurrence of increased and extended inflow in wet seasons. Full article
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Open AccessArticle
Performance and Yeast Tracking in A Full-Scale Oil-Containing Paromomycin Production Wastewater Treatment System Using Yeast
Water 2017, 9(4), 295; doi:10.3390/w9040295 (registering DOI) -
Abstract
High residual oil content in antibiotic production waste mother liquor makes solid–liquid separation of fermentation residue and wastewater difficult. A yeast-based pretreatment process was established for the removal of oil and promotion of solid–liquid separation in antibiotic production wastewater treatment systems. Six yeast
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High residual oil content in antibiotic production waste mother liquor makes solid–liquid separation of fermentation residue and wastewater difficult. A yeast-based pretreatment process was established for the removal of oil and promotion of solid–liquid separation in antibiotic production wastewater treatment systems. Six yeast strains acquired from different sources were inoculated into sequencing batch reactors (SBR) in pilot and full-scale wastewater treatment plants. Oil removal rates were 85.0%–92.0% and 61.4%–74.2%, and sludge settling velocities (SV) were 16.6%–21.3% and 22.6%–32.0% for the pilot and full-scale operations, respectively. 18S rRNA gene clone libraries were established to track the fates of the inoculated yeasts, which showed that Candida tropicalis was dominant in the full-scale plant. The fungi and bacteria gene copy ratio determined by quantitative polymerase chain reaction was 14.87 during stable field operation, indicating that yeast successfully colonized. Both the pilot and full-scale studies proved that yeast can be used to promote solid–liquid separation, and yeast systems are a stable and effective method for oil-containing fermentation antibiotic production wastewater pretreatment. Full article
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Open AccessArticle
Comparison of IMERG Level-3 and TMPA 3B42V7 in Estimating Typhoon-Related Heavy Rain
Water 2017, 9(4), 276; doi:10.3390/w9040276 (registering DOI) -
Abstract
Typhoon-related heavy rain has unique structures in both time and space, and use of satellite-retrieved products to delineate the structure of heavy rain is especially meaningful for early warning systems and disaster management. This study compares two newly-released satellite products from the Integrated
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Typhoon-related heavy rain has unique structures in both time and space, and use of satellite-retrieved products to delineate the structure of heavy rain is especially meaningful for early warning systems and disaster management. This study compares two newly-released satellite products from the Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (IMERG final run) and the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA 3B42V7) with daily rainfall observed by ground rain gauges. The comparison is implemented for eight typhoons over the coastal region of China for a two-year period from 2014 to 2015. The results show that all correlation coefficients (CCs) of both IMERG and TMPA for the investigated typhoon events are significant at the 0.01 level, but they tend to underestimate the heavy rainfall, especially around the storm center. The IMERG final run exhibits an overall better performance than TMPA 3B42V7. It is also shown that both products have a better applicability (i.e., a smaller absolute relative bias) when rain intensities are within 20–40 and 80–100 mm/day than those of 40–80 mm/day and larger than 100 mm/day. In space, they generally have the best applicability within the range of 50–100 km away from typhoon tracks, and have the worst applicability beyond the 300-km range. The results are beneficial to understand the errors of satellite data in operational applications, such as storm monitoring and hydrological modeling. Full article
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Open AccessArticle
Numerical Simulation of Soil Evaporation with Sand Mulching and Inclusion
Water 2017, 9(4), 294; doi:10.3390/w9040294 (registering DOI) -
Abstract
A model of unsaturated soil-water movement using a prediction model of basic physical soil properties for calculating correlation functions was developed using VADOSE/W. The reliability of the model was assessed by comparing the results with those of a soil-column test. Coefficients of determination,
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A model of unsaturated soil-water movement using a prediction model of basic physical soil properties for calculating correlation functions was developed using VADOSE/W. The reliability of the model was assessed by comparing the results with those of a soil-column test. Coefficients of determination, R2, between the simulated and the measured daily evaporation for sand-mulch thicknesses of 0 (control, CK), 1.7, 3.6 and 5.7 cm were 0.8270, 0.8214, 0.8589 and 0.9851, respectively. R2, between the simulated and measured cumulative evaporation for mulch thicknesses of 0, 1.7, 3.6 and 5.7 cm were 0.9755, 0.9994, 0.9997 and 0.9983, respectively. The fits were, thus, good, verifying the reliability of the model. The program accurately predicted the distribution of cumulative evaporation and volumetric water content during evaporation from a soil column with mulch thicknesses of 1, 1.3, 1.5, 1.7, 2, 3, 5 cm and depths of sand inclusion thick of 0, 5, 10 and 15 cm for 20 days. Cumulative evaporation of sand inclusion was lower than in CK. Cumulative evaporation was independent of the mulch thickness and depended only on the depth of the inclusion: the deeper the inclusion, the higher the evaporation. The best mulch thickness was 5 cm, and the best inclusion depth was 5 cm. This study offers a new method to study the evaporation process with sand mulching and inclusion, which can provide guidance for improving the utilization efficiency of soil water. Full article
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Open AccessArticle
Unsteady State Water Level Analysis for Discharge Hydrograph Estimation in Rivers with Torrential Regime: The Case Study of the February 2016 Flood Event in the Crati River, South Italy
Water 2017, 9(4), 288; doi:10.3390/w9040288 -
Abstract
Discharge hydrograph estimation during floods, in rivers with torrential regime, is often based on the use of rating curves extrapolated from very low stage–discharge measurements. To get a more reliable estimation, a reverse flow routing problem is solved using water level data measured
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Discharge hydrograph estimation during floods, in rivers with torrential regime, is often based on the use of rating curves extrapolated from very low stage–discharge measurements. To get a more reliable estimation, a reverse flow routing problem is solved using water level data measured in two gauged stations several kilometers from each other. Validation of the previous analysis carried out on the flood event of February 2016 at the Europa Bridge and Castiglione Scalo sections of the Crati River (Cosenza, Italy) is based on the use of ‘soft’ discharge measurement data and the comparison of the water level data computed in the downstream gauged section by three different hydraulic models with the ‘hard’ available water level measures. Results confirm that the 1D diffusive model provides more reliable results than the 1D complete one and no significant improvement is gained by the use of a more computationally demanding 2D model. Full article
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Open AccessArticle
Possibilities of Using Low Quality Digital Elevation Models of Floodplains in Hydraulic Numerical Models
Water 2017, 9(4), 283; doi:10.3390/w9040283 -
Abstract
The paper presents a method for the correction of low quality DEMs, based on aerial photographs, for use in 2D flood modeling. The proposed method was developed and tested on the example of the floodplain of the Warta River, which is the third
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The paper presents a method for the correction of low quality DEMs, based on aerial photographs, for use in 2D flood modeling. The proposed method was developed and tested on the example of the floodplain of the Warta River, which is the third biggest river in Poland. The correction of DEM is based on a series of a small number of measurements using GPS-RTK, which enable calculations of the global statistics like mean error (ME), root mean square error (RMSE) and standard deviation (SD). The impact of DEM accuracy was estimated by using a 2D numerical model. The calculated values of flow velocities, inundation area and volume of floodplain for each tested DEM were compared. The analyses indicate that, after the correction procedure, the predictions of corrected DEM based on poor quality data is in good quantitative and qualitative agreement with the referenced LIDAR DEM. The proposed method may be applied in the areas for which high resolution DEMs based on LIDAR data are not available. Full article
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Open AccessArticle
Modeling Coupled Water and Heat Transport in the Root Zone of Winter Wheat under Non-Isothermal Conditions
Water 2017, 9(4), 290; doi:10.3390/w9040290 -
Abstract
Temperature is an integral part of soil quality in terms of moisture content; coupling between water and heat can render a soil fertile, and plays a role in water conservation. Although it is widely recognized that both water and heat transport are fundamental
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Temperature is an integral part of soil quality in terms of moisture content; coupling between water and heat can render a soil fertile, and plays a role in water conservation. Although it is widely recognized that both water and heat transport are fundamental factors in the quantification of soil mass and energy balance, their computation is still limited in most models or practical applications in the root zone under non-isothermal conditions. This research was conducted to: (a) implement a fully coupled mathematical model that contains the full coupled process of soil water and heat transport with plants focused on the influence of temperature gradient on soil water redistribution and on the influence of change in soil water movement on soil heat flux transport; (b) verify the mathematical model with detailed field monitoring data; and (c) analyze the accuracy of the model. Results show the high accuracy of the model in predicting the actual changes in soil water content and temperature as a function of time and soil depth. Moreover, the model can accurately reflect changes in soil moisture and heat transfer in different periods. With only a few empirical parameters, the proposed model will serve as guide in the field of surface irrigation. Full article
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Open AccessArticle
A Multi-Criteria Decision Analysis System for Prioritizing Sites and Types of Low Impact Development Practices: Case of Korea
Water 2017, 9(4), 291; doi:10.3390/w9040291 -
Abstract
This study developed a multi-criteria decision analysis (MCDA) framework to prioritize sites and types of low impact development (LID) practices. This framework was systemized as a web-based system coupled with the Storm Water Management Model (SWMM). Using TOPSIS method, which is a type
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This study developed a multi-criteria decision analysis (MCDA) framework to prioritize sites and types of low impact development (LID) practices. This framework was systemized as a web-based system coupled with the Storm Water Management Model (SWMM). Using TOPSIS method, which is a type of MCDA method, multiple types and sites of designated LID practices are prioritized. This system is named the Water Management Prioritization Module (WMPM). WMPM can simultaneously determine the priority of multiple LID types and sites. In this study, an infiltration trench and permeable pavement were considered for multiple sub-catchments in South Korea to demonstrate the WMPM procedures. The TOPSIS method was manually incorporated to select the vulnerable target sub-catchments and to prioritize the LID planning scenarios for multiple types and sites considering social, hydrologic and physical-geometric factors. In this application, the Delphi method and entropy theory were used to determine the subjective and objective weights, respectively. Full article
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Open AccessArticle
Assessment of Social Vulnerability to Flood in Urban Côte d’Ivoire Using the MOVE Framework
Water 2017, 9(4), 292; doi:10.3390/w9040292 -
Abstract
Coupled with poor urban development, the increasing urban population of many Sub-Saharan African countries is subject to recurrent severe flooding episodes. In response to these flood events, while the focus is often put on slums and precarious urban settings, the social implications of
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Coupled with poor urban development, the increasing urban population of many Sub-Saharan African countries is subject to recurrent severe flooding episodes. In response to these flood events, while the focus is often put on slums and precarious urban settings, the social implications of these floods affect a variety of social classes. Presenting a case study of Cocody, a district of Abidjan, Côte d’Ivoire, known to have the country’s highest number of flood-impacted people, this paper evaluates the social vulnerability of urban Côte d’Ivoire to flooding using the MOVE framework. The MOVE framework (Method for the Improvement of Vulnerability Assessment in Europe) has successfully been used in European contexts to assess social vulnerability of urban areas to geo-environmental disasters such floods. It helped assess the major factors involved in the social vulnerability to urban flooding and to have a good appreciation of the spatial distribution of areas that are vulnerable to urban flood. By taking this framework to the local context, relevant indicators were developed and GIS applications were used to assess spatially the relative social vulnerability of Cocody sub-districts to urban flooding. The results revealed that many sub-districts of Cocody are highly vulnerable to urban floods. Exposure and susceptibility are components that are found to have high influence on vulnerability to flood hazard in the district of Cocody. Their respective indicators need to be addressed properly in order to increase residents’ resilience to urban flooding. The MOVE theoretical framework can be applied in Africa by contextualizing the vulnerability by using local indicators. Full article
Open AccessFeature PaperArticle
Evaluation of the Water Cycle in the European COSMO-REA6 Reanalysis Using GRACE
Water 2017, 9(4), 289; doi:10.3390/w9040289 -
Abstract
Precipitation and evapotranspiration, and in particular the precipitation minus evapotranspiration deficit (PE), are climate variables that may be better represented in reanalyses based on numerical weather prediction (NWP) models than in other datasets. PE provides essential information
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Precipitation and evapotranspiration, and in particular the precipitation minus evapotranspiration deficit (PE), are climate variables that may be better represented in reanalyses based on numerical weather prediction (NWP) models than in other datasets. PE provides essential information on the interaction of the atmosphere with the land surface, which is of fundamental importance for understanding climate change in response to anthropogenic impacts. However, the skill of models in closing the atmospheric-terrestrial water budget is limited. Here, total water storage estimates from the Gravity Recovery and Climate Experiment (GRACE) mission are used in combination with discharge data for assessing the closure of the water budget in the recent high-resolution Consortium for Small-Scale Modelling 6-km Reanalysis (COSMO-REA6) while comparing to global reanalyses (Interim ECMWF Reanalysis (ERA-Interim), Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2)) and observation-based datasets (Global Precipitation Climatology Centre (GPCC), Global Land Evaporation Amsterdam Model (GLEAM)). All 26 major European river basins are included in this study and aggregated to 17 catchments. Discharge data are obtained from the Global Runoff Data Centre (GRDC), and insufficiently long time series are extended by calibrating the monthly Génie Rural rainfall-runoff model (GR2M) against the existing discharge observations, subsequently generating consistent model discharge time series for the GRACE period. We find that for most catchments, COSMO-REA6 closes the water budget within the error estimates. In contrast, the global reanalyses underestimate PE with up to 20 mm/month. For all models and catchments, short-term (below the seasonal timescale) variability of atmospheric terrestrial flux agrees well with GRACE and discharge data with correlations of about 0.6. Our large study area allows identifying regional patterns like negative trends of PE in eastern Europe and positive trends in northwestern Europe. Full article
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Open AccessArticle
Hydropower Royalties: A Comparative Analysis of Major Producing Countries (China, Brazil, Canada and the United States)
Water 2017, 9(4), 287; doi:10.3390/w9040287 -
Abstract
Hydropower is the leading renewable source of electricity generation and a low emission energy source. In order to be developed sustainably, it is important that its costs and benefits are adequately set and distributed. Different mechanisms, such as royalties, can be used for
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Hydropower is the leading renewable source of electricity generation and a low emission energy source. In order to be developed sustainably, it is important that its costs and benefits are adequately set and distributed. Different mechanisms, such as royalties, can be used for this purpose. Governments have usually kept hydropower royalty rates low, without internalizing negative externalities. This strategy is inefficient because it leads to larger electricity production and consumption, and hence exacerbates environmental impacts. This paper reviews the criteria proposed and used to set hydropower royalties. It also compares practices of the four main hydropower producers in the world: China, Brazil, Canada and the United States. Results show that royalty rates and distribution policies are determined in an arbitrary and unsystematic manner, but also that water use is usually undervalued. In order to encourage the development of this key renewable resource, in a sustainable and responsible way, national and international efforts should be made to rationalize and harmonize hydropower royalty rates. Full article
Open AccessReview
Urban Water Cycle Simulation/Management Models: A Review
Water 2017, 9(4), 285; doi:10.3390/w9040285 -
Abstract
Urban water management is increasingly important given the need to maintain water resources that comply with global and local standards of quantity and quality. The effective management of water resources requires the optimization of financial resources without forsaking social requirements. A number of
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Urban water management is increasingly important given the need to maintain water resources that comply with global and local standards of quantity and quality. The effective management of water resources requires the optimization of financial resources without forsaking social requirements. A number of mathematical models have been developed for this task; such models account for all components of the Urban Water Cycle (UWC) and their interactions. The wide range of models entails the need to understand their differences in an effort to identify their applicability, so academic, state, and private sectors can employ them for environmental, economic, and social ends. This article presents a description of the UWC and relevant components, a literature review of different models developed between 1990 and 2015, and an analysis of several case studies (applications). It was found that most applications are focused on new supply sources, mainly rainwater. In brief, this article provides an overview of each model’s use (primarily within academia) and potential use as a decision-making tool. Full article
Open AccessArticle
Temporal Distribution Characteristics of Alpine Precipitation and Their Vertical Differentiation: A Case Study from the Upper Shule River
Water 2017, 9(4), 284; doi:10.3390/w9040284 -
Abstract
Alpine precipitation is an important component of the mountain hydrological cycle and may also be a determinant of water resources in inland river basins. In this study, based on field observation data of the upper Shule River and daily precipitation records of the
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Alpine precipitation is an important component of the mountain hydrological cycle and may also be a determinant of water resources in inland river basins. In this study, based on field observation data of the upper Shule River and daily precipitation records of the Tuole weather station during 2009–2015, temporal distribution characteristics of alpine precipitation and their vertical differentiation were evaluated mainly using percentages of precipitation anomalies (Pa), coefficient of variation (Cv), precipitation concentration degree (PCD) and concentration period (PCP). The results indicated that the inter-annual variability of annual precipitation was generally small, with a Pa that was only somewhat larger in low altitude zones for individual years; the inter-annual fluctuation of monthly precipitation increased noticeably, but the Cv and precipitation can be described as a power function. Annual distribution was basically consistent; more than 85.6% of precipitation was concentrated during the period from May to September; PCD ranged between 0.71 and 0.83 while the PCP was located within the 37th–41st pentads. Diurnal variation of precipitation was defined, mainly occurring from 1500 to 0100 Local Standard Time, and displayed a vertical change that was dominated by precipitation intensity or precipitation frequency. The temporal distribution of alpine precipitation has a noticeable vertical differentiation, and this is likely to originate from the diversity of precipitation mechanisms in mountainous terrain areas. Full article
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Open AccessArticle
Can Water Abundance Compensate for Weak Water Governance? Determining and Comparing Dimensions of Irrigation Water Security in Tajikistan
Water 2017, 9(4), 286; doi:10.3390/w9040286 -
Abstract
In this paper we consider both hydrology and governance as critical dimensions for irrigation water security. We scale down the overall water security concept to the agricultural sector, suggest an index of irrigation water security faced by farmers, and provide an empirical illustration
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In this paper we consider both hydrology and governance as critical dimensions for irrigation water security. We scale down the overall water security concept to the agricultural sector, suggest an index of irrigation water security faced by farmers, and provide an empirical illustration in the case of Tajikistan. Irrigation water security is investigated by three different dimensions: (a) a hydrology dimension, expressing a lack of water availability; (b) a governance dimension, the perceived difficulty in accessing water; and (c) a hybrid dimension of governance and hydrology. We developed an irrigation water security index, which we empirically tested using farm household survey data (N = 399). This index provides evidence that different farm types, e.g., small versus large, perceive different water security threats. Further, we found that if one dimension is less distinctive, the complementary dimension occurs as a coping mechanism. Thus, we conclude that diversified support mechanisms for infrastructure and management are needed to reach a higher level of water security. Full article
Open AccessArticle
Daily Based Morgan–Morgan–Finney (DMMF) Model: A Spatially Distributed Conceptual Soil Erosion Model to Simulate Complex Soil Surface Configurations
Water 2017, 9(4), 278; doi:10.3390/w9040278 -
Abstract
In this paper, we present the Daily based Morgan–Morgan–Finney model. The main processes in this model are based on the Morgan–Morgan–Finney soil erosion model, and it is suitable for estimating surface runoff and sediment redistribution patterns in seasonal climate regions with complex surface
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In this paper, we present the Daily based Morgan–Morgan–Finney model. The main processes in this model are based on the Morgan–Morgan–Finney soil erosion model, and it is suitable for estimating surface runoff and sediment redistribution patterns in seasonal climate regions with complex surface configurations. We achieved temporal flexibility by utilizing daily time steps, which is suitable for regions with concentrated seasonal rainfall. We introduce the proportion of impervious surface cover as a parameter to reflect its impacts on soil erosion through blocking water infiltration and protecting the soil from detachment. Also, several equations and sequences of sub-processes are modified from the previous model to better represent physical processes. From the sensitivity analysis using the Sobol’ method, the DMMF model shows the rational response to the input parameters which is consistent with the result from the previous versions. To evaluate the model performance, we applied the model to two potato fields in South Korea that had complex surface configurations using plastic covered ridges at various temporal periods during the monsoon season. Our new model shows acceptable performance for runoff and the sediment loss estimation (NSE0.63, |PBIAS|17.00, and RSR0.57). Our findings demonstrate that the DMMF model is able to predict the surface runoff and sediment redistribution patterns for cropland with complex surface configurations. Full article
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Open AccessArticle
Large Differences between Glaciers 3D Surface Extents and 2D Planar Areas in Central Tianshan
Water 2017, 9(4), 282; doi:10.3390/w9040282 -
Abstract
Most glaciers in China lie in high mountainous environments and have relatively large surface slopes. Common analyses consider glaciers’ projected areas (2D Area) in a two-dimensional plane, which are much smaller than glacier’s topographic surface extents (3D Area). The areal difference between 2D
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Most glaciers in China lie in high mountainous environments and have relatively large surface slopes. Common analyses consider glaciers’ projected areas (2D Area) in a two-dimensional plane, which are much smaller than glacier’s topographic surface extents (3D Area). The areal difference between 2D planar areas and 3D surface extents exceeds −5% when the glacier’s surface slope is larger than 18°. In this study, we establish a 3D model in the Muzart Glacier catchment using ASTER GDEM data. This model is used to quantify the areal difference between glaciers’ 2D planar areas and their 3D surface extents in various slope zones and elevation bands by using the second Chinese Glacier Inventory (CGI2). Finally, we analyze the 2D and 3D area shrinking rate between 2007 and 2013 in Central Tianshan using glaciers derived from Landsat images by an object-based classification approach. This approach shows an accuracy of 89% when it validates by comparison of glaciers derived from Landsat and high spatial resolution GeoEye images. The extracted glaciers in 2007 also have an agreement of 89% with CGI2 data in the Muzart Glacier catchment. The glaciers’ 3D area is 34.2% larger than their 2D area from CGI2 in the Muzart Glacier catchment and by 27.9% in the entire Central Tianshan. Most underestimation occurs in the elevation bands of 4000–5000 m above sea level (a.s.l.). The 3D glacier areas reduced by 30 and 115 km2 between 2007 and 2013 in the Muzart Glacier catchment and Central Tianshan, being 37.0% and 27.6% larger than their 2D areas reduction, respectively. The shrinking rates decrease with elevation increase. Full article
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Open AccessArticle
Characterization of Dissolved Organic Matter in Deep Geothermal Water from Different Burial Depths Based on Three-Dimensional Fluorescence Spectra
Water 2017, 9(4), 266; doi:10.3390/w9040266 -
Abstract
Dissolved organic matter (DOM) plays an important role in the chemical evolution of groundwater. Thus, in order to understand the composition and characteristics of DOM in groundwater, analyzed 31geothermal water samples from five aquifers (i.e., between 600 m and 1600 m) in the
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Dissolved organic matter (DOM) plays an important role in the chemical evolution of groundwater. Thus, in order to understand the composition and characteristics of DOM in groundwater, analyzed 31geothermal water samples from five aquifers (i.e., between 600 m and 1600 m) in the city of Kaifeng were analyzed and the results were compared in order to clarify their spatial distribution, characteristics, sources, and environmental influences. Results show that as the depth of a thermal reservoir increases, the ultraviolet absorption (UV254) of geothermal water does not change significantly, the concentration of dissolved organic carbon (DOC) gradually increases with depth, and the fluorescence intensity of DOM remains weak. Some differences are also evident with regard to the location and intensity of geothermal water sample DOM fluorescence peaks depending on thermal reservoir. The results of this study show that the main source of DOM in geothermal water is endogenous, derived from high stability organic matter derived from sedimentary processes and associated microbial activity. Within the three geothermal reservoir depth ranges, 600 m to 800 m, 800 m to 1000 m, and 1000 m to 1200 m, DOM components were mainly protein-like as well as soluble microbial metabolites. However, at deeper depths, within the 1200 m to 1400 m and 1400 m to 1600 m thermal reservoirs, the proportion of protein-like components in DOM decreased, while the ratio fulvic-like and humic-like components increased, leading to changes in the positions of fluorescence peaks. Finally, our results demonstrate a close relationship between the intensity of fluorescence peaks, suggesting that a number of fluorescent components may share a common source. Full article
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