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The countries within the Nile Basin have become increasingly water stressed with each passing year due to the intensification of climate change, and disagreements about water allocation rights between these countries only exacerbate the issue. For about a century, Ethiopia and Egypt have been quarrelling over rights to the Nile’s waters with no resolution in sight. In 2011, Ethiopia began construction of the Grand Ethiopian Renaissance Dam (GERD), which increased tensions. As of 2023, the dam’s construction was completed but negotiations have made no meaningful progress. The dam worsens political relations but impacts the environment, economy, and society in both positive and negative ways. Considering these impacts and the example of the demolition of the Klamath River dams, it was determined that dam demolition would be the most beneficial and equitable course of action, in the long run, for all the Nile River riparian countries. A policy memo was then constructed advocating for demolition of the GERD.

Abstract: Water diversions for agriculture reduce ecosystem services provided by saline lakes around the world. Exposed lakebed surfaces are major sources of dust emissions that may exacerbate existing environmental inequities. This paper studies the effects of water diversions and their impacts on particulate pollution arising from reduced inflows to the Salton Sea in California via a spatially explicit particle transport model and changing lakebed exposure. We demonstrate that lakebed dust emissions increased ambient and concentrations and worsened environmental inequalities, with historically disadvantaged communities receiving a disproportionate increase in pollution. Water diversion decisions are often determined by political processes; our findings demonstrate the need for distributional analysis of such decisions to ensure equitable compensation.

Agricultural water consumption security is crucial for maintaining food production stability. Aiming to investigate water consumption efficiency and objectives in agricultural and non-agricultural sectors, we adopted a Budyko-analogous framework to establish an optimal water allocation model based on the maximum water utilization benefits principle. The proposed Budyko framework was verified through its application in Anhui Province, China, and the difference in water utilization efficiencies among different regions was discussed. The research findings can be concluded as follows: (1) during 2011–2020, the provincial agricultural productive loss caused by per-unit water shortage was lower compared to non-agricultural sectors, and this trend was adaptive in the south but totally opposite in the north; (2) the guaranteed level of agricultural water consumption was higher compared to non-agricultural sectors in the north due to the predominance of agricultural production but totally contrary in the south. Overall, the above findings are consistent with the actual industrial structure of Anhui Province. [ABSTRACT FROM AUTHOR]

Male and female dioecious plants often show sexual dimorphism, differing in morphological, physiological and life‐history traits. Most previous studies have focused on differences between males and females during or after reproduction, paying little attention to the pre‐reproductive stages of the individuals. Here we assessed the response of male and female individuals of the dioecious plant Silene latifolia to abiotic stress at different life stages, including pre‐reproductive (i.e. seedlings and young plants) and reproductive individuals. We measured growth, resource allocation and discrimination against 13C under nutrient deficiency, water stress, as well as their interaction. We observed sexual dimorphism in root growth, with female seedlings having longer main roots than male plants. Pre‐reproductive male and female plants also responded differently, in terms of root allocation, to nutrient and water availability. At reproduction, females grew more roots than males when water was not limiting. These differences could help explain the female‐skewed sex ratios found in natural populations of S. latifolia. We found no evidence of sexual dimorphism in aboveground dry mass, although females had longer leaves than males at the seedling stage. We conclude that sexual dimorphism in S. latifolia may occur not as a consequence of reproduction, but well before it. [ABSTRACT FROM AUTHOR]

Seomijn River Basin has numerous hydraulic structures designed to satisfy water demands and mitigate future droughts. However, the increasing water demand and export to neighboring areas cause water deficits and conflicts between water users. Therefore, practical strategies to mitigate the potential damage from climate change are essential. In this study, we aimed to propose practical strategies under climate change by examining the future water security of the Seomjin River Basin under five different water allocation scenarios referenced from the practical policies of various countries. Future climate models determined based on extreme precipitation indices of the ETCCDI were used to investigate their impact on water security, which was evaluated using unmet demand; demand coverage; reliability, resilience, and vulnerability; and aggregation index metrics. We found that prioritizing domestic and industrial water use is the optimal water security strategy, and unconditional allocation of instream flow can cause a significant water deficit for other water uses. However, prioritizing all water uses equally also proved effective under some conditions. Thus, our study highlights the importance of adaptive management and suggests that the optimal water allocation strategy lies in its flexibility in response to varying circumstances. [ABSTRACT FROM AUTHOR]

In 1956 the U.S. National Park Service (NPS) launched Mission 66, a ten-year program to rebuild and improve infrastructure within hundreds of units of the National Park System, among them Death Valley National Monument in California. As elsewhere, plans in this unit centered on a visitor center, new employee housing, administrative and maintenance facilities, and campgrounds. The original plans developed for Death Valley were abruptly changed, leading to allegations that the NPS was involved in a deal with a resort in the park, in which the NPS would receive a land donation in exchange for overlooking illegal use of monument water by the resort. This Great Death Valley Mission 66 Conspiracy reached the ears of Congress, and in 1962 Congressional hearings were held to investigate these matters. The NPS director and many others were called to give testimony. This story gives a fascinating glimpse into the development of Mission 66 facilities in a large park, and how the plans for these facilities depended on an underlying geography of land ownership, water rights, dubious surveys, and expectations by faraway bureaucrats; these in turn reveal much about possibilities and limitations on opportunities for park development. The Mission 66 facilities in Death Valley have stood the test of time and remain central to visitation in the park to this day. [ABSTRACT FROM AUTHOR]

ABSTRACT Despite considerable experimental effort, the physiological mechanisms governing temperate tree species' water and carbon dynamics before the onset of the growing period remain poorly understood. We applied 2H‐enriched water during winter dormancy to the soil of four potted European tree species. After 8 weeks of chilling, hydrogen isotopes in stem, twig and bud water were measured six times during 2 consecutive weeks of forcing conditions (Experiment 1). Additionally, we pulse‐labelled above‐ground plant tissues using 2H‐enriched water vapour and 13C‐enriched CO2 7 days after exposure to forcing conditions to trace atmospheric water and carbon uptake (Experiment 2). Experiment 1 revealed soil water incorporation into the above‐ground organs of all species during the chilling phase and significant species‐specific differences in water allocation during the forcing conditions, which we attributed to differences in structural traits. Experiment 2 illustrated water vapour incorporation into all above‐ground tissue of all species. However, the incorporation of carbon was found for evergreen saplings only. Our results suggest that temperate trees take up and reallocate soil water and absorb atmospheric water to maintain sufficient above‐ground tissue hydration during winter. Therefore, our findings provide new insights into the water allocation dynamics of temperate trees during early spring. [ABSTRACT FROM AUTHOR]

This study investigated the current and potential future impact of climate change on water resources in the Minjiang River Basin, Fujian Province, China. Coupling a statistical downscaling model (SDSM) model and the Soil and Water Assessment Tool (SWAT) model, and considering the Coupled Model Intercomparison Project (CMIP) CMIP5 Representative Concentration Pathway (RCP) RCP2.6, RCP4.5, and RCP8.5 scenarios, we found a notable upward trend (2.9%, 7.5%, and 12.3% increase, respectively) in multiyear average runoff. A system dynamics feedback model was applied to optimize water resource allocation for Fuzhou, Sanming, and Nanping cities in the Minjiang River Basin, considering the runoff predicted by the SWAT model under climate change. The prediction results show that industrial water use steadily decreases, whereas water consumption in the tertiary sector increases concurrently. By 2050, water allocation schemes have reached the level of moderately developed countries, with these schemes taking into consideration the constraints imposed by red lines for water usage upper limit in China. These findings provide insights into the current and potential challenges posed by climate change, and can guide effective water resource planning for Minjiang River Basin cities. [ABSTRACT FROM AUTHOR]

Water infrastructures are critical assets that ensure communities served by them have access to clean and reliable water. Because the cost of creating a water infrastructure is relatively high and the service life of infrastructures ranges from a few decades to more than a century, the process of systematic maintenance and rehabilitation is essential for preserving them at an optimal functioning capacity. From an asset management perspective, water infrastructure maintenance and rehabilitation (M&R) decision-making primarily involves assessing the condition and performance of the infrastructure, accounting for aspects such as complying with regulatory requirements, allocating resources based on system constraints, and mitigating network failure risks. The existing frameworks for water infrastructure maintenance and rehabilitation rely on models that allocate resources for M&R operations based on network condition and criticality under budgeting constraints. However, existing M&R frameworks have not included social equity (e.g., fair and just distribution of water resources) as a variable that directs or influences the M&R decisions. To improve the equitability of water infrastructures, a framework that incorporates social equity into the M&R decision-making is needed to attain equitable resource allocations for M&R projects. Hence, in this study, we developed a framework that optimizes resource allocations for water infrastructure M&R decisions by directly incorporating social equity objectives. The developed social equity objectives were derived from four social equity theories, utilitarianism, Rawlsianism, egalitarianism, and socialism, and integrated into three different policies A, B, and C, to (1) maximize performance, (2) maximize performance and improve access to disadvantaged groups, and (3) minimize the gap in performance between the disadvantaged group and the rest of network, respectively. The developed framework was applied to a numerical case study of a water distribution pipeline network in the City of Portland, Oregon, and the results of the modeling were discussed. The case study findings indicate that Policies B and C, which are equity inclined, without causing considerable economic setbacks result in a smaller performance disparity between the condition scores of assets in privileged (advantaged) versus underprivileged (disadvantaged) neighborhoods. The study results provide evidence that quantitatively incorporating social equity into the decision-making of water infrastructure M&R can improve asset allocations to disadvantaged communities without significantly compromising the broader network's performance. [ABSTRACT FROM AUTHOR]

The increasing occurrence of prolonged droughts and extreme wet events in California poses significant challenges to the management of the region's water resources. To address these challenges, the utilization of Flood-Managed Aquifer Recharge (Flood-MAR) has emerged as a potential solution. This study developed a multiobjective hydroeconomic model to assess the economic impact of implementing Flood-MAR and reoperation of Folsom reservoir within the American River Basin. The simulation module consists of a hydrological model and a linear programming groundwater recharge model. The economic impact evaluation considers three main components: the value of groundwater recharge, surface storage, and hydropower generation. The findings demonstrate that the adoption of Flood-MAR and reoperation of Folsom reservoir offer considerable economic benefits, with minimal adverse effects on the downstream system. Two different model solutions were analyzed: one that aimed to maximize recharge and storage benefits, and one that prioritized hydropower generation. The former exhibited an increase in reservoir storage compared with historical operation, along with increased water allocation for groundwater recharge during wet and normal years. The latter showed substantial gains in hydropower generation but occasional drops in reservoir storage below historical levels. Despite these differences, the solution emphasizing recharge and storage benefits was deemed to be more realistic, considering the risk of future droughts and uncertainties in climate and hydrological forecasts. Overall, this research provides a foundation for assessing the economic impact of Flood-MAR implementation in the Folsom reservoir system. [ABSTRACT FROM AUTHOR]

In arid and semi-arid regions like Iran, sustainable urban and agricultural development is intimately intertwined with the severity, frequency, and duration of meteorological droughts. Prolonged meteorological droughts can trigger hydrological and socio-economic droughts, posing significant challenges to the region's sustainability. Therefore, the primary objective of this study is to perform a comprehensive Regional Frequency Analysis (RFA) for extreme meteorological drought events across Iran. To this end, we meticulously calculated the severity, duration, and magnitude of the Standardized Precipitation Index (SPI) over the 3-, 6-, 9-, and 12-month accumulation periods. The data was derived from monthly precipitation records collected at 106 meteorological stations during the period spanning 1993–2016. Subsequently, we employed a rigorous approach, utilizing Ward's clustering analysis and the test for heterogeneity using L-moment, to effectively classify and categorize the extreme drought characteristics prevalent across the country. The analysis revealed that the generalized Pareto and Pearson type 3 models are the most suitable distribution functions for RFA across almost all the examined clusters. Additionally, the spatiotemporal analysis of the SPI series at various time scales indicated that the extreme events' characteristics, such as severity, duration, and magnitude, remain surprisingly unaffected by the local climate conditions. The results also showed that even in the typically humid regions located in the north, west, and northwest of Iran, areas that receive considerable annual precipitation, severe droughts can still occur. These droughts primarily stem from temporal events rather than being solely dependent on the local climate conditions. Therefore, the study concludes that the drought events can largely be attributed to mismanagement and inadequate regional water allocation. Moreover, these situations might have been further exacerbated by the occurrence of extreme climatic conditions. [ABSTRACT FROM AUTHOR]

In recent years, due to the shortage of water resources and the fragile ecological environment in arid areas, the relationship between vegetation and water resources has been relatively close. The unreasonable allocation of water resources and the excessive demand for ecological water use have led to ecological and environmental problems such as river interruption, land desertification, and the extensive withering of vegetation in arid areas; therefore, rapid, accurate estimation of the vegetation ecological water demand has become a hot research topic in related fields. In this study, we classified the land use types in the lower reaches of the Kokyar River Basin based on Sentinel-2A data and calculated the water requirements of each type of vegetation using a combination of the area quota method and improved Penman–Monteith (PM) based on different vegetation coverage levels. The results revealed that in 2020, the water demand of planted woodlands within 0–2 km of the watershed will be the highest, and the water demand of naturally growing arboreal woodlands will be the lowest, and the water demand of the surrounding desert riparian vegetation forests will be very small in relation to the ecological base flow and will not affect the downstream water use for agriculture, industry, and domestic use for the time being. The ecological water demand of the vegetation in the study area can be accurately estimated using Sentinel-2A data, and the research results provide technical support and a theoretical basis for rapid estimation of the ecological water demand of vegetation in typical riparian forests in arid areas and for the allocation of water resources. [ABSTRACT FROM AUTHOR]

Neoliberal approaches to water governance, pioneered in Chile in the 1980s, are reappearing today on the centerstage of the water policy debate. While advocates claim that strong property rights, limits on government authority, and water markets can enhance environmental sustainability, efficiency, neutrality, and equity in the distribution of water rights, limited empirical evidence exists on whether neoliberal policies have delivered on these key promises. In this paper, we combine hydrological analysis with a nationwide data set on government water rights allocations between 1981 and 2021 to determine when and where water has been allocated beyond sustainable limits. We then integrate water market transaction and agricultural data to assess how allocations and scarcity conditions relate to spatial and temporal patterns in irrigation, crop distribution, and water market activity. Our results indicate that 30% of catchments are overallocated, and that continued government allocations of water rights during scarcity exacerbate already‐high inequalities in the distribution of water. We find no evidence that scarcity or water markets induced improvements in numerous efficiency metrics. Overall, our results support growing claims that the neoliberal water model fails to fulfill its key promises, notably to the detriment of nature and marginalized rural communities. Plain Language Summary: In this paper, we assess how and to what extent the neoliberal model for water policy‐as manifested through Chile's 1981 Water Code‐has delivered on its promises of environmental sustainability, efficiency, neutrality, and equity. We integrate hydrological analysis with a data set of nationwide water rights allocations between 1981 and 2021 to determine which catchments have been overallocated beyond sustainable limits. We then bring in novel data sets of water market transactions, crop distribution, and irrigation patterns to investigate how these overallocations relate to water market activity, various metrics of water efficiency, and equity in the distribution of water rights. Our findings of widespread overallocation, high inequality in water ownership, and lack of market‐induced efficiency improvements contributes to growing claims that the neoliberal model has failed to fulfill its key promises. Key Points: The free‐market water model in Chile has largely failed to deliver on its key promisesWater scarcity conditions create new opportunities for uneven water rights accumulationThe State plays a crucial role in distributing water‐even when and where markets should theoretically dominate [ABSTRACT FROM AUTHOR]

This paper develops an actionable interdisciplinary model that quantifies and assesses uncertainties in water resource allocation under climate change. To achieve this objective, we develop an innovative socio-ecological grand ensemble that combines climate, hydrological, and microeconomic ensemble experiments with a widely used decision support system for water resource planning and management. Each system is populated with multiple models (multi-model), which we use to evaluate the impacts of multiple climate scenarios and policies (multi-scenario, multi-forcing) across systems so as to identify plausible futures where water management policies meet or miss their objectives and to explore potential tipping points. The application of the methods is exemplified by a study conducted in the Douro River basin (DRB), an agricultural basin located in central Spain. Our results show how marginal climate changes can trigger non-linear water allocation changes in the decision support systems (DSSs) and/or non-linear adaptive responses of irrigators to water shortages. For example, while some irrigators barely experience economic losses (average profit and employment fall by < 0.5 %) under mild water allocation reductions of 5 % or lower, profit and employment fall by up to 12 % (∼ 24 ×) when water allocation is reduced by 10 % or less (∼ 2 ×). This substantiates the relevance of informing the potential natural and socio-economic impacts of adaptation strategies and related uncertainties for identifying robust decisions. [ABSTRACT FROM AUTHOR]

The Ghrib Basin is currently encountering water-related challenges due to population growth and growing competition among water users. Therefore, assessing the current water situation is essential for the anticipation of future needs in the region. This paper assesses water demand and allocation strategies in the Ghrib Basin, Algeria, using the Water Evaluation and Planning (WEAP) system. The simulation is based on five scenarios: "Increase in population and agricultural activity", "Improving agricultural activity", "Minimum domestic consumption", "Enhancing Water Resources", and "Best practice", (which is a combination of two scenarios, i.e., "Improving agricultural activity" and "Minimum domestic consumption"). The simulation outcomes indicate that the "Best practice" scenario represents the most advantageous and beneficial scenario by which the problem of the unmet demand can be solved. The resulting simulations indicated the need for the employment of water-efficient irrigation systems as well as the encouragement of sustainable water use, such as drip irrigation, which necessitates coordinated efforts and particular infrastructural investments. The derived outcomes are highly convincing and have the potential to serve as a decision support system for the effective governance of water resources in the Ghrib Basin. The methodology utilized in this study has the potential to be implemented in any basin across the globe. [ABSTRACT FROM AUTHOR]

Cooperative and self-enforceable water allocation is a key instrument to manage geopolitical conflict induced by water scarcity, which necessitates the cooperative willingness of the agents and considers their heterogeneity in geography, climate, hydrology, environment and social economy. Based on a multi-indicator system that contains asymmetric information on water volume contribution, current water consumption, water economic efficiency and efforts for eco-environmental protection, this study proposed a water allocation framework by combining the asymmetric power index approach with bankruptcy theory for solving the transboundary water allocation problem under scarcity. The proposed method was applied to the Yellow River Basin in northern China, which is mainly shared by nine provincial districts and frequently suffers from severe water shortages, and its results were compared with six alternative methods. The results highlight the necessity of quantifying agents' willingness to cooperate under the condition of asymmetric negotiation power when making decisions on transboundary water allocations. The proposed method allows for transboundary water allocations through simultaneous consideration of the agent's willingness to cooperate and asymmetric negotiation power, as well as disagreement allocation points, which ensure the stability, fairness and self-enforceability of allocation results. Therefore, it can offer practical and valuable decision-making insights for transboundary water management under water scarcity. [ABSTRACT FROM AUTHOR]

The ecological water demand is of crucial importance for the health and sustenance of oasis ecosystems in arid and semi-arid regions. This study utilized the area quota method, phreatic evaporation method, and plant evapotranspiration method to estimate the ecological water demand of natural vegetation and analyze the temporal and spatial distribution characteristics of ecological water demand in the Aksu River Irrigation District. The results indicated that the current ecological water demand of forestland and grassland is 1.011–1.251 × 108 and 2.429–2.761 × 108 m3, respectively. Moreover, the ecological water demand of forestland and grassland under the restoration target was 2.243–2.776 × 108 and 2.594–2.948 × 108 m3, respectively. The vegetation ecological water demand exhibited a significant seasonal difference, with summer > spring > autumn > winter. The spatial distribution of vegetation ecological water demand was wide and significantly different, with noticeable high-value areas and low-value areas. The phreatic evaporation method and vegetation evapotranspiration method were deemed reasonable and reliable for calculating the appropriate ecological water demand and maximum ecological water demand of vegetation, respectively. The research results hold significant value in guiding natural vegetation restoration, regional water resources allocation and regulation of ecological water demand in the Aksu River Basin. [ABSTRACT FROM AUTHOR]

This article explores Indigenous knowledge on N'bi. It examines differing worldviews and discusses what Indigenous knowledge is and how Indigenous Peoples have been sharing their knowledge. This article discusses Anishinaabek approaches to N'bi and responsibilities to N'bi that include responsibilities to the celestial beings. Indigenous Peoples have been sharing their knowledge on N'bi through Declarations and scholarly articles primarily drafted by Indigenous Peoples themselves. The knowledge shared commonly explains that N'bi is alive with responsibilities. The Declarations explain women are responsible for N'bi and offer solutions for the inclusion of Indigenous knowledge in water decision‐making regimes.This article is categorized under: Human Water > Water Governance Science of Water > Water and Environmental Change Human Water > Rights to Water [ABSTRACT FROM AUTHOR]

Clarifying the impact of driving forces on multi-temporal-scale (annual, quarterly and monthly) runoff changes is of great significance for watershed water resource planning. Based on monthly runoff data and meteorological data of the Jialing River (JLR) during 1982–2020, the Mann–Kendall tendency testing approach was first applied to analyze variation tendencies of multi-timescale runoff. Then, abrupt variation years of runoff were determined using Pettitt and cumulative anomaly mutation testing approaches. The ABCD model was employed for simulating hydrological change processes in the base period and variation period. Finally, influences of climatic and anthropic factors on multi-scalar runoff were computed using the multi-scalar Budyko formula. The following conclusions were drawn in this study: (1) The mutation year of discharge was 1993; (2) the monthly runoff in the JLR presented a "single peak" distribution, and the concentration degree and concentration period in the JLR both showed an insignificant reduction trend; (3) anthropic factors were the dominant factor for spring runoff variations; climatic factors were the dominant factor on annual, summer, fall and winter runoff variations; (4) except for November, climatic factors were the dominant factor causing runoff changes in the other 11 months. This study has important reference value for water resource allocation and flood control decisions in the JLR. [ABSTRACT FROM AUTHOR]

The Han River Ecological Economic Belt (HREEB) has a substantial amount of water resources; however, its distribution is uneven, and issues such as seasonal and engineering water shortages are prevalent. This necessitates a thorough assessment of the current water resource situation and trends in water resource carrying capacity (WRCC) to provide scientific support for the rational allocation of water resources. This study employed the RAGA-PP model to establish a WRCC evaluation index system composed of four subsystems: water resources, economy, society, and the ecological environment. The WRCC of the 17 major cities in the HREEB was evaluated from 2008 to 2022. The differentiation method was introduced to compare the reliability of the RAGA-PP model with three evaluation methods: the entropy weight TOPSIS method, the rank sum ratio method, and the principal component analysis method. In addition, an obstacle degree model was introduced to analyze the factors influencing WRCC enhancement. The results indicated the following. (1) In the differentiation test of the four models, the RAGA-PP model was found to have the highest differentiation value, and the results showed that it was more reliable in the WRCC evaluation of HREEB. (2) WRCC in the HREEB underwent significant changes between 2008 and 2022. (3) The WRCC in Shiyan and Wuhan, which are located in the eastern part of the HREEB, were high in Hubei, low in four cities in Henan, and satisfactory in three cities in Shaanxi. (4) The carrying capacity of the subsystems of the cities in the HREEB exhibited fluctuating changes with obvious internal variations. (5) The problems in the WRCC guideline layer were consistent across all cities in the HREEB, with limited per capita water resources being the primary issue in the indicator layer. Assessing WRCC is essential for achieving sustainable water resource use and high-quality regional development. [ABSTRACT FROM AUTHOR]

Influenced by increasing global extreme weather and the uneven spatiotemporal distribution of water resources in monsoon climate areas, the balance of agricultural water resources supply and demand currently faces significant challenges. Conducting research on the spatial allocation trade-offs and synergistic mechanisms of agricultural water resources in monsoon climate areas is extremely important. This study takes the spatial layout of reservoir site selection in water conservancy projects as an example, focusing on Shandong Province as the research area. During the site selection process, the concept of water resource demand is introduced, and the suitability of reservoir siting is integrated. It clarifies ten influencing factors for suitability degree and five influencing factors for demand. A bi-objective optimization model that includes suitability degree and demand degree is established. Utilizing machine learning methods such as the GA_BP neural network model and the GA-bi-objective optimization model to balance and coordinate the supply and demand relationship of agricultural water resources in the monsoon region. The study found that: (1) in the prediction of suitability degree, the influencing factors are most strongly correlated with the regulatory storage capacity (regulatory storage capacity > total storage capacity > regulating storage coefficient); (2) compared with single-objective optimization of suitability degree, the difference between water supply and demand can be reduced by 74.3% after bi-objective optimization; (3) according to the spatial layout optimization analysis, the utilization of water resources in the central and western parts of Shandong Province is not sufficient, and the construction of agricultural reservoirs should be carried out in a targeted manner. This study provides new ideas for promoting the efficient use of water resources in monsoon climate zones and the coordinated development of humans and nature, reflecting the importance of supply and demand balance in the spatial allocation of agricultural water resources, reducing the risk of agricultural production being affected by droughts and floods. [ABSTRACT FROM AUTHOR]

Research on evapotranspiration and its drivers in the Aksu River Basin from the perspectives of climate change and land use is of great significance for promoting the efficient use and precise allocation of its water resources. Theil-Sen median trend analysis (T-S) and the Mann–Kendall nonparametric test (M-K), in addition to correlation analysis, partial correlation analysis, complex correlation analysis, and driving-factor zoning principles, were used to examine the characteristics of the spatiotemporal changes in evapotranspiration and to explore the driving mechanism of the changes in evapotranspiration. The results indicated that the range of fluctuations in the multiyear average evapotranspiration in the Aksu River Basin from 2001 to 2020 was between 481.58 and 772.37 mm/a, which showed the spatial distribution characteristics of being high in the west and central part of the basin, and low in the north and south of the basin. The positive correlation between evapotranspiration and precipitation was stronger, and the negative correlations with temperature and relative humidity were stronger. The change in evapotranspiration in cultivated land is mainly driven by precipitation and relative humidity × precipitation; for grassland, the main drivers were relative humidity and precipitation × relative humidity; for woodland, the main drivers were relative humidity and other climatic factors; and for other land types, the main drivers were other climatic factors. [ABSTRACT FROM AUTHOR]

Lake Urmia is one of the world's largest hyper-saline lakes, which has faced a severe drop in water level in the last three decades. To study the effects of irrigated agriculture development on the hydrology of the Lake Urmia basin, a regional climate model, RegCM, was used to simulate the hydroclimate of the basin under different land use and land cover (LULC) scenarios. The findings demonstrated that the growth of irrigated agriculture increases actual evapotranspiration, and affects other components of water and energy balances. Under the past scenario, the lake's water right is fully provided. But, under the current scenario, only about 42.2% of the lake's water right is supplied, and under the future scenario, even the agricultural sector will face a water deficit. Regarding the implementation of the Urmia Lake Restoration Program (ULRP) strategy of reducing water consumption by 40% in the agricultural sector, 59.8% and 15.3% of lake's water right is provided under current and future scenarios, respectively and if other solutions (water transfer from Kani Sib dam and Silweh dam) are used, 85.3% and 40.8% of the lake's water right is supplied under current and future scenarios, respectively. Considering the effect of climate change on the hydroclimatic conditions of the basin, it is necessary to study the combined effects of LULC change and climate change on the water balance of Lake Urmia. [ABSTRACT FROM AUTHOR]

Agroecosystems are facing the adverse effects of climate change. This study explored how the ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) can give new insight into irrigation allocation and plant health. Leveraging the global coverage and 70-m spatial resolution of the Evaporative Stress Index (ESI) from ECOSTRESS, we processed over 200 overpasses and examined patterns over 3 growing seasons across the Maipo River Basin of Central Chile, which faces exacerbated water stress. We found that ECOSTRESS ESI varies substantially based on the overpass time, with ESI values being systematically higher in the morning and lower in the afternoon. We also compared variations in ESI against spatial patterns in the environment. To that end, we analyzed the vegetation greenness sensed from Landsat 8 and compiled the referential irrigation allocation from Chilean water regulators. Consistently, we found stronger correlations between these variables and ESI in the morning time (than in the afternoon). Based on our findings, we discussed new insights and potential applications of ECOSTRESS ESI in support of improved agricultural monitoring and sustainable water management. [ABSTRACT FROM AUTHOR]

Copyright of Tecnología y Ciencias del Agua is the property of Instituto Mexicano de Tecnologia del Agua (IMTA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study aimed to forecast dam inflows and subsequently predict its capability in producing HEPP using machine learning and evolutionary optimization techniques. Mahabad Dam, located in the northwest of Iran and recognized as one of the nation's key dams, served as a case study. First, artificial neural networks (ANN) and support vector regression (SVR) were employed to predict dam inflows, with optimization of parameters achieved through Harris hawks optimization (HHO), a robust optimization technique. The data of temperature, precipitation, and dam inflow over a 24-year period on a monthly basis, incorporating various lag times, were used to train these machines. Then, HEPP from the dam was predicted using temperature, precipitation, dam inflow, and dam evaporation as input variables. The models were applied to data covering the years 2000 to 2020. The results of the first part indicated both hybrid models (HHO-ANFIS and HHO-SVR) improved the prediction performance compared to the single models. Based on the results of Taylor's diagram and the error evaluation criteria, the HHO-ANFIS hybrid model (RMSE, MAE, and NSE of 3.90, 2.41, and 0.86, respectively) exerted better performance than HHO-SVR (RMSE, MAE, and NSE of 4.39, 2.70, and 0.86, respectively). The results of the second part showed that using the HHO algorithm to optimize single models (RMSE, MAE, and NSE of 0.2, 10, and 0.90, respectively) predicted HEPP better than single models (RMSE, MAE, and NSE of 0.2, 10, and 0.90, respectively). The results of Taylor's diagram also showed that the HHO-ANFIS model exerted better performance. The findings of this study indicated the promising performance of machine learning models optimized by metaheuristic algorithms in the simultaneous prediction of dam inflows and HEPP in multi-purpose dams for better management and allocation of surface water resources. [ABSTRACT FROM AUTHOR]

A new methodology, called HY4RES models, includes hybrid energy solutions (HESs) based on the availability of renewable sources, for 24 h of water allocation, using WaterGEMS 10.0 and PVGIS 5.2 as auxiliary calculations. The optimization design was achieved using Solver, with GRG nonlinear/evolutionary programming, and Python, with the non-dominated sorting genetic algorithm (NSGA-II). The study involves the implementation of complex multi-objective and multi-variable algorithms with different renewable sources, such as PV solar energy, pumped hydropower storage (PHS) energy, wind energy, grid connection energy, or battery energy, and also sensitivity analyses and comparisons of optimization models. Higher water allocations relied heavily on grid energy, especially at night when solar power was unavailable. For a case study of irrigation water needs of 800 and 1000 m3/ha, the grid is not needed, but for 3000 and 6000 m3/ha, grid energy rises significantly, reaching 5 and 14 GWh annually, respectively. When wind energy is also integrated, at night, it allows for reducing grid energy use by 60% for 3000 m3/ha of water allocation, yielding a positive lifetime cashflow (EUR 284,781). If the grid is replaced by batteries, it results in a lack of a robust backup and struggles to meet high water and energy needs. Economically, PV + wind + PHS + grid energy is the most attractive solution, reducing the dependence on auxiliary sources and benefiting from sales to the grid. [ABSTRACT FROM AUTHOR]

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Having a consistent and readily available clean water supply is essential, not only for convenience but also to safeguard public health. While disruptions to the supply of clean water can impact communities of all kinds, some infrastructures and healthcare facilities are more vulnerable than others, such as those located in remote areas or within First Nations communities. This paper presents a case study of water disruption events within Sechelt and the First Nations community of Bella Bella, describing also the associated response efforts and lessons learned. Both events shared similar response activities, requiring the curtailing of normal water usage, the establishment of emergency operations centres, the sourcing of resources via supply chain or transportation partners, implementation of infection prevention and public health considerations, and collaboration with internal and external agencies. The learnings highlight a need for greater focus on building resiliency within healthcare facilities, especially those that serve remote or First Nations communities. The study also presents recommendations for water disruption response planning at the site and community level, and the establishment of non-centralised backup water systems. [ABSTRACT FROM AUTHOR]

In this paper we address governmentality and the politics of water rights by examining the Nevada Division of Water Resources (the Division)’s governance associated with water indicators and accounting practices. We are specifically interested in the political work of water indicators and accounting practices as they are produced, applied, and contested – work that generates advantages for Nevada’s mining industry. We focus on perennial yield, an important indicator used by the Division, and examine accounting practices in which mining water rights are designated as temporary and nonconsumptive. We examine how these water indicators and accounting practices are deployed in ways that 1) make groundwater legible and apportionable in ways that advantage the mining industry; 2) reduce the visibility of mining access to groundwater; and 3) enhance the resource state’s objectivity and legitimacy.

In this review, we use legal scholarship to explore the way that the law constructs and maintains discourses on both water rights and water relationality. Water rights and water relationality can be constructed as opposite ends of a spectrum of legal modalities for defining and regulating the human/water relationship. However, when considered through the lens of law, rights and relationality can also be seen as intertwined. The legal instruments that create individual rights to take and use water situate those rights within frameworks that regulate the relationship between humans (both collectively and individually) and between humans and the water ecosystem. We begin with an identification and exploration of three water rights discourses in legal scholarship: water as a private right (to take and use), the human right to water, and the rights of rivers. We then consider emerging legal scholarship on the more complex reality of water relationality, focusing on the role of law in water commoning, Indigenous laws, and environmental restorative justice. In doing so, we identify points of intersection between these discourses as mediated through law. We also identify critiques of both water rights and water relationality discourses in law and the ways in which they shape our ability to respond to water crises.

As legal battles over surface water allocation in Klamath County, Oregon, USA have gained national attention, earning the name "Water Wars," authorities have been increasingly turning to groundwater to compensate for water shortfalls. This case study aims to identify the nuanced perspectives of household groundwater well users who are affected by groundwater extraction. Using Q methodology, we uncover groundwater well users' perceptions and to what extent they think water problems are dealt with fairly. We identify four water perspectives that differ in the degree to which respondents prioritize clean water accessibility, industry accountability, individual responsibility for water management, and trust in governments to manage water competently. This research contributes to the growing body of literature reshaping our understanding of human-water relations by exploring different water axiologies. [ABSTRACT FROM AUTHOR]

Accurate long–term water resource supply simulation and demand estimation are crucial for effective water resource allocation. This study proposes advanced artificial intelligence (AI)–based models for both long–term water resource supply simulation and demand estimation, specifically focusing on the ShihMen Reservoir in Taiwan. A Long Short–Term Memory (LSTM) network model was developed to simulate daily reservoir inflow. The climate factors from the Taiwan Central Weather Bureau's one–tiered atmosphere–ocean coupled climate forecast system (TCWB1T1) were downscaled using the K–Nearest Neighbors (KNN) method and integrated with the reservoir inflow model to forecast inflow six months ahead. Additionally, Multilayer Perceptron (MLP) and Gated Recurrent Unit (GRU) were employed to estimate agricultural and public water demand, integrating both hydrological and socio–economic factors. The models were trained and validated using historical data, with the LSTM model demonstrating a strong ability to capture seasonal variations in inflow patterns and the MLP and GRU models effectively estimating water demand. The results highlight the models' high accuracy and robustness, offering valuable insights into regional water resource allocation. This research provides a framework for integrating AI–driven models with Decision Support Systems (DSSs) to enhance water resource management, especially in regions vulnerable to climatic variability. [ABSTRACT FROM AUTHOR]

During the dry season, river flow gradually diminishes, and surface water flow dries up. Therefore, the investigation of runoff during the dry season is of great practical significance for rational water allocation and water resource management. Based on hydrological station data from the Xijiang River Basin (XRB) from 1961 to 2020, this study examines the trend and periodic characteristics of dry-season runoff, identifies fluctuation and variability in dry-season runoff, and investigates the main circulation factor combinations influencing dynamic changes in dry-season runoff. The results indicate the following: (1) the characteristics of dry-season runoff variations are basically consistent across sub-basins in the XRB during the study period, with the minimum (21.96 × 108 m3) and maximum (54.67 × 108 m3) average monthly runoff occurring in February and October, respectively; (2) interannual-scale dry-season runoff exhibits periodicity of 3.53 years and 7.5 years; (3) using the Bayesian estimator of abrupt seasonal and trend change algorithm (BEAST), a seasonal abrupt point with a probability of 20.5% occurs in 1983, and the confidence interval for this abrupt point is from 1980 to 1986; (4) based on the cross wavelet approach, solar sunspots are identified as the primary circulation factor contributing to dry-season runoff in the XRB, exhibiting a significant 8–14 years resonance cycle of negative correlation with runoff during the high-energy phase from 1972 to 2006. These findings offer a new perspective on understanding the evolution of dry-season runoff and circulation factor variations, which are crucial for accurate prediction, early warning, and rational allocation of water resources during the dry season. [ABSTRACT FROM AUTHOR]

The present study explores the strategic siting of hydroelectric power plants, focusing on the Miyanaka Intake Dam (MID) and Shinano River Hydroelectric Power Station (SHP). Built in 1939 to support Tokyo's railway electrification, these facilities demonstrate the complexities of balancing renewable energy production with ecological conservation. Despite the high costs and energy losses associated with transmitting power from the Sea of Japan side, the SHP has effectively powered Tokyo's rail system for over 80 years, owing to advanced transmission technologies and the region's abundant water resources. However, river-crossing structures such as dams disrupt fish migration and habitats, necessitating the implementation of fishways. The MID fishway, continually improved since its construction, emphasizes the importance of integrating ecological considerations into hydropower projects. Our findings highlight the higher power generation efficiency on the Sea of Japan side and stress the need for careful site selection to ensure sustainable hydroelectric power while preserving river ecosystems. In conclusion, hydropower sites should be chosen based on both environmental impacts and future development potential to maintain the ecological balance and support long-term renewable energy goals. [ABSTRACT FROM AUTHOR]

Water resources managers need to make decisions in a constantly changing environment because the data relating to water resources are uncertain and imprecise. The Robust Optimization and Probabilistic Analysis of Robustness (ROPAR) algorithm is a well-suited tool for dealing with uncertainty. Still, the failure to consider multiple uncertainties and multi-objective robustness hinders the application of the ROPAR algorithm to practical problems. This paper proposes a robust optimization and robustness probabilistic analysis method that considers numerous uncertainties and multi-objective robustness for robust water resources allocation under uncertainty. The copula function is introduced for analyzing the probabilities of different scenarios. The robustness with respect to the two objective functions is analyzed separately, and the Pareto frontier of robustness is generated. The relationship between the robustness with respect to the two objective functions is used to evaluate water resources management strategies. Use of the method is illustrated in a case study of water resources allocation in the Huaihe River basin. The results demonstrate that the method opens a possibility for water managers to make more informed uncertainty-aware decisions. [ABSTRACT FROM AUTHOR]

Reflecting on the 2023 assertion by the Global Commission on the Economics of Water that the depletion of blue water by irrigation contributes to the global water crisis, we critique two previous contributions by one of its authors, Johan Rockström. First, to bridge agro-meteorological drought, rainfed (green water) farmers should irrigate. If not regulated, this increases water withdrawals and depletion. Second, the continuum of agricultural water management is a field-scale emphasis on rainfall and/or irrigating to top up soil moisture. This emphasis hinders taking a multi-scale irrigation systems approach to resolve blue water depletion and its inequitable impacts. [ABSTRACT FROM AUTHOR]

The protection of Chile's rivers is a matter of ongoing public and constitutional interest in the wake of Chile's failed 2019–2024 constitutional reforms. In this article we review and evaluate opportunities for greater legal protection and restoration of rivers in Chile. The legal analysis was complemented by a survey of social attitudes about river protection needs and several interviews with key experts and stakeholders, which found strong concern for enhanced river protection mechanisms in Chile. We conclude by outlining critical pathways towards durable legal protections for the future of Chile's rivers. [ABSTRACT FROM AUTHOR]

Irrigated areas are major vectors of agricultural development and components of ecosystems. The groundwater level maintains the irrigated areas' ecology safety and sustainable development. Under the influence of irrational irrigation practices—such as flood irrigation or extreme water saving without consideration of ecological impact—different areas within an irrigation district may experience anomalies in groundwater levels (either too deep or too shallow). It is of great significance to carry out research on water resource allocation and future water-saving strategies, taking into consideration groundwater depths. In this study, a method for the optimal allocation of irrigation water resources that considered groundwater level was used to regulate irrational irrigation practices and to reveal the future direction of water saving. Helan County in Ningxia province, an ecologically fragile and arid irrigated area, was selected as a case study. Multiple scenarios of different water use and different degrees of water-saving were analyzed. The results showed that non-engineering water-saving measures (such as adjusting the planting structure and controlling the amount of irrigation for rice) had better benefits compared to engineering measures (such as efficient water-saving irrigation and channel lining). When implementing only one water-saving measure, the strategy of replacing 75% of the rice area with corn yielded the best results. This approach can reduce the irrigation water shortage rate to 11% and increase by 4.58% the acreage where the groundwater level is reasonable. When multiple water-saving measures are implemented together, the most effective strategy for future water-saving efforts involves the joint implementation of several measures: replacing 75% of the rice area with corn, limiting irrigation for rice to no more than 11.85 thousand m3/ha, adopting high-efficiency water-saving irrigation in 90% of the pump-diverted water irrigation region and 40% of the channel-diverted water irrigation region, and maintaining the channel's water utilization coefficient at 0.62. This strategy can keep the irrigation water shortage below 3.66% and increase the acreage where the groundwater level is reasonable, by 4.58% per year. The conclusions and research approaches can provide references for the formulation of water-saving measures for irrigated areas' sustainable development. [ABSTRACT FROM AUTHOR]

The valuation of ecosystem services is a powerful strategy on measuring the relations between natural resources and human capitals, to achieve the goal of protecting and promoting the positive contribution of nature. Gross Ecosystem Product (GEP) is a series of statistics that incorporates the monetary value of ecosystem services, which turns the ecological data comparable to GDP. As a case study of the relationship between ecosystem services and economic development, this work focused on the Inner Mongolia Autonomous Region (IMAR) in the northern part of China, with 12 main cities including 104 districts and counties in the highest latitude. The GEP was calculated at the municipal level using 30 m‐resolution remote sensing image data and a framework tailored to the specific economic and ecological conditions of IMAR. The results showed that the distribution of GEP in IMAR at the municipal level in 2020 ranged from 10.4 billion to 1920.7 billion RMB Yuan, with an overall value of 3.85 trillion RMB Yuan, and that the ratio of GEP to GDP was 1.17. Among various GEP components, the value of ecosystem regulating services took an essential part as 75.7%. Basically, the spatial distribution of GEP was diverse. The cities with the highest GEP values were Hulunbeir, Xilin Gol League, and Chifeng, The GEP hotspots are mainly distributed in the Hulunbuir region. Based on the dual analysis of GEP and GDP, there is still high room for improvement in most cities in the IMAR region. The GEP and GDP in IMAR can be enhanced through carbon trading, water rights and grassland tourism industry, which is conducive to the sustainable development of environment and economy in IMAR. [ABSTRACT FROM AUTHOR]

[Objective] The aims of this study are to investigate the spatial and temporal changes of runoff and sediment load in the Kuye River Basin, to quantify the contribution of climate change and human activities to variation of runoff and sediment load, and to provide scientific basis for the rational use of water resources and the optimal allocation of soil and water conservation measures in the Kuye River Basin. [Methods] Based on the runoff, sediment load and rainfall data of Xinmiao, Wangdaohengta, Shenmu and Wenjiachuan hydrological stations in Kuye River Basin from 1960 to 2020, the spatial and temporal variation characteristics of runoff and sediment load were analyzed by the linear trend method, Mann-Kendall trend test and Pettitt mutation test, and the double mass curve was used to quantitatively analyze the contribution rate of climate change and human activities to runoff and sediment load variation in different periods. [Results] Annual runoff and sediment load in the Kuye River Basin showed a significant decreasing trend from 1960 to 2020 (p<0.01). The runoff reduction rates of Xinmiao, Wangdaohengta, Shenmu and Wenjiachuan hydrological stations were 2.4 million m³/a, 3.4 million m³/a, 8.1 million m³/a, 10.6 million m³/a, the reduction rates of sediment load were 0.438 million t/a, 0.693 million t/a, 1.603 million t/a and 2.721 million t/a, respectively. The annual runoff and sediment load of each hydrological station changed abruptly both in 1979 and 1996, so the runoff and sediment load sequences could be divided into the reference period (1960-1979, P1) and the change period (1980-1996, P2;1997-2020, P3). During the study period, the average annual runoff depth and sediment load modulus of different sub-basins showed a decreasing trend, but there were differences in space. [Conclusion] The increasing human activities (water conservancy and soil conservation measures, coal mining, etc.) are the dominant factors on variation of runoff and sediment load in the Kuye River Basin. Compared with the base period, the runoff and sediment load of each hydrological station decreased in both P2 and P3 periods, and reduction was more intense in P3 period. In the P2 and P3 periods, the contribution of human activities to the reduction of runoff sediment transport was higher than that of rainfall changes. [ABSTRACT FROM AUTHOR]

Water conservation is an essential parameter for maintaining the ecological balance. The Three-River Source Region (TRSR) cannot be an exception, since it is one of the most influential water conservation reserves in the Qinghai–Tibet Plateau in China. Therefore, the realization of its scientific significance can determine its future regional sustainable development and the optimal allocation of water resources. The study of the past is critical to predict the future temporal and spatial changes in the water conservation of the TRSR. The first task of this study was to obtain the optimal runoff simulations in the TRSR from 1981 to 2014 by calibrating the adjustable the parameters of the Soil and Water Assessment Tool (SWAT) model. Then, the water conservation of the TRSR from 1981 to 2014 was quantified. Finally, the future water conservation of the TRSR was also predicted using the optimal SWAT model. The predication took into consideration the three terms including the near-term (2015–2044), mid-term (2045–2074), and long-term (2075–2099) in three different climate scenarios of SSP1-1.9 (SSP119), SSP2-4.5 (SSP245), and SSP5-8.5 (SSP585). The main findings are as follows: (1) both the coefficient of determination (R2) and Nash–Sutcliffe efficiency coefficient (NSE) for runoff simulation on the three sub-basins reached above 0.78 during the calibration and validation periods, which indicates the reasonableness of the SWAT model in the TRSR. (2) From 1981 to 2014, the water conservation capacity of the TRSR showed an increasing trend (0.5135 mm/year), and its changes had significant positive correlations with precipitation and temperature. The Yellow River Source (YR) and the Yangtze River Source (YZ) had the strongest and weakest water conservation capacities, respectively. (3) From 2015 to 2099, the water conservation in the TRSR in the SSP119, SSP245, and SSP585 scenarios decreased first and then increased, increased first and then decreased, and increased steadily, respectively. [ABSTRACT FROM AUTHOR]

Palestine is water-stressed and prone to possible shocks in water supply. However, about one-third to one-half of the delivered water in the Palestinian territories is lost in the distribution network, highlighting the necessity of a cost-effective supply policy that also minimizes corrosion and health-related risks by achieving a maximum level of water quality. There must be a decision-making system to help managers review and measure the status quo and develop optimal allocation decisions to resolve the potential problems with supply and quality as much as possible. This research presents optimal resource allocation for the drinking water supply system (DWSS) to minimize the unit cost of supply in the system and the chloride concentration of the water supplied simultaneously. A bespoke biobjective mixed-integer linear programming (BOMILP) model was developed. The weighted sum method (WSM) based on the positive ideal solution (PIS) approach is utilized to tackle the biobjectiveness of the model in a Pareto sense. The model was implemented and validated using a case study of Gaza. The results suggest that the share of desalinated water resources in the supply network will increase by about 50% in the 2030–2035 period. Furthermore, we found that the unit cost of supply is highly sensitive to a decrease in resource capacities. Finally, the average quality of water supplied can deteriorate rapidly if demand surges. The model can successfully handle the complexity of effective utilization of resources and yield optimal decisions for policymakers. [ABSTRACT FROM AUTHOR]

The Northwest Arid Region faces the most serious resource-based water shortage in China, with challenges from engineering-, structural- and management-based water shortages. This water scarcity critically limits the socio-economic development of the region. Rational allocation of scarce water resources to achieve sustainable development of the ecological environment and economy has become a key issue in water resources research in the Northwest Arid Region. South-Central Ningxia, part of the Northwest Arid Region, exemplifies these challenges. This paper examines the urban and rural water supply projects in South-Central Ningxia. The current scheduling scheme focuses primarily on the distribution of water demand, with inadequate attention paid to water-quality requirements. Localized exceedances of water-quality standards indicate the existing scheduling scheme has failed to effectively control water-quality issues while ensuring water quantity. This study is the first to systematically evaluate the impact of the South-Central Ningxia Water Supply Project on water quality alongside field surveys and data analysis and propose an optimized scheduling scheme that addresses both water quantity and quality needs. The main findings are as follows: 1. Overall water quality is good, except for consistently high total nitrogen levels. 2. The optimized scheme significantly reduced total nitrogen levels, achieving a maximum reduction rate of 78.81%, and met all Class III standards. [ABSTRACT FROM AUTHOR]

Water shortages are serious in northwest China due to the level of social and economic development, engineering, resource shortages, and other factors being restricted, so the conflict between supply and demand for water resources is prominent in different regions and different water use sectors. Therefore, Pingliang City was selected as the research object in this study. The membership function was introduced, and an interactive algorithm to correct model parameters based on the fairness constraint was derived. An uncertain multi-objective fuzzy programming model was also established. The results show that the optimal allocation of water will be 38,051.9~40,740 × 104 m3 and 39,938.4~41,317.5 × 104 m3 under a normal year (p = 50%) and a dry year (p = 75%) in 2025, respectively, and the corresponding water shortage rates will be 4.2% and 6.7%. In 2035, the optimal water allocation will be 45,644.1~49,245.9 × 104 m3 and 46,442.4~50,044.2 × 104 m3 and the water shortage rates will be 7.0% and 7.0%, respectively. The proportion of groundwater supply will decrease by 8.8% and 13.8% in 2025 and 2035 after the optimal allocation, the proportion of surface water supply will increase by 9.6% and 12.2%, and the proportion of reclaimed water will increase by −0.78% and 2.1%, respectively. The results can provide a technical reference for the development and utilization of water resources in other cities and similar areas in semi-arid regions. [ABSTRACT FROM AUTHOR]

Around the world, water rights systems govern the allocation of water to a multitude of users. Such systems primarily come into play during times of drought, when some users have to be shorted. Yet their management during times of excess can have implications for subsequent drought impacts. This is evident in the State of Colorado, where under "free river conditions" in which there is sufficient water to satisfy all water rights, anyone—including individuals lacking water rights—can divert as much as they want, unconstrained by the limit of their water right. Here, we estimate the amount of excess water used under such conditions within Division five of the Upper Colorado River Basin in the State of Colorado. Comparing the daily water withdrawals of diversion structures along the Colorado River and its tributaries with their (daily) water rights, we find that in 2017, 339 structures report days with excess withdrawals, amounting to 108 million cubic meters (87,577 acer feet). While such excess withdrawal is legal in Colorado, we argue that the free river condition is an antiquated rule that will make much needed reform of water allocation within the water‐stressed Colorado River Basin more difficult. We offer policy suggestions to address it. Plain Language Summary: Challenging water stress situations can be catalysts for reform. The Colorado River Basin is facing such a situation with ongoing drought since the turn of the Century. In the absence of much willingness for change, we propose a pragmatic step toward reform. Within the State of Colorado, when all water users have sufficient water to meet their decreed volumetric water right, the river is said to be in "free river conditions." Under these conditions, anyone—whether or not they own a water right—can divert as much water as they'd like until a senior user downstream makes a "call" on the river because they no longer have enough water to satisfy their right. We estimate that under free river conditions, excess water withdrawals of 108 million cubic meters (87,577 acer feet) is diverted beyond water users' decreed volumetric rights. We argue that such improperly defined water rights stand in the way of longer‐run reforms that seek to bring demand and supply in line in the Colorado River Basin, and propose alternative policies to bank this water to stave off future droughts. Key Points: We quantify the excess water diversions in the Upper Colorado Basin that go beyond diverters' water rightsThe Excess Diversions are a loophole in the Colorado Water System that will impede reformsStemming the Excess diversions will potentially help reduce economic and ecological stress of further depletion of Lake Powell [ABSTRACT FROM AUTHOR]

It is challenging for decision‐makers (DMs) to deal with uncertainties in multi‐level agricultural water resource systems, where DMs independently make decisions but have different levels of power. In this paper, we model the multi‐level agricultural water resources system under deep uncertainties as a Stackelberg game, use multi‐level programming to solve equilibrium water allocation problems, and introduce robustness metrics into multi‐level programming to balance solution feasibility and model optimality within uncertain environments. The approach is applied to a shallow groundwater area with three decision levels, pursuing, from the top level to the bottom one, high food production, fair water allocation, and increased economic benefit. The model generated a series of optimal equilibrium solutions with different robustness degrees. DMs can choose "rational" solutions according to their acceptable costs, oriented robustness degree, expected objective values, and advance risk assessment of uncertainties. Among these solutions, we capture a critical point with high objective values and strong robustness, where DMs can accomplish both objective optimality and solution robustness with a low cost. The proposed approach in this study provides a posterior decision support to consider solution robustness while designing policies in multi‐level agricultural water resource systems under deep uncertainties. Key Points: An introduction of robust measure into multi‐level programming balances solution robustness and model optimalityThere is a critical point that decision makers can achieve high objective values and strong robustness with low costs [ABSTRACT FROM AUTHOR]

Water-related conflicts in river catchments occur due to both internal and external pressures that affect catchment water availability. Lack of common understanding of human–water perspectives by catchment stakeholders increases the complexity of human–water issues at the river catchment scale. Among a range of participatory approaches, the development and use of serious games gained prominence as a tool to stimulate discussion and reflection among stakeholders about sustainable resource use and collective action. This study designed and implemented the ENGAGE (Exploring New Gaming Approach to Guide and Enlighten) game that mimics the dynamics observed during the dry season in the upper Ewaso Ngiro catchment, northwest of Mount Kenya. The purpose of this study was to explore the potential role of serious gaming in subsequent steps of strengthening stakeholder engagement (agenda setting, shared understanding, commitment to collective action, and means of implementation) toward addressing complex human–water challenges at the catchment scale. We assessed the type of decisions made during gameplay, the communication dynamics, the active participation, and the implication of decisions made on water availability. The results of three game sessions show that the ENGAGE game raised awareness and provided a recognizable hydrologic background to conflicts while guiding community discussions toward implementable decisions. The results revealed increasing active participation, knowledge gain, and use of plural pronouns and decreasing individual interests and conflicts among game participants. This study presents important implications for creating a collective basis for water management and can inform human–water policies and modification of the process behind water allocation rules in a river catchment. [ABSTRACT FROM AUTHOR]