Water

955 KiB

Open AccessArticle

The Paradox of Water Management Projects in Central Asia: An Institutionalist Perspective

by Lioudmila Chatalova, Nodir Djanibekov, Taras Gagalyuk and Vladislav Valentinov

Water 2017, 9(4), 300; https://doi.org/10.3390/w9040300 - 24 Apr 2017

Cited by 20 | Viewed by 6858

After the disintegration of the Soviet Union, the Central Asian countries have been faced with numerous development challenges in agriculture, especially those related to water use. Well-intentioned foreign donors and development agencies have stepped in to support local farmers, research centers, and public [...] Read more.

After the disintegration of the Soviet Union, the Central Asian countries have been faced with numerous development challenges in agriculture, especially those related to water use. Well-intentioned foreign donors and development agencies have stepped in to support local farmers, research centers, and public authorities in devising innovative solutions. Yet, development aid projects have borne fruit only partially. Paradoxically, innovative and apparently useful technologies proposed by foreign donors have rarely and only partially succeeded in taking root in the local institutional contexts. To explain this paradox, this paper draws on the institutional approach which shows the possibility of technological innovations being encapsulated by dysfunctional institutions. Reviewing recent studies of water-related projects in Central Asia, the paper shows this encapsulation to be at the core of the development project failures pervasive both in the Soviet period and today. If the concept of encapsulation is valid, then the current development efforts can be made more effective by detecting and counteracting the structures of vested interest on the part of all the actors involved, such as foreign donors, public authorities, research centers and local farmers. Full article

(This article belongs to the Special Issue The Future of Water Management in Central Asia)

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2450 KiB

Open AccessArticle

Understanding and Control of Biopolymer Fouling in Ultrafiltration of Different Water Types

by Xing Zheng, Frederik Zietzschmann, Stephan Plume, Hendrik Paar, Mathias Ernst, Zi Wang and Martin Jekel

Water 2017, 9(4), 298; https://doi.org/10.3390/w9040298 - 23 Apr 2017

Cited by 18 | Viewed by 6047

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 [...] Read more.

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

(This article belongs to the Special Issue Assessment of Water Quality and Treatment Technologies in Potable Water Use)

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582 KiB

Open AccessArticle

Re-Staging La Rasgioni: Lessons Learned from Transforming a Traditional Form of Conflict Resolution to Engage Stakeholders in Agricultural Water Governance

by Maria Laura Ruiu, Sante Maurizi, Simone Sassu, Giovanna Seddaiu, Olga Zuin, Chris Blackmore and Pier Paolo Roggero

Water 2017, 9(4), 297; https://doi.org/10.3390/w9040297 - 22 Apr 2017

Cited by 9 | Viewed by 6235

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 [...] Read more.

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

(This article belongs to the Special Issue Water Governance in Times of Change: Perceptions, Institutions, Praxis and Learning)

3338 KiB

Open AccessArticle

Pluvial Flooding in European Cities—A Continental Approach to Urban Flood Modelling

by Selma B. Guerreiro, Vassilis Glenis, Richard J. Dawson and Chris Kilsby

Water 2017, 9(4), 296; https://doi.org/10.3390/w9040296 - 22 Apr 2017

Cited by 45 | Viewed by 10984

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 [...] Read more.

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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1315 KiB

Open AccessArticle

Performance and Yeast Tracking in A Full-Scale Oil-Containing Paromomycin Production Wastewater Treatment System Using Yeast

by Chunyan Wang, Ran Ding, Yingxin Gao, Min Yang and Yu Zhang

Water 2017, 9(4), 295; https://doi.org/10.3390/w9040295 - 22 Apr 2017

Cited by 4 | Viewed by 6372

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 [...] Read more.

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

(This article belongs to the Special Issue Oily Water Treatment)

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1154 KiB

Open AccessArticle

Numerical Simulation of Soil Evaporation with Sand Mulching and Inclusion

by Wenju Zhao, Ping Yu, Xiaoyi Ma, Jie Sheng and Changquan Zhou

Water 2017, 9(4), 294; https://doi.org/10.3390/w9040294 - 22 Apr 2017

Cited by 8 | Viewed by 5575

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, [...] Read more.

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

(This article belongs to the Special Issue Modeling of Water Systems)

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3779 KiB

Open AccessArticle

Adaptation of Cascade Hydropower Station Scheduling on A Headwater Stream of the Yangtze River under Changing Climate Conditions

by Ming Yang Zhai, Qian Guo Lin, Guo He Huang, Le Zhu, Kai An, Gong Chen Li and Yue Fei Huang

Water 2017, 9(4), 293; https://doi.org/10.3390/w9040293 - 22 Apr 2017

Cited by 12 | Viewed by 5704

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, [...] Read more.

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

(This article belongs to the Special Issue Adaptation Strategies to Climate Change Impacts on Water Resources)

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12919 KiB

Open AccessArticle

Comparison of IMERG Level-3 and TMPA 3B42V7 in Estimating Typhoon-Related Heavy Rain

by Ren Wang, Jianyao Chen and Xianwei Wang

Water 2017, 9(4), 276; https://doi.org/10.3390/w9040276 - 22 Apr 2017

Cited by 33 | Viewed by 5849

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 [...] Read more.

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

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

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5000 KiB

Open AccessArticle

Assessment of Social Vulnerability to Flood in Urban Côte d’Ivoire Using the MOVE Framework

by Malan Ketcha Armand Kablan, Kouassi Dongo and Mamadou Coulibaly

Water 2017, 9(4), 292; https://doi.org/10.3390/w9040292 - 21 Apr 2017

Cited by 67 | Viewed by 11277

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 [...] Read more.

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

(This article belongs to the Special Issue Innovative Aspects in Flood Risk Evaluation, Mapping and Communication)

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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

by Jae Yeol Song and Eun-Sung Chung

Water 2017, 9(4), 291; https://doi.org/10.3390/w9040291 - 21 Apr 2017

Cited by 41 | Viewed by 7913

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 [...] Read more.

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

Modeling Coupled Water and Heat Transport in the Root Zone of Winter Wheat under Non-Isothermal Conditions

by Rong Ren, Juanjuan Ma, Qiyun Cheng, Lijian Zheng, Xianghong Guo and Xihuan Sun

Water 2017, 9(4), 290; https://doi.org/10.3390/w9040290 - 21 Apr 2017

Cited by 6 | Viewed by 5095

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 [...] Read more.

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

(This article belongs to the Special Issue Modeling Subsurface Flow and Heat Transport at Variable Scales in Heterogeneous Media)

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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

by Eleonora Spada, Marco Sinagra, Tullio Tucciarelli and Daniela Biondi

Water 2017, 9(4), 288; https://doi.org/10.3390/w9040288 - 21 Apr 2017

Cited by 7 | Viewed by 6206

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 [...] Read more.

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

by Ireneusz Laks, Mariusz Sojka, Zbigniew Walczak and Rafał Wróżyński

Water 2017, 9(4), 283; https://doi.org/10.3390/w9040283 - 21 Apr 2017

Cited by 30 | Viewed by 5894

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 [...] Read more.

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

(This article belongs to the Special Issue Modeling of Water Systems)

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Open AccessFeature PaperArticle

Evaluation of the Water Cycle in the European COSMO-REA6 Reanalysis Using GRACE

by Anne Springer, Annette Eicker, Anika Bettge, Jürgen Kusche and Andreas Hense

Water 2017, 9(4), 289; https://doi.org/10.3390/w9040289 - 20 Apr 2017

Cited by 15 | Viewed by 8904

Abstract

Precipitation and evapotranspiration, and in particular the precipitation minus evapotranspiration deficit (

P - E

), are climate variables that may be better represented in reanalyses based on numerical weather prediction (NWP) models than in other datasets.

P - E

provides essential information [...] Read more.

Precipitation and evapotranspiration, and in particular the precipitation minus evapotranspiration deficit (

P - E

), are climate variables that may be better represented in reanalyses based on numerical weather prediction (NWP) models than in other datasets.

P - E

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

P - E

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

P - E

in eastern Europe and positive trends in northwestern Europe. Full article

(This article belongs to the Special Issue The Use of Remote Sensing in Hydrology)

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Open AccessArticle

Hydropower Royalties: A Comparative Analysis of Major Producing Countries (China, Brazil, Canada and the United States)

by Pierre-Olivier Pineau, Lucile Tranchecoste and Yenny Vega-Cárdenas

Water 2017, 9(4), 287; https://doi.org/10.3390/w9040287 - 20 Apr 2017

Cited by 15 | Viewed by 10755

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 [...] Read more.

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

(This article belongs to the Special Issue Water Economics and Policy)

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Open AccessArticle

Can Water Abundance Compensate for Weak Water Governance? Determining and Comparing Dimensions of Irrigation Water Security in Tajikistan

by Frederike Klümper, Thomas Herzfeld and Insa Theesfeld

Water 2017, 9(4), 286; https://doi.org/10.3390/w9040286 - 19 Apr 2017

Cited by 16 | Viewed by 7211

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 [...] Read more.

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

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Open AccessReview

Urban Water Cycle Simulation/Management Models: A Review

by Carlos Andrés Peña-Guzmán, Joaquín Melgarejo, Daniel Prats, Andrés Torres and Sandra Martínez

Water 2017, 9(4), 285; https://doi.org/10.3390/w9040285 - 19 Apr 2017

Cited by 30 | Viewed by 15655

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 [...] Read more.

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

(This article belongs to the Special Issue Synergies in Urban Water Infrastructure Modeling)

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Open AccessArticle

Temporal Distribution Characteristics of Alpine Precipitation and Their Vertical Differentiation: A Case Study from the Upper Shule River

by Qingfeng Li and Guojing Yang

Water 2017, 9(4), 284; https://doi.org/10.3390/w9040284 - 19 Apr 2017

Cited by 9 | Viewed by 5313

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 [...] Read more.

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

(This article belongs to the Special Issue Sustainable Water Management within Inland River Watershed)

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7333 KiB

Open AccessArticle

Large Differences between Glaciers 3D Surface Extents and 2D Planar Areas in Central Tianshan

by Xianwei Wang, Huijiao Chen and Yaning Chen

Water 2017, 9(4), 282; https://doi.org/10.3390/w9040282 - 17 Apr 2017

Cited by 5 | Viewed by 6124

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 [...] Read more.

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

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

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175 KiB

Open AccessEditorial

Water Resources Management: Innovation and Challenges in a Changing World

by Ashantha Goonetilleke and Meththika Vithanage

Water 2017, 9(4), 281; https://doi.org/10.3390/w9040281 - 17 Apr 2017

Cited by 34 | Viewed by 10306

Abstract

The prudent management of water resources is essential for human and ecosystem well-being. As a result of ever escalating and competing demands, compounded by pollution and climate change-driven impacts, available freshwater resources are becoming increasingly stressed. This is further compounded by poor management [...] Read more.

The prudent management of water resources is essential for human and ecosystem well-being. As a result of ever escalating and competing demands, compounded by pollution and climate change-driven impacts, available freshwater resources are becoming increasingly stressed. This is further compounded by poor management practices and the unsustainable extraction of water. Consequently, many parts of the world, particularly urban areas, are facing water shortages. Therefore, water resources management requires a clear understanding of the ongoing challenges and innovative approaches. This Special Issue provides the platform for the dissemination of knowledge and best practices to strengthen the management of our precious water resources into the future. Full article

(This article belongs to the Special Issue Water Resources Management: Innovation and Challenges in a Changing World)

7219 KiB

Open AccessArticle

Optimal Operation Research of Flood Retarding in Plain River Network Region

by Zhenye Zhu, Zengchuan Dong, Wanhong Yang, Jie Zhou, Dayong Li, Xiaohua Fu and Wei Xu

Water 2017, 9(4), 280; https://doi.org/10.3390/w9040280 - 17 Apr 2017

Cited by 6 | Viewed by 5189

Abstract

The operation of flood retarding areas does not attract much attention, although they are important components of flood control systems. Poor operation of such areas restricts not only the socio-economic development of the flood retarding area, but also limits scientific flood control options. [...] Read more.

The operation of flood retarding areas does not attract much attention, although they are important components of flood control systems. Poor operation of such areas restricts not only the socio-economic development of the flood retarding area, but also limits scientific flood control options. As the second-largest flood retarding area in China, with more than 2000 km² and 300 polders, the Hongze Lake vicinity was taken as a case study of graded flood retarding. A one and two-dimensional coupled hydrodynamic model was established to simulate flood routing in the Hongze Lake area. Fifteen different schemes involving different flood magnitudes and flood retarding operations were simulated. The results show that (1) having a flood retarding area is essential; and (2) the “graded flood retarding” scheme is superior to “no grading flood retarding” scheme; and (3) a “two-grade flood retarding” scheme is recommended. Full article

(This article belongs to the Special Issue Innovative Aspects in Flood Risk Evaluation, Mapping and Communication)

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338 KiB

Open AccessArticle

Daily Based Morgan–Morgan–Finney (DMMF) Model: A Spatially Distributed Conceptual Soil Erosion Model to Simulate Complex Soil Surface Configurations

by Kwanghun Choi, Sebastian Arnhold, Bernd Huwe and Björn Reineking

Water 2017, 9(4), 278; https://doi.org/10.3390/w9040278 - 17 Apr 2017

Cited by 16 | Viewed by 11866

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 [...] Read more.

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 (

NSE \geq 0.63

,

| PBIAS | \leq 17.00

, and

RSR \leq 0.57

). 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

(This article belongs to the Special Issue Soil Erosion by Water)

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2699 KiB

Open AccessArticle

Characterization of Dissolved Organic Matter in Deep Geothermal Water from Different Burial Depths Based on Three-Dimensional Fluorescence Spectra

by Weifang Qiao, Xinyi Wang, Xiaoman Liu, Xiaoge Zhen, Jianwei Guo, Shidong Wang, Fang Yang, Guosheng Chen and Bo Zhang

Water 2017, 9(4), 266; https://doi.org/10.3390/w9040266 - 17 Apr 2017

Cited by 5 | Viewed by 6114

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 [...] Read more.

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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2977 KiB

Open AccessArticle

Effects of Local Weather Variation on Water-Column Stratification and Hypoxia in the Western, Sandusky, and Central Basins of Lake Erie

by Melanie M. Perello, Douglas D. Kane, Phoenix Golnick, Maya C. Hughes, Matt A. Thomas and Joseph D. Conroy

Water 2017, 9(4), 279; https://doi.org/10.3390/w9040279 - 16 Apr 2017

Cited by 15 | Viewed by 6504

Abstract

Hypoxia, low dissolved oxygen (DO) concentrations (<2 mg/L), has been a major issue in Lake Erie for decades. While much emphasis has been placed on biological factors, particularly algal blooms, contributing to hypolimnetic oxygen depletion, there has been little focus on the role [...] Read more.

Hypoxia, low dissolved oxygen (DO) concentrations (<2 mg/L), has been a major issue in Lake Erie for decades. While much emphasis has been placed on biological factors, particularly algal blooms, contributing to hypolimnetic oxygen depletion, there has been little focus on the role of weather. For this study, we monitored water temperature and DO concentrations at sites in the western, central, and Sandusky basins in Lake Erie during June and July 2010–2012. We then compared trends in stratification and DO concentrations to weather patterns during that period. We found that during those three years, there was significant variation in weather patterns, particularly decreased ice coverage and increased storm events in 2012. These weather patterns corresponded to 2012 having the warmest water temperatures, some of the lowest DO concentrations, and a deeper and thinner hypolimnion (especially in the central basin) than the previous years. We found a relationship between weather and hypoxia, providing further evidence for why these basins are susceptible to low DO conditions during summer months. The role of weather in hypoxia is another indication that the lake is vulnerable to effects of climate change and should be considered in management strategies. Full article

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10786 KiB

Open AccessArticle

Development of an Integrated Water Quality and Macroalgae Simulation Model for Tidal Marsh Eutrophication Control Decision Support

by Yan Chen, Rui Zou, Su Han, Sen Bai, Mustafa Faizullabhoy, Yueying Wu and Huaicheng Guo

Water 2017, 9(4), 277; https://doi.org/10.3390/w9040277 - 15 Apr 2017

Cited by 10 | Viewed by 5056

Abstract

Numerical modeling is an efficient and useful method for understanding the hydrodynamics and water quality responses to nutrient loading changes and other management in estuarine and coastal systems. In this study, the Environmental Fluid Dynamic Code (EFDC) was applied in the Famosa Slough, [...] Read more.

Numerical modeling is an efficient and useful method for understanding the hydrodynamics and water quality responses to nutrient loading changes and other management in estuarine and coastal systems. In this study, the Environmental Fluid Dynamic Code (EFDC) was applied in the Famosa Slough, a small tidal marsh system in urban San Diego County, California, to analyze multiple management scenarios focusing on different aspects of controlling processes: watershed load reduction, macroalgae harvesting, dredging, and the combination of different options. In order to evaluate these management scenarios, a previous EFDC model was enhanced through modifying the model code to allow simulations of both benthic and floating macroalgae as separate state variables, and configuring a sediment diagenesis model to predictively represent the dynamic interactions between the watershed load and benthic nutrient flux. The model was calibrated and verified by comparing model predictions with the observed data of hydrodynamic and water quality parameters throughout 2008. The calibrated model was then applied to simulate the water quality response to various management scenarios. The simulated results showed that combining watershed nutrient load reductions and harvesting floating macroalgae can produce significant water quality benefits. The results provide useful information for hydrological ecosystem protection and can be used for determining cost-effective implementation actions in the future. Full article

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2972 KiB

Open AccessArticle

Dynamic Assessment of Comprehensive Water Quality Considering the Release of Sediment Pollution

by Tianxiang Wang, Shiguo Xu and Jianwei Liu

Water 2017, 9(4), 275; https://doi.org/10.3390/w9040275 - 15 Apr 2017

Cited by 15 | Viewed by 5460

Abstract

Comprehensive assessment of water quality is an important technological measure for water environmental management and protection. Previous assessment methods tend to ignore the influences of sediment pollutant release and dynamic change of the water boundary. In view of this, this paper explores a [...] Read more.

Comprehensive assessment of water quality is an important technological measure for water environmental management and protection. Previous assessment methods tend to ignore the influences of sediment pollutant release and dynamic change of the water boundary. In view of this, this paper explores a new method for comprehensive water quality assessment. Laboratory simulation experiments are conducted to analyze the influences of sediment pollutant release on water quality, and the results are taken as increments, coupled with original samples, to constitute a new set of evaluation samples. Dynamic and comprehensive water quality assessment methods are created based on a principal component analysis (PCA)/analytic hierarchy process (AHP)–variable fuzzy pattern recognition (VFPR) model and adopted to evaluate water quality. A geographic information system (GIS) is applied to visually display the results of water quality assessment and the change of the water boundary. This study takes Biliuhe Reservoir as an engineering example. The results show the change process of the water boundary, during which the water level is reduced from 63.10 m to 54.15 m. The reservoir water quality is fine, of which the water quality level (GB3838-2002) is between level 2 and level 3, and closer to level 2 taking no account of sediment pollutant release. The water quality of Biliuhe Reservoir, overall, is worse in summer and better in winter during the monitoring period. Meanwhile, the water quality shows the tendency of being better from upstream to downstream, and the water quality in the surface layer is better than that in the bottom layer. However, water quality is much closer, or even inferior, to level 3 when considering the release of nitrogen and phosphorus in sediments, and up to 42.7% of the original assessment results of the samples undergo changes. It is concluded that the proposed method is comparatively reasonable as it avoids neglecting sediment pollutant release in the water quality assessment, and the presentation of the evaluation results and change of the water boundary is intuitive with the application of GIS. Full article

(This article belongs to the Special Issue Water Quality and Health)

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3539 KiB

Open AccessArticle

Experimental Investigation on Air-Water Interaction in a Hydropower Station Combining a Diversion Tunnel with a Tailrace Tunnel

by Wen Zhang, Fulin Cai, Jianxu Zhou and Yulong Hua

Water 2017, 9(4), 274; https://doi.org/10.3390/w9040274 - 13 Apr 2017

Cited by 12 | Viewed by 4760

Abstract

Diversion tunnels are often used as tailrace tunnels in underground hydropower stations. The special layout results in complex flow regimes, including air-water two-phase flow. A set of experiments is conducted based on the model of a hydropower station which combines partial diversion tunnels [...] Read more.

Diversion tunnels are often used as tailrace tunnels in underground hydropower stations. The special layout results in complex flow regimes, including air-water two-phase flow. A set of experiments is conducted based on the model of a hydropower station which combines partial diversion tunnels with tailrace tunnels to investigate the interactions between the air and water phases in the combined diversion tunnels. Interactions between the air and water phases observed in the combined diversion tunnel significantly alter flow dynamics, and are classified into four types according to the initial tail water level. There is a range of initial tail water levels in which the interaction between the air and water phases cannot be neglected, and the range becomes greater when the change in flow rate increases. Such interactions may cause a pressure surge and the pressure surge reaches the maximum when the initial tail water level is approximately equal to the crown of the tunnel. The surge pressures do harm to the safety and stability of hydropower stations, so the condition should be considered and controlled. Full article

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13921 KiB

Open AccessArticle

The Impact of Integrated Aquifer Storage and Recovery and Brackish Water Reverse Osmosis (ASRRO) on a Coastal Groundwater System

by Steven Eugenius Marijnus Ros and Koen Gerardus Zuurbier

Water 2017, 9(4), 273; https://doi.org/10.3390/w9040273 - 12 Apr 2017

Cited by 9 | Viewed by 9905

Abstract

Aquifer storage and recovery (ASR) of local, freshwater surpluses is a potential solution for freshwater supply in coastal areas, as is brackish water reverse osmosis (BWRO) of relatively shallow groundwater in combination with deeper membrane concentrate disposal. A more sustainable and reliable freshwater [...] Read more.

Aquifer storage and recovery (ASR) of local, freshwater surpluses is a potential solution for freshwater supply in coastal areas, as is brackish water reverse osmosis (BWRO) of relatively shallow groundwater in combination with deeper membrane concentrate disposal. A more sustainable and reliable freshwater supply may be achieved by combining both techniques in one ASRRO system using multiple partially penetrating wells (MPPW). The impact of widespread use of ASRRO on a coastal groundwater system was limited based on regional groundwater modelling but it was shown that ASRRO decreased the average chloride concentration with respect to the autonomous scenario and the use of BWRO. ASRRO was successful in mitigating the local negative impact (saltwater plume formation) caused by the deep disposal of membrane concentrate during BWRO. The positive impacts of ASRRO with respect to BWRO were observed in the aquifer targeted for ASR and brackish water abstraction (Aquifer 1), but foremost in the deeper aquifer targeted for membrane concentrate disposal (Aquifer 2). The formation of a horizontal freshwater barrier was found at the top of both aquifers, reducing saline seepage. The disposal of relatively fresh concentrate in Aquifer 2 led to brackish water outflow towards the sea. The net abstraction in Aquifer 1 enforced saltwater intrusion, especially when BWRO was applied. The conclusion of this study is that ASRRO can provide a sustainable alternative for BWRO. Full article

(This article belongs to the Special Issue Water Quality Considerations for Managed Aquifer Recharge Systems)

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4260 KiB

Open AccessArticle

Comparative Analysis of HRU and Grid-Based SWAT Models

by Garett Pignotti, Hendrik Rathjens, Raj Cibin, Indrajeet Chaubey and Melba Crawford

Water 2017, 9(4), 272; https://doi.org/10.3390/w9040272 - 12 Apr 2017

Cited by 48 | Viewed by 14198

Abstract

A grid-based version of the Soil and Water Assessment Tool (SWAT) model, SWATgrid, was developed to perform simulations on a regularized grid with a modified routing algorithm to allow interaction between grid cells. However, SWATgrid remains largely untested with little understanding of the [...] Read more.

A grid-based version of the Soil and Water Assessment Tool (SWAT) model, SWATgrid, was developed to perform simulations on a regularized grid with a modified routing algorithm to allow interaction between grid cells. However, SWATgrid remains largely untested with little understanding of the impact of user-defined grid cell size. Moreover, increases in computation time effectively preclude direct calibration of SWATgrid. To gain insight into defining appropriate strategies for future development and application of SWATgrid, this research considers the simulated differences between commonly-employed hydrologic response unit (HRU)-based and grid-based SWAT models and the implications of resolution on their simulation and calibrated parameter values for a Midwestern, agricultural watershed. Results indicate that: (1) the gridded approach underpredicted simulated streamflow between 5% and 50% relative to the baseline model, depending upon the input spatial resolution and routing algorithm implemented; (2) gridded models generally underpredicted total phosphorous and sediment loads while overpredicting nitrate load; and (3) ranges of values of optimized model parameters remained similar up to 90 m. Results from this analysis should help in defining future applications of the SWATgrid model and the effects of differing spatial resolution of the model input data. Full article

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2420 KiB

Open AccessFeature PaperArticle

Full Spectrum Analytical Channel Design with the Capacity/Supply Ratio (CSR)

by Travis R. Stroth, Brian P. Bledsoe and Peter A. Nelson

Water 2017, 9(4), 271; https://doi.org/10.3390/w9040271 - 12 Apr 2017

Cited by 6 | Viewed by 5897

Abstract

Analytical channel design tools have not advanced appreciably in the last decades, and continue to produce designs based upon a single representative discharge that may not lead to overall sediment continuity. It is beneficial for designers to know when a simplified design may [...] Read more.

Analytical channel design tools have not advanced appreciably in the last decades, and continue to produce designs based upon a single representative discharge that may not lead to overall sediment continuity. It is beneficial for designers to know when a simplified design may be problematic and to efficiently produce alternative designs that approximate sediment balance over the entire flow regime. The Capacity/Supply Ratio (CSR) approach—an extension of the Copeland method of analytical channel design for sand channels—balances the sediment transport capacity of a design reach with the sediment supply of a stable upstream reach over the entire flow duration curve (FDC) rather than just a single discharge. Although CSR has a stronger physical basis than previous analytical channel design approaches, it has not been adopted in practice because it can be a cumbersome and time-consuming iterative analysis without the use of software. We investigate eighteen sand-bed rivers in a comparison of designs based on the CSR approach and five single-discharge metrics: the effective discharge (Q_eff) or discharge that transports the most sediment over time; the 1.5-year recurrence interval discharge (Q_1.5); the bankfull discharge (Q_bf); and the discharges associated with 50th (Q_s₅₀) and 75th (Q_s₇₅) percentiles of the cumulative sediment yield curve. To facilitate this analysis, we developed a novel design tool using the Visual Basic for Applications (VBA) programming language in Excel^® to produce stable channel slope/width combinations based on the CSR methodology for both sand- and gravel-bed streams. The CSR Stable Channel Design Tool’s (CSR Tool) code structure was based on Copeland’s method in SAM and HEC-RAS (Hydrologic Engineering Center’s River Analysis System) and was tested with a single discharge to verify outputs. The Q_s₅₀ and Q_s₇₅ single-discharge designs match the CSR output most closely, followed by the Q_bf, Q_eff, and Q_1.5. The Q_eff proved to be the most inconsistent design metric because it can be highly dependent on the binning procedure used in the effectiveness analysis. Furthermore, we found that the more rigorous physical basis of the CSR analysis is potentially most important in designing “labile” channels with highly erodible substrate, high perennial flow “flashiness”, low width-to-depth ratio, and high incoming sediment load. The CSR Tool provides a resource for river restoration practitioners to efficiently utilize design techniques that can promote sediment balance in dynamic fluvial systems. Full article

(This article belongs to the Special Issue Stream Channel Stability, Assessment, Modeling, and Mitigation)

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