Water Resource Management Issues Research Articles

Modelling of Nutrient Pollution Dynamics in River Basins: A Review with a Perspective of a Distributed Modelling Approach

Nutrient pollution is one of the major issues in water resources management, which has drawn significant investments into the development of many modelling tools to solve pollution problems worldwide. However, the situation remains unchanged, even likely to be exacerbated due to population growth and climate change. Effective measures to alleviate the issues are essential, dependent upon existing modelling tools’ capacities. More complex models have been developed with technological advancement, though applications are mainly limited to academic reach. Hence, there is a need for a paradigm shift in policymaking that looks for a reliable modelling approach. This paper aims to assess the capacity of existing modelling tools in the context of process-based modelling and provide a future direction in research. The article has categorically divided models into plot scale to basin-wide applications for evaluation and discussed the pros and cons of conceptual and process-based modelling. The potential benefits of distributed modelling approach have been elaborated with highlights of a newly developed distributed model and its application in catchments in Japan and Australia. The distributed model is more adequate for predicting the realistic details of pollution problems in a changing environment. Future research needs to focus on more process-based modelling.

Spatio-temporal controls of C–N–P dynamics across headwater catchments of a temperate agricultural region from public data analysis

Abstract. Characterizing and understanding spatial variability in water quality for a variety of chemical elements is an issue for present and future water resource management. However, most studies of spatial variability in water quality focus on a single element and rarely consider headwater catchments. Moreover, they assess few catchments and focus on annual means without considering seasonal variations. To overcome these limitations, we studied spatial variability and seasonal variation in dissolved C, N, and P concentrations at the scale of an intensively farmed region of France (Brittany). We analysed 185 headwater catchments (from 5–179 km2) for which 10-year time series of monthly concentrations and daily stream flow were available from public databases. We calculated interannual loads, concentration percentiles, and seasonal metrics for each element to assess their spatial patterns and correlations. We then performed rank correlation analyses between water quality, human pressures, and soil and climate features. Results show that nitrate (NO3) concentrations increased with increasing agricultural pressures and base flow contribution; dissolved organic carbon (DOC) concentrations decreased with increasing rainfall, base flow contribution, and topography; and soluble reactive phosphorus (SRP) concentrations showed weaker positive correlations with diffuse and point sources, rainfall and topography. An opposite pattern was found between DOC and NO3: spatially, between their median concentrations, and temporally, according to their seasonal cycles. In addition, the quality of annual maximum NO3 concentration was in phase with maximum flow when the base flow index was low, but this synchrony disappeared when flow flashiness was lower. These DOC–NO3 seasonal cycle types were related to the mixing of flow paths combined with the spatial variability of their respective sources and to local biogeochemical processes. The annual maximum SRP concentration occurred during the low-flow period in nearly all catchments. This likely resulted from the dominance of P point sources. The approach shows that despite the relatively low frequency of public water quality data, such databases can provide consistent pictures of the spatio-temporal variability of water quality and of its drivers as soon as they contain a large number of catchments to compare and a sufficient length of concentration time series.

Modeling reference evapotranspiration using a novel regression-based method: radial basis M5 model tree

In the current study, an ability of a novel regression-based method is evaluated in modeling daily reference evapotranspiration (ET0), which is an important issue in water resources management and planning. The method was developed by hybridizing radial basis function and M5 model tree and called as radial basis M5 model tree (RM5Tree). The new model results were compared with traditional M5 model tree (M5Tree), response surface method (RSM), and two neural networks (multi-layer perceptron neural networks, MLPNN & radial basis function neural network, RBFNN) with respect to several statistical indices. Daily climatic data (relative humidity, RH, solar radiation, SR, wind speed, air temperature, T) recorded at three stations in Turkey, Mediterranean Region, were used. The effect of each weather data on ET0 was also investigated by utilizing three different input scenarios with various combinations of input variables. On the whole, the RM5Tree provided the best results (Nash and Sutcliffe efficiency, NES > 0.997) followed by the MLPNN (NES > 0.990), and M5Tree (NES > 0.945) in modeling daily ET0. The SR was observed as the most effective input parameter on ET0 which was followed by the T and RH. However, the findings of the third modeling scenario revealed that taking into account of all variables would considerably increase models’ accuracies for the three stations.

Social learning diffusion and influential stakeholders identification in socio-hydrological environments

In this paper, six critical topics in social learning (SL) definition and applications are discussed: 1- Clarification of the SL definition; 2- The role of SL in the management of shared water resources; 3- The definition of “learning” in SL; 4- The quantification of SL; 5- The relation of SL with outputs of Social Networks Analysis (SNA) and stakeholder Analysis (SA); 6- Identifying and ranking of key stakeholders (i.e., influencers) for SL diffusion. After defining SL, we present SL's role using a well-known game theory problem. We have addressed the term “learning” in SL using an existing method, namely reinforcement learning. We present a new approach for quantifying SL within a hydrological environment and finding key stakeholders for the SL diffusion. For the first time, we consider a combination of SL, SA, and SNA to propose a comprehensive social-based approach to investigate SL diffusion. The western part of Tehran city, which is suffering from some water and environmental issues such as overexploitation of groundwater and land subsidence, is the case study of this paper. The results show a significant relationship between SL and the outputs of SNA. The suggested method for identifying key stakeholders has been able to identify key stakeholders in terms of various water resources management issues in the study area. The results can be used for developing effective policies towards sustainable management of water and environmental resources in the studied socio-hydrological system.

Ethiopia Water Resources Quantitative Potentials, Management Issues and Challenges. A literature Review Article Paper

Ethiopia Water Resources Quantitative Potentials, Management Issues and Challenges. A literature Review Article Paper

River Flow Alterations Caused by Intense Anthropogenic Uses and Future Climate Variability Implications in the Balkans

River flow alterations, caused by climate variability/change and intense anthropogenic uses (e.g., flow regulation by dams) are considered among the main global challenges of which hydrologists should be dealing with. For the purpose of this study, environmental flow and potential hydrological alterations are made for the extended Drin river basin, with limited historical hydrological information available. To overcome this limitation environmental flow assessment is made using simulated streamflow data from a watershed hydrological model. Descriptive statistics applied to streamflow values indicate that median monthly flows with no anthropogenic uses are consistently greater than those with anthropogenic uses by 0–37.4 m3/s in all subbasins. Moreover, an investigation of potential climate variability/change impact on river flow regime is made using streamflow simulations from a global hydrological model. Results indicate that hydrologic alteration is intense between nonregulated and regulated streamflow conditions. More specifically, for all Global Circulation Models and Regional Climate Models combinations, and both regulated and unregulated streamflow conditions, the minimum discharge values had statistically significant decreasing trends, except one combination (RCP 4.5–RCA4/ECEARTH) for unregulated conditions. Finally, results from this preliminary analysis could enhance the necessary conversations among all relevant stakeholders to discuss and decide on sustainable water resources management issues for the development of a Drin Basin Management Plan in the future.

A Harmony-Based Approach for Assessing and Regulating Human-Water Relationships: A Case Study of Henan Province in China

The conflict of the human-water relationships (HWR) has further increased the water-related risks, such as water environment deterioration, water shortages, and even regional violent conflicts for obtaining usable water resources. Knowing how to evaluate and regulate the discordant HWR to form a balanced growth between sustainable socio-economy and water resources protection has become a critical issue in water resources management. The harmony theory method, which provides a new perspective for solving the conflict between humans and water, has been widely used in current studies. However, this method focuses less on the quantitative study of the balance status of HWR. This study proposes a harmony theory-based HWR evaluation method that contains a systematic process of harmony assessment, indicator identification, harmony balance constraints, and harmony regulation for assessing and regulating the discordant HWR. The Henan Province of China, which has a complicated HWR, was selected as a case study to apply and verify the approach proposed in this study. The results indicated that (1) Henan Province showed a poor harmony status. The human–water harmony degree of 18 distinctions in the province varied from 0.41 to 0.76, showing an increasing trend from 2006 to 2018, indicating that the HWR was gradually improving in recent years. (2) The human–water harmony degree showed that HWR in the southwest part of Henan Province, with less human activities, was better than that in its northeast part, which had faster social development. Sanmenxia City, located in the west part of the province, had the highest human–water harmony degree because of the recent water control projects implemented in the city, indicating that human production measures could effectively help improve HWR. (3) At present, Henan Province has serious discordant indicators in these three aspects (water system health, humanistic system development, and human-water system coordination), which proves that it is still facing pressure from both socio-economy sustainable development and water resources protection. Our results provide insight into water resources management in Henan Province and other similar regions.

Healthy waterways and ecologically sustainable cities in Beijing‐Tianjin‐Hebei urban agglomeration (northern China): Challenges and future directions

AbstractThe cities across the northern dry region of China are exposed to multiple sustainability challenges. Beijing‐Hebei‐Tianjin (BTH) urban agglomeration, for example, experiences severe water shortages due to rapidly expanding urban populations, industrial use, and irrigation‐intensive agriculture. Climate change has further threatened water resources security. Overuse of water resources to meet the demand of various water sectors has far‐reaching health and environmental implications including ecosystem sustainability. Surface water and groundwater pollution present public health risks. Despite the extraordinary policies and efforts being made and implemented by the Government of China, the BTH region currently lacks coordination among stakeholders leading to poor water governance. Consultation among scientists, engineers and stakeholders on regional water security issues is crucial and must be frequent and inclusive. An international symposium was held in Shijiazhuang in early November 2019 to identify some of the key water security challenges and scope of an idealized future eco‐city in the region by developing a sustainability framework. This work drew on experiences from across China and beyond. Scientists agree that integration of science, technology, and governance within an appropriate policy framework was particularly significant for combating the issue of water insecurity, including in the region's newly developed city, Xiong'an New Area. An emerging concept, “Healthy Waterways and Ecologically Sustainable Cities” which integrates social, ecological and hydrological systems and acts as an important pathway for sustainability in the 21st century was proposed in the symposium to tackle the problems in the region. This high level biophysical and cultural concept empowers development goals and promotes human health and wellbeing. The framework on healthy waterways and ecologically sustainable cities can overcome sustainability challenges by resolving water resource management issues in BTH in a holistic way. To implement the concept, we strongly recommend the utilization of evidence‐based scientific research and institutional cooperation including national and international collaborations to achieve the Healthy Waterways and Ecologically Sustainable Cities goal in the BTH in future.This article is categorized under: Water and Life > Conservation, Management, and Awareness

Aproximación a la gobernanza de las cuencas transfronterizas del Líbano y su geopolítica

El objetivo del presente artículo es analizar las cuencas transfronterizas entre la República del Líbano y los países ribereños, considerando aspectos de cooperación y conflicto, geopolíticos de la región árabe, así como gobernanza. Esto se complementa con la propuesta del paradigma de la Gestión Integrada de Recursos Hídricos (GIRH). Tradicionalmente, la cuestión de recursos hídricos compartidos en la región árabe ha estado altamente politizada, así como las negociaciones de alto nivel entre gobiernos han sido críticas. Al mismo tiempo, esto genera preocupación sobre la justicia y la seguridad hídrica. La atención ha estado centrada en disputas de largo recorrido surgidas de la dependencia árabe en recursos hídricos superficiales originados (o controlados por) países no árabes. El agua es uno de los recursos más preciados en Líbano, como en todo el mundo, en especial si se consideran los actuales y futuros escenarios de cambio climático. La crisis humanitaria de 1,5 millones de refugiados sirios en territorio libanés presiona en mayor medidasobre los servicios de agua y sobre los recursos; si bien dicha crisis hídrica antecede a la llegada de dichos refugiados y está marcada por la propia situación geopolítica. El agua disponible discurre por ríos, lagos, embalses y aguas subterráneas. Los recursos hídricos de este país se encuentran bajo estrés debido a distintos factores: prácticas de manejo no sostenibles, aumento de la demanda desde todos los sectores, contaminación y gobernanza inefectiva (casi ausente) del agua. El Líbano comparte las siguientes cuencas con países ribereños: el río Jordán, el río Orontes y el río Nahr Al Kabir. En lo que respecta a agua subterránea, la cadena montañosa de Anti-Líbano está ubicada en la frontera con Siria. La promoción de la cooperación es crucial para el manejo de los recursos hídricos compartidos en esta región. En este sentido, una acción más cooperativa y un diálogo constructivo son necesarios para gestionar estos recursos compartidos, considerando la gobernanza del agua, los principios de la hidrodiplomacia y la GIRH. Las preguntas que guían este estudio son conocer qué cuencas hídricas comparte el Líbano, cuáles son las características de las mismas, y si existen acuerdos internacionales que regulen su uso y aprovechamiento conjunto. En cuanto a la metodología utilizada, la siguiente investigación se basa en información de fuentes primarias y secundarias (investigaciones académicas, prensa especializada, estadísticas, entre otras). El análisis de datos es cualitativo y documental. Este artículo comienza con una introducción a la administración del agua en los países árabes. A continuación, se proponen bases teóricas para el estudio de cuencas transfronterizas. Como aporte al marco teórico, se desarrollan los principios sobre cursos de agua compartidos en el Derecho Internacional. A continuación, se presentan las cuencas transfronterizas del país de origen fenicio. Finalmente, se proponen las conclusiones del estudio.

Simulation of Titicaca Lake Water Level Fluctuations Using Hybrid Machine Learning Technique Integrated with Grey Wolf Optimizer Algorithm

Lakes have an important role in storing water for drinking, producing hydroelectric power, and environmental, agricultural, and industrial uses. In order to optimize the use of lakes, precise prediction of the lake water level (LWL) is a main issue in water resources management. Due to the existence of nonlinear relations, uncertainty, and characteristics of the time series variables, the exact prediction of the lake water level is difficult. In this study the hybrid support vector regression (SVR) and the grey wolf algorithm (GWO) are used to predict lake water level fluctuations. Also, three types of data preprocessing methods, namely Principal component analysis, Random forest, and Relief algorithm were used for finding the best input variables for prediction LWL by the SVR and SVR-GWO models. Before the LWL simulation on monthly time step using the hybrid model, an evolutionary approach based on different monthly lags was conducted for determining the best mask of the input variables. Results showed that based on the random forest method, the best scenario of the inputs was Xt−1, Xt−2, Xt−3, Xt−4 for the SVR-GWO model. Also, the performance of the SVR-GWO model indicated that it could simulate the LWL with acceptable accuracy (with RMSE = 0.08 m, MAE = 0.06 m, and R2 = 0.96).

Verification of FPA and PSO algorithms for rule curve extraction and optimization of single- and multi-reservoir systems' operations considering their specific purposes

Abstract The optimal operation of reservoirs is known as a complex issue in water resources management, which requires consideration of numerous variables (such as downstream water demand and power generation). For this optimization, researchers have used evolutionary and meta-heuristic algorithms, which are generally inspired by nature. These algorithms have been developed to achieve optimal/near-optimal solutions by a smaller number of function evaluations with less calculation time. In this research, the flower pollination algorithm (FPA) was used to optimize: (1) Aidoghmoush single-reservoir system operation for agricultural water supply, (2) Bazoft single-reservoir system operation for hydropower generation, (3) multi-reservoir system operation of Karun 5, Karun 4, and Bazoft, and (4) Bazoft single-reservoir system for rule curve extraction. To demonstrate the effectiveness of the FPA, it was first applied to solve the mathematical test functions, and then used to determine optimal operations of the reservoir systems with the purposes of downstream water supply and hydropower generation. In addition, the FPA was compared with the particle swarm optimization (PSO) algorithm and the non-linear programming (NLP) method. The results for the Aidoghmoush single-reservoir system showed that the best FPA solution was similar to the NLP solution, while the best PSO solution was about 0.2% different from the NLP solution. The best values of the objective function of the PSO were approximately 3.5 times, 28%, and 43% worse than those of the FPA for the Bazoft single-reservoir system for hydropower generation, the multi-reservoir system, and the Bazoft single-reservoir system for rule curve extraction, respectively. The FPA outperformed the PSO in finding the optimal solutions. Overall, FPA is one of the new evolutionary algorithms, which is capable of determining better (closer to the ideal solution) objective functions, decreasing the calculation time, simplifying the problem, and providing better solutions for decision makers.

Restructuring China’s Water Environment Management System: A Social Network Perspective

Despite restructuring in institutions related to environmental protection, the multi-sectorial decentralized water management system of China continued to be widely criticized. To identify the problems in China’s water management system and the direction of future reform, this article implemented social network analysis. From multiple perspectives (covering efficiency analysis, condensation analysis, and network centrality analysis), we quantitatively analyzed the structural change of the super-ministry reform of water environment management in China. We found that the 2018 super ministry reform of the system made the aggregation and central enhancement of China’s water management network, hence the power of water environmental management is more concentrated in the core department. However, the function overlap still exists after the reform. Some key issues of water resources management are absent from the responsibility of the core management department. Therefore, the cohesion and management effectiveness of the overall management network need to be further improved. Finally, we summarized several practical implications for future water management system reform, and the kernel is to achieve integrated management of water resource and water environment.

Hydro-Economic Modelling for Water-Policy Assessment Under Climate Change at a River Basin Scale: A Review

Hydro-economic models (HEMs) constitute useful instruments to assess water-resource management and inform water policy. In the last decade, HEMs have achieved significant advances regarding the assessment of the impacts of water-policy instruments at a river basin or catchment level in the context of climate change (CC). This paper offers an overview of the alternative approaches used in river-basin hydro-economic modelling to address water-resource management issues and CC during the past decade. Additionally, it analyses how uncertainty and risk factors of global CC have been treated in recent HEMs, offering a discussion on these last advances. As the main conclusion, current challenges in the realm of hydro-economic modelling include the representation of the food-energy-water nexus, the successful representation of micro-macro linkages and feedback loops between the socio-economic model components and the physical side, and the treatment of CC uncertainties and risks in the analysis.

Assessment of climate change impacts on water balance and hydrological extremes in Bang Pakong-Prachin Buri river basin, Thailand

Among many factors the hydrology of a watershed is mainly influenced by climate and land use change. This study examined the impacts of climate change on water resources and extreme events in the Bang Pakong-Prachin Buri River Basin, Thailand using three different Regional Climate Models (RCMs) ACCESS1-CSIRO-CCAM, CNRM-CM5-CSIRO-CCAM, and MPI-ESM-LR-CSIRO-CCAM under RCP4.5 and RCP8.5 emission scenarios. Soil and Water Assessment Tool (SWAT) was used to simulate the future streamflow and Extreme Value Type I distribution (EVI) was used to analyze the extreme events under projected climate conditions. The result of this study showed an increase in maximum (1.9 °C/3.6 °C) and minimum (1.6 °C/3.3 °C) temperatures under RCP4.5/8.5 at the end of the 21st century. In addition, projected rainfall is expected to decrease up to 6.8% (8.5%) in 2050s and then increase slowly such that the decrement remains 4.2% (11.0%) under RCP4.5 (RCP8.5) at the end of the century. The rainfall pattern is projected to considerably fluctuate, in particular, a shift in long term average annual peak event from September to August is predicted in 2080s under emission scenario RCP4.5 (RCP8.5). On the other hand, the average annual discharge is expected to increase up to 13.5% (2020s) and 7.6% (2050s) under RCP4.5 and RCP8.5 respectively with decreasing trend in low flows and increasing trend in high flows. Further analysis on extreme events; strengthened the results from hydrological modeling with an increase in flow volume for the same return period under changed climate conditions. This raises water resources management issues in the Bang Pakong-Prachin Buri River Basin regarding the frequency of flood and drought events in the future calling for proper policy formulation and implementation.

Precipitation Forecasting Using Multilayer Neural Network and Support Vector Machine Optimization Based on Flow Regime Algorithm Taking into Account Uncertainties of Soft Computing Models

Drought, climate change, and demand make precipitation forecast a very important issue in water resource management. The present study aims to develop a forecasting model for monthly precipitation in the basin of the province of East Azarbaijan in Iran over a ten-year period using the multilayer perceptron neural network (MLP) and support vector regression (SVR) models. In this study, the flow regime optimization algorithm (FRA) was applied to optimize the multilayer neural network and support vector machine. The flow regime optimization algorithm not only identifies the parameters of the SVR and MLP models but also replaces the training algorithms. The decision tree model (M5T) was also used to forecast precipitation and compare it with the results of hybrid models. Principal component analysis (PCA) was used to identify effective indicators for precipitation forecast. In the first scenario, the input data include temperature data with a delay of one to twelve months, the second scenario includes precipitation data with a delay of one to twelve months, and the third scenario includes precipitation and temperature data with a delay of one to three months. The mean absolute error (MAE) and Nash–Sutcliffe error (NSE) indices were used to evaluate the performance of the models. The results showed that the proposed MLP–FRA outperformed all the other examined models. Regarding the uncertainties of the models, it was also shown that the MLP–FRA model had a lower uncertainty band width than other models, and a higher percentage of the data will fall within the range of the confidence band. As the selected scenario, Scenario 3 had a better performance. Finally, monthly precipitation maps were generated based on the MLP–FRA model and Scenario 3 using the weighted interpolation method, which showed significant precipitation in spring and winter and a low level of precipitation in summer. The results of the present study showed that MLP–FRA has high capability to predict hydrological variables and can be used in future research.

Quantifying the impact of climate variables on reference evapotranspiration in Pearl River Basin, China

ABSTRACTThe impact of climate variables on monthly reference evapotranspiration (ETo) is a critical issue in water resources management and irrigation planning. The spatio-temporal contribution of climate variables to ETo in the Pearl River Basin (PRB), China, from 1960 to 2016 were calculated based on sensitivity and relative change of each climatic variable. The results show that annual ETo total decreased by 1.64% and diminished in magnitude from the southeast to the northwest. Sunshine duration, wind speed and relative humidity decreased by 15.5%, 7.4%, and 4.0%, respectively, while average temperature increased by 4.25%. The ETo showed a positive sensitivity to all variables except relative humidity, which showed a negative sensitivity. Sunshine duration had the highest contribution of −4.26%, and the overall decrease in ETo was mainly caused by the declines in sunshine duration and wind speed, which offset the positive impact of rises in average temperature and reduction in relative humidity.

The Role of Dams on Water, Food, and Energy Security Issues: A Global Review and Resolution for Indonesia

Increased water, food, and energy demand due to population growth has contributed linearly to the increasing focus of world concern on dams in many countries. Lately, dams have become an important issue in sustainable water resources management, which have been used for various purposes such as flood control, industrial water supply, irrigation, fisheries, recreation, navigation, hydroelectricity, and other purposes. This study aims to analyze the relationships between variables related to the world's water, food and energy issues, including dams. Multiple linear regression analysis was used to identify the significance of interrelated relationships between variables of water consumption, energy consumption, irrigated areas and the number of dams based on period 1960-2010 data. The results of the analysis concluded that water consumption had the most significant effect on energy consumption and the number of dams. Meanwhile, the number of dams has a significant impact on water consumption, followed by energy consumption. As a resolution for Indonesia, which currently focuses on food and energy security issues, this study recommends that the construction of dams (including large dams) be accelerated.

Transboundary Water Sharing: Risk Perceptions Held by Texas Border Decision Makers

Despite transboundary water resource management issues being a source of tension between neighboring states, little research has addressed what causes cooperation or conflict between differing governments along borders. For the most part, natural hydrological boundaries do not fall easily within political boundary delineations, so governance structures and management approaches are often very different once political jurisdictions are crossed, underscoring the importance of proper management of transboundary water resources. In order to better understand what drives cooperative or conflictual behavior among transboundary stakeholders, a cross-sectional study was conducted along the Texas-Mexico border. Questionnaires were collected (N=168) from Texas water managers along the southern border on issues related to their Mexican counterparts. The results revealed that a lack of trust for binational counterparts is correlated (p<0.001) with a decrease in willingness to cooperate; likewise, as trust decreased, perceptions of risk increased. This approach can help identify a plausible intervention strategy that could target activities that build trust between individuals on both sides of the border to mitigate individuals’ perceptions of risk. Citation: Sansom L. 2019. Transboundary water sharing: risk perceptions held by Texas border decision makers. Texas Water Journal. 10(1):101-111. Available from: https://doi.org/10.21423/twj.v10i1.7095.

Pan evaporation modeling by three different neuro-fuzzy intelligent systems using climatic inputs

Modeling pan evaporation (Epan) estimation is a vital issue in water resources management because it directly affects water reservoir and water supply systems. In the developing countries (e.g., India), Epan data are generally limited, and in such a circumstance, theoretical estimates from available climatic data could be beneficial. The study investigates the capability of three adaptive neuro-fuzzy methods, adaptive neuro-fuzzy inference system (ANFIS)–embedded grid partition (GP), subtractive clustering (SC), and fuzzy c-means clustering (FCM), in estimation of monthly pan evaporation using climatic inputs of minimum and maximum air temperatures, wind speed, sunshine hours, and relative humidity obtained from two stations, Uttarakhand, India. Cross validation method is applied by dividing data into three equal parts, and methods are tested using each part. Methods are evaluated by applying various combinations of inputs and using root mean square error (RMSE), mean absolute error (MAE), Nash–Sutcliffe efficiency (NSE), and determination coefficient (R2) criteria. The ANFIS-FCM is found to be superior to the ANFIS-GP and ANFIS-SC methods in Epan modeling. Cluster-based proposed neuro-fuzzy method increases performance of the best ANFIS-GP and ANFIS-SC models with respect to RMSE by about 9–14% for the both stations. The three ANFIS methods are also compared with each other and Stephen Stewart (SS) method by dividing data into three stages, training, validation, and test. The results indicate the superior accuracy of the ANFIS methods to SS for the same input variables. The ANFIS-FCM generally produces better Epan estimates than the other two ANFIS methods.

Public Attitudes, Preferences and Willingness to Pay for River Ecosystem Services.

River basins are key sources of ecosystem services, with a wide range of social and economic benefits and many effects on human well-being. However, intensified land use and other dramatic variations in river ecosystems can alter ecosystem functions and services. In this study, we explored the public awareness, attitude and perception regarding environmental and water resource issues and assessed the willingness to pay (WTP) for improving selected attributes of the Wei River basin. Various rankings, Likert scales and random parameter logit (RPL) models were used to analyze data obtained from 900 surveyed respondents. Most respondents were more concerned about environmental and water resource management issues rather than socioeconomic attributes. From a policy perspective, 83.32% and 50.50% of the residents ranked “improvement in water quality” and “improving irrigation conditions,” respectively, as their main priorities regarding ecological restoration. Moreover, the results obtained using RPL models showed that the coefficients were significant for all ecological attributes and monetary attributes, as expected. The positive and significant coefficient for the alternative specific constant demonstrated that the respondents preferred restoration alternatives to the status quo. Furthermore, the highest WTP was found for water quality (91.99 RMB), followed by erosion intensity (23.59 RMB) and water quantity (11.79 RMB). Our results are relevant to policy development and they indicate that ecological restoration is the favored option.