State Of Water Resources Research Articles

Application of Water Quality Index in Assessing water Quality: A Case Study of the Shatt Al Arab River.

This investigation pertains to the evaluation of water quality in the Shatt Al-Arab River, located in the Basrah province of southern Iraq, from 2017 to 2022. Its quality should be assessed regularly, and the condition of water resources should be maintained accordingly. The most common analytical method for describing and assessing general water quality is the Water Quality Index (WQI). Various physicochemical parameters like pH, total dissolved solids, total hardness, calcium, magnesium, chloride, and total alkalinity are considered for the present study. The Weighted Arithmetic Water Quality Index Technique is used to evaluate these data. For checking the portability of the parameters within the acceptable limit, WHO is adopted. According to the study mentioned above, the quality has been found to be very low compared to the WQI value. It is also observed that the water was found unsuitable for drinking purposes, and it is considered harmful to human health; therefore, it requires some kind of processing before use. This study will be beneficial to policymakers for identifying and providing details about water quality in the form of a specific value.

Dynamic Changes in Terrestrial Water Balance Using Remote Sensing on the Loess Plateau

In recent decades, the water cycle process in the Loess Plateau has undergone drastic changes under the influence of anthropogenic disturbance and climate variability. The Loess Plateau has been greatly affected by human activities and climate change, and the dynamics of water balance and its key influencing factors remain unknown in this region. To deepen our understanding of water resource status in the Loess Plateau, we analyzed the dynamic changes in the hydrological cycle components and terrestrial water balance via remote sensing during the 2001–2020 period. Moreover, we also discussed the dominant factors affecting the terrestrial water balance. The results indicate that precipitation and ET exhibited increasing trends, with upward rates of 2.56 mm/yr and 5.27 mm/yr, respectively. Spatially, the annual average precipitation and ET showed increasing trends from the north to south. Precipitation in 62.05% of the entire region presented a significant upward trend, with a change rate of 0~2 mm/yr, and the annual change rate of ET in a range of 0~30 mm/year accounted for 89.12%. The runoff exhibited a fluctuating and significantly upward trend during the 2000–2022 period, with a change rate of 3.92 × 108 m3/yr, and was relatively large in the middle reach of the Yellow River. The annual average water consumption in the upper reach of the YRB presented a significant decreasing trend, with a downward rate of −0.06 × 108 m3/yr from 2001 to 2020, and yet it displayed a significant increasing trend in the middle and lower reaches of the YRB with the upward rate of 0.07~0.11 × 108 m3/yr. Based on the principle of water balance, the recharge amount was calculated at less than the discharge amount during the 2001–2020 period, and the difference between recharge and discharge is gradually expanding, with a change rate of −3.72 × 108 m3/yr. The spatial distributions of TWSC revealed that the eastern region was in an imbalanced state, while the western region was in a relatively balanced state. Terrestrial water balance changes were mainly affected by climate factors and human disturbance, and land use/cover change was the dominant factor. The results will be of great significance for optimizing water resource management and formulating various water-saving strategies in the Loess Plateau.

Exacerbating water shortage induced by continuous expansion of surface artificial water bodies in the Yellow River Basin

Aggravated water shortage limits high-quality and sustainable development in the Yellow River Basin (YRB), an important strategic region with a dense population in China. Surface water area (SWA) and terrestrial water storage (TWS) are two crucial indicators of the overall status of water resources in the region, so monitoring their dynamics and drivers is extremely important for sustainable water management under a changing climate and anthropogenic disturbances. Here, we examined the interannual variabilities and trends of SWA and TWS in the YRB during 1990–2021 utilizing all Landsat-5/7/8 surface reflectance observations, Gravity Recovery and Climate Experiment mascon data, a robust water mapping algorithm based on spectral indices and thresholds, and the Google Earth Engine (GEE) cloud computing platform. We found that SWA continuously and substantially expanded (49.67 ± 9.73 km2/yr) in the YRB. The most rapid expansion of SWA occurred in Shandong Province (20.24 ± 1.00 km2/yr), next in the provinces of Henan (15.09 ± 1.16 km2/yr), Shanxi (13.21 ± 1.11 km2/yr), and Shaanxi (4.11 ± 1.07 km2/yr). Quantitative attribution analysis showed that anthropogenic factors, including constructing and extending artificial reservoirs/lakes (42.4 %) and aquaculture ponds (26.5 %), were the major contributors to increased SWA. However, TWS had a significant downward trend (-6.82 ± 0.99 mm/yr) across the entire YRB. Using water evaporation data, we found that evaporation consistently increased (0.07 ± 0.01 km3/yr or 0.16 ± 0.02 mm/yr), which was mainly caused by SWA expansion in Shandong, Henan, Shanxi, Shannxi, Inner Mongolia. We also identified the hotspots with the most rapid increases in evaporative loss, which were in the provinces of Shandong (0.026 ± 0.002 km3/yr) and Henan (0.018 ± 0.001 km3/yr). These losses resulted in a decline of TWS by 1.37 ± 0.11 mm/yr and 0.5 ± 0.05 mm/yr, respectively. Our findings warn that the expanding surface water bodies were not only an illusion of increased freshwater resources in the YRB but also exacerbated the water crisis by accelerating TWS loss through evaporation.

Current Condition of Water Resources and Their Saving

The article presents analytical data on water resources in Uzbekistan and other countries. Based on the system of artificial intelligence, opinions were expressed about the preservation of water resources and the ecosystem in it. Considerations on the wise use of water resources using artificial intelligence, deterministic - stochastic models are presented.

Comparações entre Metodologias para Estimativa de Vazões Mínimas de Referência utilizadas em Concessão da Outorga

The State Water Resources Policy aims to ensure control, for current and future users, of water use and its use in satisfactory quantity, quality and regime. Current legislation provides, as one of the instruments for managing water resources, the granting of the right to use water to its holder for a pre-established period and in a personal and non-transferable manner. As only part of the minimum reference flows can be granted, there is a limitation on the use of water. In periods of lower water availability, it is necessary to analyze the influence of the seasonality of flows in the criteria for granting water use, creating alternatives for the management of water resources. In this context, the present work was carried out with the objective of evaluating and comparing the minimum reference flows and verifying the possibility of an increase in water availability for different users. Data from five fluviometric stations of the Alto Iguaçu and Ribeira watersheds, both located in the state of Paraná, were used, comparing values required by current legislation with those obtained by methodologies used mainly in the United States and Europe Method, Q_7,10Tennant Method, Wet Perimeter Method. The results obtained allowed us to state that the minimum reference flows can be adjusted since the methodologies applied to the same fluviometric stations result in different values for the minimum reference flows.

Simulating the interrelationships among population, water, ecology, and economy in urban agglomerations based on a system dynamics approach

China's urban agglomerations (UAs) gather most of China's population and economy, but they also facing serious water resources crisis and ecological risks. How to manage the interrelationships among the population, water, ecology, and economy (PWEE) in UAs is crucial for the future of China's urbanization development. Based on the system dynamics (SD) approach, we constructed an SD model for simulating the interrelationships among PWEE in UAs, elucidating the intricate nonlinear relationships between elements of the PWEE system through causal feedback processes and model equations. In addition, we take the Tianshan North slope urban agglomeration (TSNSUA) as an example, which is a representative area where water resources crisis and ecological risk coexist, and designed five scenarios to dynamically simulate the balance of water supply and demand under the high-density population and economic agglomeration, as well as the potential ecological environmental effects in the process of urban spatial expansion. Our findings include: (1) The existing water resources conditions of TSNSUA can continue to support the current population and economic growth rates. If the future development plan follows the status quo continuation scenario, the phenomenon of insufficient water supply will not occur on the premise that the water supply capacity remains at its current highest level. (2) TSNSUA's future urban spatial expansion is predicted to have less overall impact on the ecological environment, and the carbon peak target by 2030 has an opportunity to be achieved. (3) Appropriately reducing the proportion of agricultural water, while strengthening water-saving and ecological protection measures, can ensure that TSNSUA's population and economy maintain a medium to high growth rate. Based on scenario comparison, our recommendation to policymakers is to establish the development objectives of TSNSUA based on the comprehensive development scenario.

The environmental state of the Pavlodar region in the Republic of Kazakhstan (1990s)

The article examines the key aspects of the environmental condition of the Pavlodar region in the 1990s. It provides an analysis of the climate, the structure of industrial production, and the availability of minerals. Based on statistical materials, the state of atmospheric air characterized by the presence of harmful impurities polluting the environment has been studied. The status and usage of water resources in the region are also indicated. The authors note a real threat of pollution of the Irtysh River by heavy industry waste in the region. The analysis of the materials showed that despite having significant land resources, the Pavlodar region inefficiently used them for agriculture. In conclusion, it is stated that the environment of the region was influenced by an increase in pollution of water and land resources with toxic metals as a result of the activities of non-ferrous metallurgy and thermal power plants.

The environmental state of the Akmola Region in the Republic of Kazakhstan in the 1990s

The article discusses the environmental issues in the Akmola region during the 1990s. It provides a description of the region’s climate and addresses concerns such as air pollution from both stationary and mobile sources, the condition and use of water resources, radiation levels, and land management. The authors highlight a decline in water quality in lakes attributed to highway construction obstructing the flow of meltwater. Analysis of the data revealed that a significant environmental challenge in the region was the dusting of tailings from the hydrometallurgical plant, leading to further land degradation. In conclusion, it is emphasized that the region’s environmental state was impacted by increased pollution of water and land resources due to activities in mining, processing, chemical, light, and food industries.

Environmental risks assessment of the Kogylnyk River nutrient pollution based on probit functions

The relevance of the study is associated with the need to determine the risks of high and catastrophic levels of water pollution of the Kogylnyk River. The water quality of this river affects the environmental condition of the northern part of Sasyk lake and reservoir. This artificial reservoir that was created as part of the estuary used to be one of components of the Danube-Dniester irrigation system in the past and can be used for irrigation in the post-war period in the future. As the North-Western Black Sea region is an agricultural region of Ukraine, the article focuses on the pollution of the river by specific nutrients (ammonium, nitrite, nitrate, phosphate). The subject of the study covers the environmental risks assessment of the Kogylnyk River present-day pollution. Hydrochemical observations of the State Water Resources Agency of Ukraine were used as input materials of the research. Such observations were carried out across the upper (below the border with the Republic of Moldova) and lower sections of the river. The number of samples taken in the upper section was 80, and 56 – in the lower section. Water quality was assessed using a modified water pollution index (WPI). The risks of nutrient pollution were evaluated based on a statistical approach using a probit function. It was found that the water quality in the upper section is worse than the one in the lower section. The research indicated a close correspondence between water quality indicators and environmental risk values. In the upper section, the risks of catastrophic pollution have a probability of their occurrence that is equal to 46.1%, and the risks of high pollution – 41.1%, with 87.2% constituting a total percentage. In the lower section, the probability of a high level pollution risk is equal to 33.3%, with no critical risk identified during the observation period. The trophic status of the water body along the river length varies from hypertrophic and polytrophic on the upper course to eutrophic and mesotrophic on the lower course. The decrease in pollution levels in the river's lower section is due to the processes of biological, physical and chemical self-purification of the aquatic ecosystem. Since nutrients have a predominantly anthropogenic origin, the water quality improvement of the Kogylnyk River across the territory of Ukraine is associated with the reduced flow of municipal and agricultural wastewater entering the river. Nutrient pollution requires implementation of additional measures such as improving the culture of farming taking place in the catchment area (for example, during conservation of fertilizers and their application).

Analysis of the Status and Rational Allocation of Water Resources in China in View of the New Era

This paper examines the current status of water resource management and conservation in China, along with strategies to address the water resource crisis. Given the current situation, the paper highlights issues such as incomplete legal mechanisms, limited environmental awareness among enterprises, and insufficient government investment. To address these challenges, the paper proposes a series of strategies, including improving the ecological environment, enhancing production techniques, strengthening management systems, rationalizing water resource allocation, and implementing water-saving measures in both industrial and agricultural production. These strategies serve to achieve sustainable water resource management, reduce water pollution, and effectively tackle the pressing water resource issues faced in China currently.

Groundwater Plume Characteristics at Small Chlorinated-Solvent Release Sites in California

There is a need to study the spatiotemporal distribution of chlorinated solvent releases in groundwater to understand the risk/threat they pose to human health, water quality, and the environment, which then can be used to prioritize clean-up and evaluate regulatory closure with appropriate risk management controls. This paper provides a statistical analysis of spatiotemporal distribution of perchloroethylene (PCE) (and its degradation products including trichloroethene [TCE]) from eighty-three cases across California for which data were available onthe State Water Resources Control Board’s GeoTracker database and the Department of Toxic Substance Control Board’s Envirostor database. These cases consisted of seventy-one dry cleaning sites and twelve other similar small solvent release sites. Statistical analyses of available groundwater data were performed to estimate: maximum concentrations at the source area, groundwater plume length, plume stability; and correlations between plume length, concentrations, and plume age. At 90% of the sites, the PCE and TCE plume lengths were less than 1,569 feet (478 meters) and 1,782 feet (543 meters), respectively. The average plume lengths for PCE and TCE were 670 feet (204 meters) and 701 feet (213 meters), respectively. At 90% of the sites that have reached stable conditions, PCE and TCE concentrations at the source areas were less than 2,670 and 660 micrograms per liter (µg/L) respectively. This study for the first time provides key characteristics of small chlorinated-solvent plume behaviors in California that can be used to prioritize management of small chlorinated-solvent release sites and to develop strategies towards achieving closure at these sites.

Comprehensive Evaluation and Coupled Coordinated Development Study of Water–Economic–Ecological Systems in the Five Northwestern Provinces of China

The five northwestern provinces face numerous challenges in sustainable development, particularly water scarcity, economic imbalances, and ecological degradation. This study aims to deeply assess the region’s water resource conditions, the current status of economic development, and the health of the ecosystem while exploring the relationships and coupling mechanisms among them. Using the obstacle model, the research analyzes the primary barriers affecting these three significant factors in the region. The study further reveals a continually improving trend of coordinated development within the water–economic–ecological system in the five northwestern provinces of China, indicating that water usage per ten thousand GDP is the primary obstacle. This research enriches our understanding of the development in China’s five northwestern provinces and provides a theoretical foundation for achieving sustainable development.

Evaluation of Water Resources Carrying Capacity of Zhangye City Based on Combined Weights and TOPSIS Modeling

According to the natural condition of water resources and the economic, social, and ecological environment status of Zhangye City, the water resources carrying capacity of Zhangye City is evaluated by using the water resources carrying capacity Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) model with combination assignment. The results show that: (1) From 2010 to 2020, the water resources carrying capacity of Zhangye City was generally stable at the macro level, ranking at grades III and IV. However, from the micro level, the water resources carrying capacity fluctuates to a certain extent and shows an increasing trend year by year. (2) The steady improvement of economic and social conditions is the main driving force for the improvement of the comprehensive water resources carrying capacity of Zhangye City, and the changes in the ecological environment are also important factors affecting the carrying capacity of water resources. The results provided a decision basis for future comprehensive development and utilization of water resources in Zhangye City and a reference for water resource carrying capacity and water resource security assessment in other arid and semi-arid areas in our country.

Large discrepancy between future demand and supply of agricultural water in northwestern Iran; evidence from WEAP-MODFLOW-machine learning under the CMIP6 scenario

The agricultural sector in northwestern Iran uses about 95 % of the region’s available water resources and nearly 98 % of are aquifer water. Despite the regiońs previous richness in water resources, the supply is now quickly decreasing. The Ghorveh-Dehgolan sub-basin in northwestern Iran consists of three dams as well as three aquifers that supply water resources for agriculture, domestic uses, and industry. We used the Water Evaluation and Planning System (WEAP) and MODFLOW hydrologic model together with machine learning to investigate the status of future water resources in this region under the influence of climate change. At first, the current status of water resources in the area was simulated using WEAP and MODFLOW for the period 2008–2021. Then, the impact of climate change on surface water and groundwater resources in 2026–2045 was evaluated under the SSP2.6 and SSP8.5 emission scenarios. Multivariate Adaptive Regression Splines (MARS) were used to generate future runoff and least-squares support vector regression (LSSVR) was used to predict the groundwater levels for the period 2026–2045. The results showed that under the SSP8.5 scenario, precipitation may decrease by about 15 % in the future compared to the reference period (1987–2005). The reservoir inflow is thus likely to decrease by 25 %, which may decrease the groundwater level by 1.2 m per year in the coming period. The groundwater level in Ghorveh and Dehgolan aquifers dropped by nearly 20 m during the period 2008–2021 and still about 5 to 25 million cubic meters (MCM) of water demand for the agricultural sector were not supplied. If the current trend continues, up to 65 MCM of water demand in the region will not be met in the near future. These results call for immediate action by government and water managers. We outline different alternatives to improve the pessimistic future outlook that can be used to amend the water management in the basin.

Types of Water Rights Systems in China: A Zoning Scheme Applied

This article analyzes the appropriate types of water rights systems for different regions with varying water resource conditions in China. The most appropriate water rights systems for various zones were determined by comparing the value of influencing factors with corresponding thresholds in China’s second-class zones of water resources. It is shown that a riparian rights system under water withdrawals permission could be adopted in most regions of southern China. For most northern Chinese regions, the quantity proportional water rights systems should be adopted and further improved. In contrast to the implementation of a single quantity proportional water rights system, this paper innovatively proposes a zoning scheme for China’s water rights system. The appropriate type of water rights system can be identified according to the region’s specific water resource conditions. It can provide a scientific reference for the reform of water rights systems in China and other countries or regions.

Historical and future runoff changes and their impacts on stormflow characteristics in the upper Yangtze River basin, China

Identifying the contributions of climate- and human-induced impacts on runoff change have aroused broad attention globally in the hydrological cycles and water resource management. However, a systematic quantitative assessment of the impact of climate changes and human activities on historical and future runoff changes in the upper Yangtze River (UYR) and the effects of runoff variation on stormflow characteristics (e.g., annual runoff distribution) remain unclear. Here, we quantified runoff variations and simulated runoff in the UYR using the Soil and Water Assessment Tool (SWAT) hydrologic model and statistical methods. Our main findings include: (1) climate variability played a dominant role in runoff decline in the UYR from 1972 to 2016 (Slope: –0.10 mm/a, P–value < 0.05), accounting for 43.34 % of the total decrease, while anthropogenic activities accounted for 4.82 %; (2) runoff in the upcoming period of 2020–2059 under RCP 2.6, RCP 4.5, and RCP 8.5 will increase significantly (P–value < 0.05) at a rate of 0.14 mm, 0.13 mm, and 0.27 mm per year, respectively; (3) water yield and hydrological drought are all projected to decrease in the entire UYR, but flood frequency will increase under the 1.5 ℃ and 2.0 ℃ global warming. This study provides a new perspective for understanding the status of water resources in the UYR and offers great implications for flood control and effective water resources management over the UYR in the future.

Status, variation, development, and utilization of water resources in China

AbstractThe information about China's water resources yield and its utilization have been publicly released by its annual China Water Resources Bulletin since 1998. This paper introduces the facts of China's water resources and its development and utilization in 2022 and analyzes the variation of water resources, water supply structure, water use volume, and efficiency. In 2022, both precipitation and total volume of water resources in China were less than normal, and were unevenly distributed both temporally and geographically. There has been some decrease in water storage of some large‐ and medium‐sized reservoirs, while the storage of lakes has remained relatively stable. Total water use increased to some extent compared with that in 2021, with further improvements of efficiency and pattern of water uses. There was no significant trend of change on annual precipitation and water resources in China from 1956 to 2022, but the capability of runoff generation in North China showed a decrease. To ensure national water security, China has made great effort to cope with the impacts of climate change and human activities by refined management of surface water resources and groundwater resources, as well as ambitious water‐saving goals.

Application of the Weighted Arithmetic Water Quality Index in Assessing Groundwater Quality: A Case Study of the South Gujarat Region

Groundwater is a natural resource used for drinking, agriculture, and industry, apart from surface water. Its quality should be assessed regularly, and the condition of water resources should be maintained accordingly. The most common analytical method for describing and assessing the general water quality is the Water Quality Index (WQI). This study aims to assess the South Gujarat Region’s groundwater quality using the WQI. Various physicochemical parameters like pH, turbidity, total dissolved solids, total hardness, calcium, magnesium, chloride, sulphate, nitrate, fluorides, and total alkalinity are considered for the present study. The data period from 2018 to 2022 is considered for the same. The Weighted Arithmetic Water Quality Index Technique is used to evaluate these data. For checking the potability of the parameters within the acceptable limit, the Indian Standard Drinking Water Specification code (IS: 10050-2012) is adopted. According to the study mentioned above, a few wells’ groundwater quality has been found to be higher than the WQI value. It is also observed that four wells were found unsuitable for drinking purposes in 2018. It is noted that if the WQI value of groundwater is above 51, it is considered harmful to human health; therefore, it requires some kind of processing before use. This study will be beneficial to the policymakers for identifying and providing details about groundwater quality in the form of a specific value, i.e., WQI.

Sampling frequency optimization of the water quality monitoring network in São Paulo State (Brazil) towards adaptive monitoring in a developing country.

Water quality monitoring networks (WQMNs) that capture both the temporal and spatial dimensions are essential to provide reliable data for assessing water quality trends in surface waters, as well as for supporting initiatives to control anthropogenic activities. Meeting these monitoring goals as efficiently as possible is crucial, especially in developing countries where the financial resources are limited and the water quality degradation is accelerating. Here, we asked if sampling frequency could be reduced while maintaining the same degree of information as with bimonthly sampling in the São Paulo State (Brazil) WQMN. For this purpose, we considered data from 2004 to 2018 for 56 monitoring sites distributed into four out of 22 of the state's water resources management units (UGRHIs, "Unidades de Gerenciamento de Recursos Hídricos"). We ran statistical tests for identifying data redundancy among two-month periods in the dry and wet seasons, followed by objective criteria to develop a sampling frequency recommendation. Our results showed that the reduction would be feasible in three UGRHIs, with the number of annual samplings ranging from two to four (instead of the original six). In both seasons, dissolved oxygen and Escherichia coli required more frequent sampling than the other analyzed parameters to adequately capture variability. The recommendation was compatible with flexible monitoring strategies observed in well-structured WQMNs worldwide, since the suggested sampling frequencies were not the same for all UGRHIs. Our approach can contribute to establishing a methodology to reevaluate WQMNs, potentially resulting in less costly and more adaptive strategies in São Paulo State and other developing areas with similar challenges.

Evaluation of water resources sustainable development in karst area based on the improved emergy ecological footprint model: A case study of Yunnan Province

Abstract This study combined emergy theory with water ecological footprint to analyze and evaluate the sustainable development status of water resources in Yunnan Province from 2012 to 2021. The water pollutant account and the water product account were supplemented to the water ecological footprint. The results showed that the water resources in Yunnan Province were generally in an ecological deficit during the study period, but their absolute values were very small. The ecological pressure index of water resources was high, while the sustainable utilization index of water resources was low, indicating that the water resources were in a state of unsustainable utilization. However, the emergy ecological footprint of water resources and the emergy ecological footprint of water resources of 10,000 Yuan GDP showed a decreasing trend, and the eco-economic coordination index of water resources was relatively high, indicating that the water resources will show a sustainable development trend in the future. The sustainable development of water resources was influenced by both natural ecological factors and social factors. Therefore, suggestions such as improving the utilization rate of water resources development, developing a green low-carbon economy, preventing and controlling water pollution, and protecting the water environment are conducive to promoting the sustainable development of water resources.