Comprehensive Water Resources Management Research Articles

Evaluation and valuation of tajan river basin ecosystem services

Rivers as a blue ecosystem have a lot of ecosystem services that awareness of the value of their services will protect them as much as possible and communities will benefit from their environmental services. In this study, Tajan river basin ecosystem services in the north of Iran was valuated. To valuate, the choice experiment method was used to estimate willingness to pay. Tajan river basin ecosystem services attributes including regulating, supporting, provisioning and cultural services and a price attribute at three levels were determined. Data from 239 resident households of Mazandaran province were used in 2017. The empirical analysis did by the conditional logit model and mixed logit model. Also, multi criteria decision making including techniques Entropy, TOPSIS and SAW used for evaluating the role and importance of the Tajan river basin ecosystem services. The findings indicated that residents were willing to pay for the conservation of Tajan river basin ecosystem services, 13.77 USD per year. It was for regulating, supporting, provisioning and cultural services of Tajan river basin, 2.62, 6.30, 2.50 and 2.35 USD per year to move away from the status quo to the improvement status respectively. Also, findings of weighting and prioritization of Tajan river basin ecosystem services with TOPSIS and SAW methods showed that supporting and provisioning services had the highest weight for the evaluation Tajan river basin ecosystem services. In other words, the residents prefer the services as the most important Tajan river basin ecosystem services. Results showed that willingness to pay can be introduced as a useful tool to investigated people's preference for conservation of river basin ecosystem services under various activities. Therefore, by determining the value of river ecosystem services, community will understand that river services are of great importance, and the application of its value in calculations related to comprehensive management of basin water resources will provide a suitable economic solution to increase user utility the river.

Relative and Combined Impacts of Climate and Land Use/Cover Change for the Streamflow Variability in the Baro River Basin (BRB)

The interplay between climate and land use/cover significantly shapes streamflow characteristics within watersheds, with dominance varying based on geography and watershed attributes. This study quantifies the relative and combined impacts of land use/cover change (LULCC) and climate change (CC) on streamflow variability in the Baro River Basin (BRB) using the Soil and Water Assessment Tool Plus (SWAT+). The model was calibrated and validated with observed streamflow data from 1985 to 2014 and projected the future streamflow from 2041 to 2070 under two Shared Socio-Economic Pathway (i.e., SSP2-4.5 and SSP5-8.5) scenarios, based on the ensemble of four Coupled Model Intercomparison Project (CMIP6) models. The LULCC was analyzed through Google Earth Engine (GEE) and predicted for the future using the Land Change Modeler (LCM), revealing reductions in forest and wetlands, and increases in agriculture, grassland, and shrubland. Simulations show that the decrease in streamflow is attributed to LULCC, whereas an increase in flow is attributed to the impact of CC. The combined impact of LULCC and CC results in a net increase in streamflow by 9.6% and 19.9% under SSP2-4.5 and SSP5-8.5 scenarios, respectively, compared to the baseline period. Our findings indicate that climate change outweighs the impact of land use/cover (LULC) in the basin, emphasizing the importance of incorporating comprehensive water resources management and adaptation approaches to address the changing hydrological conditions.

Evaluation of the Offsets of Artificial Recharge on the Extra Run-Off Induced by Urbanization and Extreme Storms Based on an Enhanced Semi-Distributed Hydrologic Model with an Infiltration Basin Module

Urbanization and climate change exacerbate groundwater overexploitation and urban flooding. The infiltration basin plays a significant role in protecting groundwater resources because it is a prevalent technology of managed aquifer recharge. It could also be utilized as a retention pond to mitigate city waterlogging. The goal of this study was to explore the offsets of artificial recharge on the extra runoff induced by urbanization and extreme storms via infiltration basins. To achieve this objective, a lumped infiltration basin module was developed and integrated into a semi-distributed hydrologic model. Then, the enhanced model was applied to an agriculture watershed with urban areas. Finally, the functionalities of the infiltration basins were evaluated under the scenarios of the predicted urbanization and extreme storms. The results demonstrated the capability of the infiltration basins to influence both artificial recharge and flood mitigation. To mitigate floods, especially peak flows, larger areas are needed for infiltration basins than for artificial recharge purposes only. Based on different demands, the intermittent regulation of infiltration basins according to different hydrologic periods is recommended. The offsets of artificial recharge on the extra surface runoff provide insight into the comprehensive preservation and management of surface water resources and groundwater resources.

Prioritization of sub-watersheds and subsequent site identification for soil water and conservation practices using the SWAT-AHP integrated model in the Lower Sutlej Sub-basin, India.

Prioritization of watersheds is a crucial step in integrated river basin management. It guides resource allocation, planning, decision-making, stakeholder engagement, targeted interventions, and monitoring and evaluation efforts. By identifying and addressing priority watersheds, comprehensive and sustainable management of water resources can be achieved within a river basin. The aim of the current study is to prioritize watersheds using the Soil and Water Assessment Tool (SWAT) and site suitability analysis for the implementation of soil and water conservation structures (SWCS) in the prioritized watersheds by using an analytical hierarchy process (AHP) of the Lower Sutlej Sub-basin, India. The model was calibrated with observed data from 2017 to 2019 with the first 2years (2015-16) as a warm-up period. Furthermore, validation of the model was done using 2-year data from 2020 to 2021. The model showed successful performance in terms of the R2 range from 0.72 to 0.89, the NSE range from 0.67 to 0.73, the PBIAS range from - 26.70 to 11.30, and the RSR range from 0.51 to 0.57 for stream flow and sediment yield during calibration and validation period. The basin's average annual soil loss ranged from 3.08 to 21.63 t/ha/year, a watershed with the WS2 index seeing the highest rate of soil erosion (21.63 t/ha/year). Hence, WS2 was found to be a top priority. In addition, the site suitability analysis of the prioritized watershed (WS2) reveals that about 1.42% of the area is extremely suitable, 16.14% is highly suitable, and 35.58% is moderately suitable for SWCS. According to the site suitability map validation, both dam locations were found in highly suitable areas, so the developed site suitability map is accurate. This research will help sustainability planners and managers make more informed decisions when building SWCS at suitable sites for better land and water conservation.

A system dynamics simulation-based strategic analysis of integrated water resources utilization and management in Shenzhen city.

As one of the most rapidly developing cities in China, Shenzhen grapples with an increasing challenge in managing water resources due to escalating conflicts with its soaring water demand. This study established a system dynamics (SD) model based on a causal loop diagram to explore the intricate interconnections within the urban water resources system. Through simulating water supply and demand in Shenzhen from 2021 to 2035, the model identified key sensitive factors and examined various utilization scenarios for multiple water resources. Results indicated that water scarcity posed a significant obstacle to Shenzhen's development. To tackle this challenge, several effective measures should be implemented, including enhancing water conservation capabilities, developing seawater resources, promoting water reuse, optimizing the economic structure, and managing population growth. Prioritizing water conservation efforts and maximizing the utilization of seawater resources were regarded as the most impactful strategies in alleviating the water crisis. Furthermore, the relationship between water conservation capabilities and seawater utilization scale was analyzed using the SD model, contributing to the development of a comprehensive water resources management strategy. The findings from this study would provide insights into robust methods for allocating water resources, thereby enhancing sustainable water management strategies applicable to regions facing similar challenges.

Application of a Linked Hydrodynamic–Groundwater Model for Accurate Groundwater Simulation in Floodplain Areas: A Case Study of Irtysh River, China

The rich biodiversity in the floodplain area is influenced by both floodplain floods and groundwater (GW). To protect the ecological environment in the floodplain area, it is essential to study the interaction between floodplain floods and GW. The objective of this paper is to propose a coupling strategy between a hydrodynamic model and a GW model to provide an accurate simulation tool for quantifying the interaction between floodplain floods and GW. The case study is conducted in the floodplain area of the middle reaches of the Irtysh River in northwest China. Firstly, a two-dimensional hydrodynamic model based on TELEMAC-2D is constructed to accurately simulate floodplain floods under wetting and drying conditions. Secondly, a GW model based on MODFLOW is developed. Finally, a coupling strategy is proposed to achieve accurate and efficient integration between the hydrodynamic model and the GW model. The calibration and verification results of the model demonstrate high accuracy, with root mean squared error (RMSE) values of 0.51 m and 0.77 m between observed and calculated GW levels for the hydrodynamic–GW coupled model. The water balance results indicate that floodplain floods serve as the largest GW recharge source in the study area, while phreatic evaporation is the primary GW discharge item. This paper represents a novel attempt to couple a two-dimensional hydrodynamic model with a GW model. The research results provide a scientific tool for the ecological restoration of floodplain areas considering both surface water and GW, as well as the comprehensive management and regulation of wetland water resources and the water environment.

Review Analysis of Irrigation and Application of Remote Sensing in the Lower Mekong River Basin

Irrigated agriculture is indispensable to the Lower Mekong River Basin (LMB), which ensures food security and provides livelihoods for tens of millions of people. Irrigation, agricultural production, hydropower and aquatic ecosystem health are intertwined in LMB, so it is necessary to adopt a holistic approach to analyze irrigation problems. Here, we discuss the challenges and opportunities of LMB irrigation. Bibliometric analysis is carried out to determine the characteristics and patterns of watershed irrigation literature, such as the importance of authors, affiliated institutions, and their distribution in China. Based on bibliometric analysis, research topics are determined for thematic review. Firstly, we investigated the factors that directly affect the demand and supply of irrigation water and associated crop yield impacts. Secondly, we analyzed the influence of water availability, land use and climate change on agricultural irrigation. Thirdly, we analyzed the adverse effects of improper irrigation management on the environment, such as flow pattern change, ecosystem deterioration and land subsidence caused by groundwater overexploitation. Fourthly, the time–space mismatch between water supply and demand has brought serious challenges to the comprehensive water resources management in cross-border river basins. In each specific application area, we sorted out the technologies in which remote sensing technology is used. We hope that this review will contribute to in-depth research and decision analysis of remote sensing technology in agricultural irrigation.

A Data-Driven Framework for Spatiotemporal Analysis and Prediction of River Water Quality: A Case Study in Pearl River, China

Characterization of the spatiotemporal water quality variation is of utmost importance for water resource management. Changes in water quality have been shown to be significantly affected by uncertain factors such as environmental conditions and anthropogenic activities. However, few studies consider the impact of these variables on water quality prediction while developing statistical methods or machine learning algorithms. To solve the problem, a data-driven framework for the analysis and prediction of water quality in the Guangzhou reach of the Pearl River, China, was constructed in this study. The results provided evidence of a discrepancy in the spatiotemporal dynamics of water quality, with the average water quality index (WQI) values ranging from 52.47 to 83.06, implying “moderate” to “excellent” water quality at different stations. Environmental conditions and anthropogenic activities exerted great influence on the alteration of water quality, with correlation coefficients of 0.6473–0.7903. The relevant environmental factors and anthropogenic drivers combined with water quality variables were taken into account to establish the attention-based long short-term memory (LSTM-attention) model. The proposed LSTM-attention model achieved reliable real-time water quality prediction with up to a 3-day lead-time and a determination coefficient (R2) of 0.6. The proposed hybrid framework sheds light on the development of a decision system for comprehensive water resource management and early control of water pollution.

Loosely-coupled Collaboration of Policy Implementation in China: A Case Study on the Governance Policy of S River Basin

Successful river basin governance is challenged by actor engagement in the various stages of planning and management. Water governance has been handled as a critical national issue in China since ancient times. Over thousands of years, water governance in China has evolved from flood control, irrigation, and navigation to modern large-scale water supply, water pollution control, and ecological protection, with sustainable water resources management being the major challenge today. Although these issues vary significantly across the country, China has adopted a national, unified approach to manage water resources in a river basin context. In particular, over the last 70 years, China’s water governance has experienced fundamental changes. These commonalities show that designs are fundamental to tackle geographic and sectoral fragmentation of complex systems and catalyze the emergence of adaptive water governance. This study comparatively analyses the advantages of the policy in basin environmental governance, such as clear government responsibility, enhanced coordination among government departments, the accountability mechanism of the one-vote veto system, and the disadvantages of the policy in terms of high costs, information asymmetry, and lack of public participation. Furthermore, this study proposes suggestions on the sustainable development of watershed environmental governance from three aspects: regional characteristics, investment, and institutional innovation of policy implementation. Hence, this research is an important scientific foundation for the authorities to build cooperative water resource management programs in transboundary river basins. In future research, the availability of a more detailed dataset will enable the construction of a more comprehensive water resource management plan for different phases.

INDICATOR OF SUSTAINABLE WATER RESOURCES USE IN THE TRANSBOUNDARY BASINS

Due to the complex situation of integrated water resources management in transboundary river basins, this research built a set of indicators for sustainable use of water resources by the Delphi method and developed a specific calculation method for 22 indicators of 5 groups. The integrated indicator has 5 assessment levels to demonstrate the magnitude of water use and the renewability of water resources. Using these indicators to evaluate the sustainability of three border provinces in the Mekong transboundary basin which are Kontum, Attapue, and Ratanakiri, this research came to the conclusions that 9/24 districts in three provinces have moderate water use and renewable water resources level; the remaining districts are also using water at a moderate level but with low renewable water resources. Furthermore, research results showed that different governmental policies generated varying impacts on the sustainable use of water resources in three provinces. Hence, this research is an important scientific foundation for the authorities to build cooperative water resource management programs in transboundary river basins. In future research, the availability of a more detailed dataset will enable the construction of a more comprehensive water resource management plan for different phases.

Spatial and temporal dynamics of water resources in typical ecosystems of the Dongjiang River Basin, China

In hydrology research, how to quantitatively analyze the spatial and temporal changes of water resources in the ecosystem of a watershed is one of the focuses of attention. Especially in the strategically important Dongjiang River Basin, which is the source of water for three world-class cities of Hong Kong, Shenzhen and Guangzhou. Hence, it is important to quantitatively analyze the spatial and temporal variation of water resources at the basin and ecosystem scale of Dongjiang river basin. The Soil and Water Assessment Tool (SWAT) was used in this study to analyze the spatial and temporal dynamics of typical ecosystem water resources in the Dongjiang River basin over the last 50 years. The objectives of the study were to: (1) identify the distribution of water resources in typical ecosystems; (2) determine the quantity of water in the forest ecosystem; and (3) characterize the spatial and temporal changes. The findings revealed that: (1) the average water resources in the Dongjiang River Basin from 1971 to 2020 were 37.944 Bm3, and there were obvious changes in the basin’s total quantity of water resources. The most important climatic factors influencing water resources were precipitation and temperature. (2) From 1971 to 2020, the total water resources of typical Donjiang River Basin ecosystems exhibited a declining trend. The total average water resources of the forest ecosystem were 27.532 Bm3, which first increased and then decreased from upstream to downstream. The total quantity of water resources in the grassland ecosystem increases with the amount of water per unit area. (3) The change in total water resources has been decreasing over the last decade, which is consistent with the change in the water resources of the forest ecosystem in the Dongjiang River Basin. Changes in water resources were greater in the lower and middle reaches than in the upper reaches. Changes in land use were a significant factor in the evolution of water resources in typical ecosystems. This study can provide theoretical support for the comprehensive management of typical ecosystems and water resources in the Dongjiang River Basin.

Application of Stacking-Based Ensemble Learning Model for Water Quality Prediction

Water is the source of life, and the growth of animals and plants cannot leave the water source. The quality of water will directly affect the life and health of humans, animals and plants. In order to predict the concentration and changing trend of various pollutants in water bodies and promote the comprehensive management of water resources, this paper proposes a new integrated model based on the idea of Stacking integrated learning. The model is based on XGBoost, support vector regression, and multi-layer perceptron. The model is constructed with ridge regression as the meta-model. The model was applied to the pH and total nitrogen content of water quality, and the mean absolute percentage error was used to quantitatively evaluate the prediction results, and the results of the ensemble learning model were compared with the prediction results of a single base model. The results show that the stacking ensemble learning idea can effectively improve the prediction ability and generalization performance of the base model. The proposed ensemble learning model has very good prediction ability and generalization ability, and has great potential in other prediction fields such as water quality.

Simulation of water and carbon coupling of the Pearl River basin based on the WaSSI model

Watershed water and carbon cycles are closely linked through plant photosynthesis and evapotranspiration (ET). Simulation of coupled water-carbon cycles at the watershed scale is important for the comprehensive management of water and carbon resources. By improving the WaSSI (water supply stress index) eco-hydrological model, we established and verified a water-carbon coupling simulation model for the Pearl River Basin in south China (WaSSI-PRB). The Pearl River Basin was divided into 1715 watersheds. The simulations of three water-carbon flux parameters, such as runoff, ET and gross primary productivity (GPP), were verified with 1980-2004 as the calibration period and 2005-2016 as the validation period. The Nash-Sutcliffe efficiency coefficient (NSE) and the coefficient of determination (R2) of the simulated runoff at the controlling hydrological stations of Xijiang, Beijiang and Dongjiang were greater than 0.80 during calibration period and greater than 0.75 during validation period. Compared with MODIS, PML, SSEBop, VPM and other large-scale remote sensing data products, WASSI-PRB showed a better performance in capturing the spatiotemporal variations of ET and GPP. In general, WaSSI-PRB model had good applicability in the study area, and could be used as an effective tool to quantitatively analyze water-carbon balance and their responses to environmental changes in the Pearl River Basin.

Combining Isotope and Hydrogeochemistry Methods to Study the Seawater Intrusion: A Case Study in Longkou City, Shandong Province, China

In order to study hydrogeochemical effect in the process of seawater intrusion (SI), and provide scientific basis for comprehensive management of water resources and water ecological restoration, the Longkou city of Shandong province in China was taken as an example in this study. Based on the observed data, traditional hydrogeochemistry methods of hydrochemistry analysis, correlation analysis, principal component analysis, and reverse geochemical simulation was firstly comprehensively combined with stable isotope tracing in Longkou city, and this is the first study to use the isotope method to study SI in the study area. The results showed Cl− had high correlation with Na+, Mg2+, and K+. The hydrochemical types of groundwater in Longkou city were mainly HCO3.Cl-Na.Ca, and HCO3.Cl-Ca, showing the evolution of HCO3-Ca to HCO3.Cl-Na to Cl-Na from the inland to the coastline. Stable isotopes analysis with δ2H, δ18O and 87Sr/86Sr indicated the main source of groundwater was atmospheric precipitation. The SI degree was the strongest at the junction of the west and north coast zones, with high values of δ2H and δ18O. The high Sr2+ concentration of groundwater was mainly from SI and groundwater–rock interactions. In the SI process, the mixing of seawater and fresh water took place first, and then different degrees of cation exchange and mineral dissolution and sedimentation occurred. Results of reverse hydrogeochemical simulation showed dolomite and quartz precipitated, with negative migrated masses of 1.38 × 10−3 and 1.08 × 10−5 mol/L on simulation Path 1, respectively, where calcite, halite, and gypsum dissolved with positive migrated masses of 2.89 × 10−3, 3.52 × 10−3, and 4.66 × 10−4 mol/L, respectively, while dolomite and gypsum precipitated and calcite, halite, and quartz dissolved on simulation Path 2. On simulation Path 3, the dolomite, gypsum, halite, and quartz were dissolved, and calcite was precipitated, with a negative migrated mass of 1.77 × 10−4 mol/L.

Water resources carrying capacity model and prediction in Shandong Province based on social and economic factors

In this paper, considering the influence of economic, social, resource and environmental factors on water resources in Shandong Province, a fuzzy comprehensive evaluation model of water resources carrying capacity is established based on DPSIR index system, to evaluate the annual change of water resources carrying capacity in Shandong Province. Then the main influencing factors of total social water consumption are obtained by grey correlation, and the functional relation of total social water consumption is established on regression model. Finally, the development trend of social total water consumption is predicted by time series. The results show that: the development and utilization of water resources in Shandong Province has reached a very high level, water resources are in the stage of scarcity, and the shortage of water resources will continue to intensify in the future. Therefore, it is suggested that comprehensive water resources management policies should be formulated to save and use water resources intensively, in order to ensure the optimal allocation and scientific sustainable utilization of water resources in Shandong Province.

Spatial and temporal characteristics of China’s water footprint of energy and its matching relationship with water resources

Energy and water resources are very important for human survival and social development. Energy and water footprint can reflect the real occupation of water resources in the process of energy production. Based on the energy and water footprint evaluation model, this paper calculates the life cycle water footprint of fossil energy and power production in 30 provinces (cities and autonomous regions) in China, studies the temporal and spatial pattern evolution characteristics of China’s raw coal, crude oil, natural gas, hydropower and thermal power from 2004 to 2016, and analyzes the spatial matching relationship between China’s energy and water footprint and water resources. The results show that: (1): during the study period, the water footprint of fossil energy increases first and then decreases with 2012 as the boundary. The rapid growth of hydropower water footprint promotes the continuous growth of power water footprint. (2): In terms of spatial pattern, the water footprint of fossil energy increases in the West and decreases in the East with the Huhuanyong line as the boundary, and the Inner Mongolia, Shanxi and Shaanxi region as the high-value concentration area; in the power water footprint, there is a significant spatial boundary between hydropower water footprint and thermal power water footprint. The rapid growth of hydropower water footprint has gradually formed a high-value concentration area of power water footprint in the Yangtze River Basin, the Pearl River Basin and the southeast coast. (3): The spatial matching degree of energy and water footprint and water resources fluctuates and declines in the pattern of high in the south and low in the north. The spatial matching degree of fossil energy and water footprint is lower than that of electric power and water resources. The energy water contradiction between raw coal production and thermal power generation is the most prominent. One third of the country has the problem of energy water mismatch. North China with high energy and water footprint has great pressure on energy water matching. The contradiction between energy production and water resources allocation still exists. Truly reflect the matching relationship between energy and water footprint and water resources, help to optimize the comprehensive management of energy and water resources, and provide a quantitative basis for maximizing the energy water synergy.

Adaptability of machine learning methods and hydrological models to discharge simulations in data-sparse glaciated watersheds

The accurate simulation and prediction of runoff in alpine glaciated watersheds is of increasing importance for the comprehensive management and utilization of water resources. In this study, long short-term memory (LSTM), a state-of-the-art artificial neural network algorithm, is applied to simulate the daily discharge of two data-sparse glaciated watersheds in the Tianshan Mountains in Central Asia. Two other classic machine learning methods, namely extreme gradient boosting (XGBoost) and support vector regression (SVR), along with a distributed hydrological model (Soil and Water Assessment Tool (SWAT) and an extended SWAT model (SWAT_Glacier) are also employed for comparison. This paper aims to provide an efficient and reliable method for simulating discharge in glaciated alpine regions that have insufficient observed meteorological data. The two typical basins in this study are the main tributaries (the Kumaric and Toxkan rivers) of the Aksu River in the south Tianshan Mountains, which are dominated by snow and glacier meltwater and precipitation. Our comparative analysis indicates that simulations from the LSTM shows the best agreement with the observations. The performance metrics Nash-Sutcliffe efficiency coefficient (NS) and correlation coefficient (R2) of LSTM are higher than 0.90 in both the training and testing periods in the Kumaric River Basin, and NS and R2 are also higher than 0.70 in the Toxkan River Basin. Compared to classic machine learning algorithms, LSTM shows significant advantages over most evaluating indices. XGBoost also has high NS value in the training period, but is prone to overfitting the discharge. Compared with the widely used hydrological models, LSTM has advantages in predicting accuracy, despite having fewer data inputs. Moreover, LSTM only requires meteorological data rather than physical characteristics of underlying data. As an extension of SWAT, the SWAT_Glacier model shows good adaptability in discharge simulation, outperforming the original SWAT model, but at the cost of increasing the complexity of the model. Compared with the oftentimes complex semi-distributed physical hydrological models, the LSTM method not only eliminates the tedious calibration process of hydrological parameters, but also significantly reduces the calculation time and costs. Overall, LSTM shows immense promise in dealing with scarce meteorological data in glaciated catchments.

Research on Optimal Operation of Reservoirs in Shule River Irrigation District Based on Dynamic Programming with Successive Approximation Method

Reservoir operation is an important means to realize optimal allocation of water resources. In order to reasonably distribute water resources in Shule River irrigation area and improve the utilization rate of water resources, according to the actual situation of Shule River irrigation area, taking the minimum annual water shortage and the highest irrigation guarantee rate of the whole irrigation area as the objective function, the deterministic long-term optimal operation model of reservoir group in the irrigation area is established, and the successive approximation dynamic programming ( DPSA ) is used to solve the problem, so as to realize the joint operation of Changma Reservoir, Shuangta Reservoir and Chijinxia Reservoir, and provide the basis and reference for the comprehensive management and scientific allocation of water resources in Shule River basin.

Water Resource Management for Sustainable Urban Development

Water resource management is a crucial aspect of sustainable urban development, considering the increasing global urbanization and the growing need for efficient water management. This abstract explores the importance of water resource management in promoting sustainable urban development, emphasizing the need for integrated and holistic approaches. It highlights key strategies, challenges, and opportunities associated with water resource management, aiming to achieve long-term environmental, social, and economic sustainability.Effective water resource management is imperative for sustainable urban development due to its significant impact on various aspects of urban life. Urban areas are experiencing escalating water demands due to population growth, industrialization, and changing lifestyles. The limited availability of freshwater resources and the vulnerability of urban ecosystems necessitate proactive measures to ensure the sustainability of water resources. The implementation of comprehensive water resource management strategies can contribute to mitigating water scarcity, protecting water quality, and preserving aquatic ecosystems.

Determination of the amount of Sanitary Water Flow from Dams based on the Quality of Drinking Water: A Case Study, Taleghan River, Iran

Background: Given the crisis of water shortage and the industrial development in Iran, comprehensive water-resource management and planning to handle the water quality of the rivers are the critical issues to tackle with. The concentration of river pollutants is a function of both the quantity and quality of the river flow regime. In this regard, the construction of large dams leads to quantitative and qualitative changes in downstream rivers. These changes are effective in the health of the river water for uses such as drinking, agriculture, and industry. Therefore, in addition to the quantity of water needs of rivers, their quality needs to be also considered. Objectives: This study aimed to analyze issues related to the sanitary water flow of large dams. Our case study was the Taleghan River dam, Alborz Province, Iran, on which Taleghan reservoir was built to supply some part of the water needed by Greater Tehran, Iran. Methods: This study examined a 22-km long section of the river at the riffle of Taleghan Dam in Alborz Province (103 km from Karaj), Iran. The average annual and monthly discharges of the river in four 6-km-apart stations were estimated. The statistics of eight hydrometric stations and a discharge-surface method were used to calculate the average annual discharge of each sub-basin downstream of Taleghan Dam. Moreover, the discharge non-dimensionalization method, along with the observational statistics of the index station, was used to calculate the average monthly discharge in the examined stations. The Hydrologic Engineering Centers River Analysis System (HEC-RAS) software (version 4.0) was then utilized to determine the values ​​of river flow rates hydraulically. Additionally, water quality parameters were compared with the standard concentrations proposed by the World Health Organization (WHO) for drinking-water quality to examine possible changes in pollutant concentrations during the study. Correlation and regression statistical tests in SPSS software (version 24) were then used to analyze the relationship between discharge and pollutant concentration. Results: The experimental equation of Q = 0.0372A0.8641 was obtained to estimate the discharge based on the sub-basins area using the discharge-surface method. The average annual discharge at stations 2, 3, and 4 (B, C, and D) were estimated at 1.39, 2.11, and 3.39 m3/s, respectively, using this equation. Subsequently, the average monthly discharges in the studied stations in September were calculated at 0.21, 0.29, and 0.46 m3/s, respectively. Afterward, the discharge was measured using HEC-RAS software (version 4.0) in the same month at 0.34, 0.44, 0, and 0.62 m3/s, respectively. The examination of water quality values from ​​among the 17 water quality parameters revealed that physicochemical elements, pH concentration, lead (Pb), and electrical conductivity were higher than the standard concentration of drinking water proposed by the WHO. Conclusion: A model was presented to estimate sanitary water flow by performing correlation tests and linear regression calculations between the river discharge at the dam downstream and the concentration of water quality parameters. According to the proposed model, the minimum flow of sanitary water was estimated at 1.82 m3/s to be considered to release from the dam in the driest month of the year. Therefore, the release of water as the minimum flow of sanitary water less than 1.82 m3/s was not allowed in any other month of the year.