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This article focuses on water security in Mykolaiv, a city of 0.5 million inhabitants in southern Ukraine, in the situation of scarcity of usable water resources caused by climate change and military operations. This problem arose after the Dnipro-Mykolaiv water pipeline was destroyed in April 2022 as a result of military operations and the supply of drinking water to the city was cut off. To ensure that the city's population has constant access to sufficient water of acceptable quality, a search for alternative water sources and a climate risk assessment were carried out for the new municipal water supply system from the Southern Bug River. The possible change in flow and its intra-annual distribution under the influence of climate change was modeled using the WaterGAP2 hydrological model and climate projections under the SSP1-2.6 and SSP5-P8.5 scenarios. It was found that under the SSP1-2.6 scenario, the reduction in river flow will be insignificant (up to a maximum of 14% in the far future) and there will be no restrictions on the city's water supply from this section of the river in the near (2021-2050) and far (2051-2080) period. The maximum water withdrawal for municipal water supply and the minimum environmental flow will reach their maximum value only in August (56% of the projected flow), which is not critical. Under the SSP5-8.5 scenario, in the long-term perspective of 2051-2080, the largest decrease in runoff will occur from May to October, and the water withdrawal will increase to 40-79% of the projected flow. The use of the research results not only in water management, but also in municipal administration, and their dissemination in territorial communities will contribute to the successful adaptation of socioeconomic and environmental processes in the region and can bring successful benefits not only to the economy, but also to communities. [ABSTRACT FROM AUTHOR]

Ensuring the protection of the aquatic environment and addressing the water scarcity and degradation of water quality in the Mediterranean region pose significant challenges. This study specifically aims to assess the impact of urban and industrial pollution on the ZAT River water quality. The study exploits a combination of field measurements and mathematical simulations using the PEGASE model. The objective is to evaluate how water quality changes throughout the different seasons and to determine whether olive oil factories discharge industrial wastewater into the river. The study reveals that the river water quality remains relatively stable along its course, up to km 64 in winter and km 71.77 in summer, where poor water quality is recorded. This degradation can be attributed to multiple factors. One of these factors is the discharge of industrial wastewater, which accounts for 47% of the COD pollution load. This industrial wastewater is released into the river without treatment during the production period (January–February) and inactivity period (March–May). The combined impact of urban and industrial wastewater is also associated with the decrease in water flow resulting from water withdrawals due to irrigation canals and groundwater recharge, which both contribute to the observed changes in river water quality. Importantly, field measurements combined with results obtained from the calibrated model provide compelling evidence of unauthorized wastewater discharges from the olive oil factories into the river. These results emphasize the need for stricter regulation, such as developing water quality monitoring strategies based on the use of modeling methodologies. They also emphasize the importance of improving wastewater management practices, such as setting up treatment plants for different sources of pollution or developing a co-treatment plant to mitigate the adverse impact of industrial pollution on river water quality. [ABSTRACT FROM AUTHOR]

Central Asia (CA) is a young integrated region formed after the collapse of the Soviet Union, with most of its infrastructure based on fossil fuels. The traditional energy and water infrastructure is facing huge inefficiency and technical losses. This study investigates the transition of the green, blue, and energy economies in Central Asia using a small-dimensional panel dataset on five countries, Uzbekistan, Kazakhstan, Kyrgyzstan, Tajikistan, and Turkmenistan, over the period 1995–2018. The authors analyze the impact of ecological footprint, water withdrawal, and energy consumption on gross domestic product. In applying the Panel Vector Error Correction Model, evidence was found supporting the long-running association between variables. Furthermore, the adjustment coefficients suggest that only GDP growth will adjust toward equilibrium. Overall, the findings suggest a more effective role of green transition compared to blue and energy transitions. [ABSTRACT FROM AUTHOR]

Carbon capture, utilization, and storage (CCUS) technologies are an integral part of the carbon-neutral technology portfolio at the present phase. However, large-scale implementation of CCUS technologies may increase urban water consumption and raise urban water security issues. In this paper, 596 large-scale coal-fired power plants were investigated in terms of water withdrawal and water consumption. To minimize total water withdrawal and total water consumption, a source-sink matching model for CCUS projects under water resource constraints was established to optimize the layout of CCUS projects in China. The results show that there is a mismatch between the distribution of coal-fired power plants in a spatial location and water resources. The annual increase in water withdrawal of about 27.6 billion tons and water consumption of about 2.4 billion tons is needed to achieve the 2 °C target, which will aggravate the water scarcity in the north-central cities. Implementation of CO2-enhanced water recovery (CO2-EWR) technology can offset some of the increase in urban water consumption owing to CCUS deployment. This study can provide data support for site selection in the large-scale deployment of CCUS technology and provide the theoretical basis for decision-makers to lay out CCUS projects. [ABSTRACT FROM AUTHOR]

Maize is vital in Ethiopia, particularly in Jimma. However, the benefits of deficit irrigation (DI) under varying nitrogen rates (NRs) for maize remain unknown. A 3-year field experiment assessed maize response to different NRs (N0=0 kg ha−1 , N23=23 kg ha−1 , N46=46 kg ha−1 , N69=69 kg ha−1 , and N92=92 N kg ha−1) under three DI levels (I50=50 , I75=75 , and I100=100% ETc). Factors such as rain-fed findings, soil testing, and local recommendations were considered in determining these rates. The results showed significant effects of DI, NR, and their interactions on grain yield, biomass, water-use efficiency (WUE), nitrogen-use efficiency (NUE), and harvest index (HI). Without nitrogen, 50% DI led to a greater than 50% reduction in yield and biomass compared with that at I100×N0. However, WUE and HI increased at I50×N92 compared with I100×N0. Increasing irrigation and nitrogen levels improved yield and biomass. Optimal WUE was achieved with irrigation close to 75% ETc without compromising yields. Agronomic yield significantly improved with NR above 92 kg N ha−1 under mild deficit and full irrigation, but higher rates did not provide additional benefits under severe deficit conditions. The economically optimum nitrogen rate ranged from 78 to 80 kg N ha−1 for irrigation levels ranging from 50% to 100% ETc. The study suggests that applying 80 kg N ha−1 with 75%–100% ETc levels is the best approach to enhance maize yield and achieve economic benefits. Further research is needed to explore DIs below 50% and above 100% ETc, as well as nitrogen fertilization rates above 92 kg ha−1 , in order to optimize maize production in the region. Practical Applications: This study examined the benefits of deficit irrigation and fluctuating nitrogen rates for maize production in Jimma, Ethiopia. By adopting deficit irrigation strategies and adjusting nitrogen rates, producers can reduce water withdrawal by approximately 25%. This approach optimizes both water-use efficiency and nitrogen-use efficiency without compromising yields. Increasing irrigation and nitrogen rates above I100×N92 improves agronomic yield, whereas reducing them below I50×N46 significantly decreases yield and WUE. Economically optimum nitrogen rates range from 78 to 80 kg N ha−1 with 50%–100% full irrigation. Balancing input costs and potential benefits is crucial for optimizing irrigation and nitrogen rates for maize production. To maximize agronomic yield, full irrigation with 92 kg N ha−1 (less than 96 kg N ha−1) is advisable. To optimize water use, 75% of full irrigation with 92 kg N ha−1 is recommended. To optimize nitrogen (economic yield) and achieve higher net returns, fully irrigating the maize crop with 80 kg ha−1 of nitrogen fertilization is advised. Farmers should adapt these findings to local conditions, considering factors such as soil characteristics, nitrogen price, and water price, and should consult local experts. Further research is needed to explore the effects of more or less than 50% full irrigation and of nitrogen doses exceeding 92 kg ha−1. [ABSTRACT FROM AUTHOR]

Lake Urmia in the northwest of Iran is one of the largest vanishing lakes in the world. Several water-saving strategies have been implemented in the lake basin over the last decade, but they are not producing efficient results. This study employed a modified version of the Soil and Water Assessment Tool (SWAT), an agrohydrological model, to investigate the basin-scale effectiveness of some water-saving plans implemented at the farm scale. Data collected from 301 monitoring sites in the Lake Urmia basin were applied to the modified SWAT model. The modified SWAT model was used to estimate water balance components and was coupled with the Water Accounting Plus framework (WA+). Six discharge stations, crop yields, evapotranspiration, and groundwater level tables were calibrated and validated from 1987 to 2015 within the Zarrineh Rud Basin (ZRB), the most crucial subbasin in the Lake Urmia basin. Next, four individual water-saving plans—changes in irrigation management and developments in irrigation systems, changes in fertilizer type and regime, changes in the type and method of cultivation, and farm size and shape adjustments—as well as seven combinations of the water-saving plans, were applied to the agrohydrological model. The results reveal that assessing restoration plans for Lake Urmia without considering both farm and basin scales provides no reliable results. With changes in management and the development of irrigation systems, considerable differences in water withdrawal were observed. Developing irrigation systems leads to enhanced water consumption and evapotranspiration, which is expected to improve water yield and crop productivity. However, individual plans such as developments in irrigation systems cannot increase the inflow to Urmia Lake, and combined water-saving strategies can help restore the lake only to a limited extent, because the changes in inflow are not substantial. [ABSTRACT FROM AUTHOR]

Global forest plantations are expanding, causing land-use changes and impacting the water cycle. This study assesses whether eucalyptus plantations reduce groundwater levels compared to grasslands in paired subtropical watersheds. The hydrological dynamics of surface and subsurface water were compared in three small watersheds in southern Brazil, mainly occupied by Eucalyptus saligna (Es-W, 79.9 ha), Eucalyptus benthamii (Eb-W, 82.1 ha), and degraded anthropized natural grassland (G-W, 109.4 ha). Rainfall, flow, and piezometric levels were monitored. Runoff, evapotranspiration, and water balance in the soil profile were estimated, and the subsurface environment was characterized using electrical resistivity tomography. During higher accumulated rainfall, water surplus increased for all watersheds. In the wet period (accumulated rainfall of 1098.0 mm), evapotranspiration was higher for eucalyptus (624.3 mm for Eb-W and 512.5 mm for Es-W) than for the grassland watershed (299.5 mm), resulting in the highest runoff in G-W (649.6 mm). During the dry period (accumulated rainfall of 478.5 mm), water deficit and withdrawal were mainly observed in forested watersheds, decreasing groundwater. Combining water balance and electrical resistivity tomography estimations results in a better understanding of the hydrological dynamics in paired watersheds with different land uses. This information is useful for developing best-practice management strategies for sustainable water resource use and forest production. [ABSTRACT FROM AUTHOR]

The knowledge of factors that influence the waters present in the hydrographic basins is extremely important for efficient management, considering its multiple uses. In this regard, the present work aims to apply mathematical modeling tools, expressed by the HRI-Hydro Tools, the hydrological model of large basins and WARM-GIS Tools, to carry out the physical characterization, hydrological modeling, and the quantitative water balance, for the Jaguarão River hydrographic basin (JRhb). In two scenarios, monthly-based, the reference flow adopted was Q90. Further the water stress index (WSI) was applied for each section of the JRhb drainage network, with emphasis on the analysis of the influence of multiple uses of water in the basin, especially for irrigation. The water withdrawal index (WWI) was used to develop a diagnosis of the watershed level of scarcity, taking into account the annual water commitment, to improve the quantitative representation of water for the JRhb. The results of the hydrological modeling performed showed that, in general, the model presented a good performance both in the calibration and in the validation of the studied periods. The WSI representation showed that in the current scenario (realistic scenario) the basin has been suffering great water stress in the months that comprise the summer season (December, January, February, and March). In addition, the application of the WSI exposed the great influence of water use in the production of irrigated rice in this territory. This result was supported by WWI, which revealed sub-basins that were in a vulnerable state, requiring intensive management and major mitigation efforts. [ABSTRACT FROM AUTHOR]

Real water saving is a important concept in water resources management, which can express previous failures in reducing agricultural water consumption, despite increasing irrigation efficiency. In the present research, while calculating the water requirement for the cultivation of the cropping pattern document in Khuzestan province of Iran and harvesting the intended yield, the crop substitution and changing the planting date method (in four scenarios) has been considered as a sustainable solution to reduce the actual agricultural water consumption. Scenarios 1 to 4, respectively, included replacing part of the cultivated area of sugarcane, fodder corn, and rice with sugar beet, fodder sorghum, and sesame, in 3 consecutive years, and changing the planting date of watermelon and tomato from summer to winter in 1 year. For this purpose, the actual evapotranspiration was determined using FAO-56 Penman–Monteith equations and the expected crop yield at the county scale. Then, using the history of cultivation of different crops in each county and the subwatershed map of the Khuzestan province, the actual evapotranspiration, net irrigation requirement, and water withdrawal from rivers in each subwatershed of Khuzestan province were determined. Results showed that implementation of scenarios 1, 2, 3, and 4 can reduce 551, 25, 194, and 79 hm3 of actual water consumption and decreases 2,160, 104, 775, and 303 hm3 of water withdrawal, respectively. If all the scenarios are implemented together, it can be expected that the reduction in actual agricultural water consumption and its water withdrawal will be equivalent to 5% and 20% of the rivers discharge in Khuzestan province, with a probability of 80%. By considering the real water saving, economic, and social criteria, it can be concluded that replacing sugarcane with sugar beet is the first priority of implementation, whereas changing rice with sesame is the last priority of implementation. Practical Applications: Water reduction consumption is one the most challenging issues in agricultural water management. We know that agriculture consumes mostly fresh water to produce all kinds of agricultural products. The water is converted from liquid to vapor and removed from the target catchment area by atmospheric currents. Therefore, one of the most useful ways to reduce actual water consumption in agriculture is to improve the cropping pattern. Modifying the cropping pattern can challenge the indigenous knowledge of farmers and affect their habits as well as reduce the income of local communities in some cases. Therefore, it is important to pay attention to the profit of the replaced crop and the level of familiarity of the farmer with how to cultivate it in determining the cropping pattern. This research examines the modification of the cropping pattern in Khuzestan province of Iran, which includes replacement of sugarcane, fodder corn, and rice with sugar beet, sorghum, and sesame, respectively, to reduce agricultural water consumption. For this purpose, the reduction of water consumption, reduction of farmer's income, and social tendencies have been seen in the defined scenarios. [ABSTRACT FROM AUTHOR]

Groundwater numerical modeling is a crucial scientific tool for understanding groundwater circulation and supporting regional water resource planning and management. The effectiveness of these models depends largely on the accuracy of hydrogeological parameters within aquifers, which are often spatially heterogeneous and randomly distributed due to complex geological and tectonic factors. Traditional modeling approaches frequently overlook this randomness, compromising the precision and resolution of groundwater simulations. This study focuses on a section of the Qingshui River in the Huaihe River Basin. Using field and laboratory data, probability distribution functions for key parameters like hydraulic conductivity, specific yield, and specific storage were developed. These functions were integrated into the groundwater model to reflect the inherent stochastic nature of aquifer properties. This integration significantly enhanced model accuracy, reducing the root mean square error of simulated water levels from 0.47-1.43 m to 0.13-0.16 m and improving the Nash-Sutcliffe efficiency coefficients (NSE) from -2.96-0.73 to 0.94-0.98. Additionally, the model facilitated analysis of the interactions between river and groundwater, particularly in the hyporheic zone, under various scenarios. It identified spatial and temporal variations in groundwater recharge dynamics and delay effects at different distances from the river channel. For instance, recharge rates at 50 m and 150 m from the river were 0.295 m/day and 0.015 m/day, respectively, indicating stronger recharge closer to the river. The study also assessed the impact of varying river flows, riverbed permeability, and irrigation practices on water exchanges between the river and groundwater. These factors were found to significantly influence the intensity of water exchange, seepage, and groundwater reserves. This research provides valuable insights for managing river-groundwater interactions and analyzing the ecological environment of surrounding groundwater systems, underscoring the importance of incorporating stochastic characteristics into groundwater modeling. [ABSTRACT FROM AUTHOR]

Efforts to predict long‐term changes in continental runoff at both global and basin scales generally remain ambiguous. Here we use a global runoff reconstruction and a Bayesian statistical method to narrow uncertainties in runoff projections from the latest generation of global climate models. Three representative tropical river basins are used to illustrate the application and showcase the potential for substantial reduction in modeling uncertainty. Yet, results are fairly sensitive to the selected reconstruction thus highlighting the need for reliable and homogeneized gridded runoff data sets or river discharge measurements. Moreover, climate models do not account for water withdrawals, whose effect on observed runoff should also be removed in order to detect and attribute the hydrological effect of climate change. Finally, and more importantly, most models fail at capturing the observed recent decrease in runoff ratio, which may highlight either model deficiencies or increasing water derivation over the selected river basins. Plain Language Summary: The response of river discharge under the effect of climate change generally remains very uncertain. Bayesian statistical tools and global runoff reconstructions, constrained by flow observations, can nevertheless be used to evaluate the capacity of climate models to simulate the historical runoff and, thus, constrain its future changes at the basin scale. Three representative tropical river basins help illustrate the method. The results are nevertheless sensitive to the choice of the runoff reconstruction, thus emphasizing the need to have good quality flow data, if possible corrected for the direct effects of water withdrawals from the rivers or the aquifers which supply them. Worryingly, the latest generation of global climate models show a systematic underestimation of the downward evolution of the ratio between runoff and precipitation, which could reflect the increasing importance of these withdrawals or the inability of models to capture the rapidly increasing land surface evapotranspiration under climate change. Key Points: Global 21st century projections of basin‐scale runoff remain highly model‐dependent within the latest generation of Earth System ModelsGridded runoff reconstructions and precipitation observations can however be used to constrain the projections through Bayesian statisticsA model‐observation mismatch is underlined regarding recent changes in the annual runoff to precipitation ratio over specific river basins [ABSTRACT FROM AUTHOR]

Agriculture water use accounts for 70% of the total water withdrawal worldwide. The evapotranspiration during crop growth is one of the important hydrological processes in the agricultural water cycle. This study proposed the concept of artificial irrigation evapotranspiration of irrigated crops to describe that the evapotranspiration caused by irrigation water use. Irrigated crops rely on two kinds of water sources: precipitation and irrigation water. With the construction of irrigation schemes, the artificial irrigation evapotranspiration plays an increasingly important role in the dualistic water cycle system of irrigated cropland. To reveal the amount of artificial irrigation evapotranspiration of 17 categories of irrigated crops in China, this study proposed a new quantitative model system which was established based on traditional evapotranspiration models and soil water balance models. Based on the new model system, we calculated the annual artificial irrigation evapotranspiration of irrigated crops for the period 2013 to 2017 in China. The results showed that the proportion of artificial irrigation evapotranspiration to the total evapotranspiration of irrigated crops was 41.3%, whose value was 228.1 km3 a−1. The artificial irrigation evapotranspiration in different agricultural water management regions were 90.0 km3 a−1 in the northeast region, 86.0 km3 a−1 in the southeast region, and relatively low 52.2 km3a−1 in the west region. The results of this study can provide methods for water management and policy–making in agricultural irrigated areas, and it can also provide a preliminary understanding of the influence of human activities on the dualistic water cycle in cropland. [ABSTRACT FROM AUTHOR]

Drought is a major factor affecting crops, thus efforts are needed to increase plant resilience to this abiotic stress. The overlapping signaling pathways between drought and cell wall integrity maintenance responses create a possibility of increasing drought resistance by modifying cell walls. Here, using herbaceous and woody plant model species, Arabidopsis and hybrid aspen, respectively, we investigated how the integrity of xylan in secondary walls affects the responses of plants to drought stress. Plants, in which secondary wall xylan integrity was reduced by expressing fungal GH10 and GH11 xylanases or by affecting genes involved in xylan backbone biosynthesis, were subjected to controlled drought while their physiological responses were continuously monitored by RGB, fluorescence, and/or hyperspectral cameras. For Arabidopsis, this was supplemented with survival test after complete water withdrawal and analyses of stomatal function and stem conductivity. All Arabidopsis xylan-impaired lines showed better survival upon complete watering withdrawal, increased stomatal density and delayed growth inhibition by moderate drought, indicating increased resilience to moderate drought associated with modified xylan integrity. Subtle differences were recorded between xylan biosynthesis mutants (irx9, irx10 and irx14) and xylanaseexpressing lines. irx14 was the most drought resistant genotype, and the only genotype with increased lignin content and unaltered xylem conductivity despite its irx phenotype. Rosette growth was more affected by drought in GH11- than in GH10-expressing plants. In aspen, mild downregulation of GT43B and C genes did not affect drought responses and the transgenic plants grew better than the wild-type in drought and well-watered conditions. Both GH10 and GH11 xylanases strongly inhibited stem elongation and root growth in well-watered conditions but growth was less inhibited by drought in GH11-expressing plants than in wild-type. Overall, plants with xylan integrity impairment in secondary walls were less affected than wild-type by moderately reduced water availability but their responses also varied among genotypes and species. Thus, modifying the secondary cell wall integrity can be considered as a potential strategy for developing crops better suited to withstand water scarcity, but more research is needed to address the underlying molecular causes of this variability. [ABSTRACT FROM AUTHOR]

This paper examines the prospects for developing and implementing a binational water management agreement for the transboundary Santa Cruz River that crosses the US–Mexico boundary near the sister cities of Nogales, Sonora–Nogales, Arizona. After considering the geography, history, socio-economic context, and binational agreements affecting utilization of the Santa Cruz River, we review the conditions influencing recent binational progress on another transboundary river, the Tijuana River. Specifically, we ask what conditions created a favorable environment in which a binational agreement for management of the Tijuana River Watershed (TRW) was developed, what specific actions by relevant policy officials took place, and how the final agreement was reached. We then compare the dynamics that unfolded in the TRW with conditions in the Santa Cruz River to identify obstacles hindering progress towards achieving an International Boundary and Water Commission (IBWC) agreement (Minute) on shared management of the Santa Cruz River in its international reach. We find that the required political conditions that favored an agreement on the Tijuana River are not yet met on the Santa Cruz, although several favorable conditions do exist. We conclude with an assessment of current prospects for advancing binational cooperation that can inform discussion of how an IBWC Minute could be drafted to address water resource management issues in the Santa Cruz River Basin. [ABSTRACT FROM AUTHOR]

Estimation of human water withdrawals is more important now than ever due to uncertain water supplies, population growth, and climate change. Fourteen percent of the total water withdrawal in the United States is used for public supply, typically including deliveries to domestic, commercial, and occasionally including industrial, irrigation, and thermoelectric water withdrawal. Stewards of water resources in the USA require estimates of water withdrawals to manage and plan for future demands and sustainable water supplies. This study compiled the most comprehensive conterminous United States water withdrawal data set to date and developed a machine learning framework for estimating public supply withdrawals and associated uncertainty for the period 2000–2020. The modeling approach provides service area resolution estimates to allow for annual and monthly water withdrawal estimation while incorporating a complex array of driving factors that include hydroclimatic, demographic, socioeconomic, geographic, and land use factors. Model results reveal highly variable and lognormally distributed per‐capita water withdrawal, spanning from 30 to 650 gallons per capita per day (GPCD), across community, regional, and national scales, with pronounced seasonal variations. Analysis of estimated withdrawal trends indicates that the national annual average withdrawal experienced a decline at a rate of 0.58 GPCD/year during the period from 2000 to 2020. Model interpretation reveals a complex interplay between public supply withdrawal and key predictors, including population size, warm‐season precipitation, counts of large buildings and houses, and areas of urban and commercial land use. The developed models can forecast future public supply driven by various climate, demographic, and socioeconomic scenarios. Key Points: Consistent, reproducible estimates of monthly water withdrawals were generated at the spatial resolution of USA water service areasSpatial and temporal variability of public supply withdrawal is driven by a complex array of explanatory featuresAn operational machine learning framework was developed to estimate water withdrawals, prediction uncertainty, and feature importance [ABSTRACT FROM AUTHOR]

Swimming venues provide various services based on water as the carrier, but studies on their water use are few. This study constructed a stochastic model to quantify the water use efficiency of indoor swimming venues under different scenarios based on Monte Carlo simulation. It explored the impact of shower behavior, swimming pool replenishment rate, and appliance water efficiency on water use efficiency in swimming venues. The results show that the indoor swimming pool replenishment volume and shower water use accounted for relatively high proportions and are relatively stable, with a total of about 81 % of the total water use; the model could effectively quantify the water demand in swimming pools under different scenarios. The theoretical water withdrawal of the swimming pool per unit volume under the saving mode and the reasonable mode are 26.32 m3 /(m3 ·a) and 34.71 m3 /(m3 ·a) respectively, which are comparable to the water use quota values of swimming venues by region in China. Conclusions could be drawn from sensitivity analysis that replenishment rate is the most important factor affecting the water withdrawal per unit volume of the swimming pool, followed by shower duration. This study provides theoretical basis for water-saving management to swimming venue managers, and reference for different industries to carry out research on the mechanism of water use behavior and water demand analysis. [ABSTRACT FROM AUTHOR]

There is a growing concern about limited water supply and water scarcity in many river basins across the world. The agricultural sector is the largest user of freshwater on the planet, with a growing amount of water extracted for livestock systems. Here, we use data from the GLEAM model to advance previous studies that estimated livestock water footprints by quantifying water use for feed production, animal drinking water, and animal service water. We additionally account for the role of trade in accounting for feed water allocations to different animals in different countries and make use of a hydrologic model to estimate feed irrigation water requirements for individual crops at a high spatial resolution. Lastly, we estimate the contribution of livestock water abstractions to water stress at a small river basin scale for the entire globe. We find that feed production water accounts for the majority (>90%) of global livestock water withdrawals, though there is regional variation. Similarly, we find large regional variation in the water consumption per head by livestock species. Despite consuming >200 km3 of water per year, we find that reducing water use in the livestock system alone will rarely reduce water stress in high-stress basins. This study highlights the need for quantifying locally relevant water use and water stress metrics for individual livestock systems. [ABSTRACT FROM AUTHOR]

The flow in the draft tube of the water turbine is affected by the upstream flow and the inherent structure accompanied by various undesirable characteristics, affecting the efficient and stable operation of the water turbine. Changing the flow structure downstream of the runner is an important measure to reduce hydraulic loss in the draft tube and improve stability. In this study, three downstream structures of the runner, namely, the non-locking nut, small locking nut, and extended locking nut are numerically calculated and verified using experimental results. The unstable flow characteristics of the draft tube are analyzed using variations in swirling flow, backflow, pressure gradient, and vortex strip. The results show the non-negligible effect of the locking nut, which significantly reduces the rotational momentum flux at the draft tube inlet, accelerates the decay rate of the swirling flow, and suppresses the generation of axial low pressure. The small locking nut significantly reduces the pressure gradient, shortens the backflow zone, and decreases the backflow velocity. The extended locking nut reduces the backflow zone in some sections and reduces the vortex zone of the straight section but prolongs the backflow zone and increases the backflow velocity. [ABSTRACT FROM AUTHOR]

Ensuring the sustainable management of water and sanitation for all is the primary goal of Sustainable Development Goal 6 (SDG 6). SDG indicator 6.4.2 (level of water stress) is critical for monitoring the progress toward SDG 6. The assessment of the SDG indicator 6.4.2 is currently based on statistical data at the national scale, i.e., one value for one country, which cannot reflect spatial variability in water stress in a country. The lack of data at sub-national scales limits the assessment of water stress in sub-national regions. This study developed a method of disaggregating national statistical renewable water resources (TRWR) and freshwater withdrawals (TFWW) to estimate the SDG 6.4.2 water stress indicator at a sub-national scale by combining satellite remote sensing data and model simulated data. Remote sensing (RS)-based precipitation (P); the difference between precipitation and evapotranspiration (P-ET); and the difference between precipitation, evapotranspiration, terrestrial water storage change (P-ET-dS), and model-simulated naturized runoff and withdrawal water use were used as spatial and temporal surrogates to disaggregate the national-scale statistics of TRWR and TFWW to the grid scale. Gridded TRWR and TFWW can be used to calculate the water stress of any interest regions. Disaggregated TRWR, TFWW, and water stress estimation were validated at three different spatial scales, from major river basins and provinces to prefectures in China, by comparing the corresponding statistical data. The results show that the disaggregation for TRWR is generally better than for TFWW, and the overall accuracy for water stress estimation can reach up to 91%. The temporal evolution of disaggregated variables also showed good consistency with statistical time series data. The RS-based P-ET and P-ET-dS have great potential for disaggregating TRWR at different spatiotemporal scales, with no obvious differences with the results using the model simulation as a surrogate for the disaggregation of SDG indicator 6.4.2. The disaggregation accuracy can be further improved when the sub-regional statistical data of TRWR and TFWW are applied to the disaggregation approach. [ABSTRACT FROM AUTHOR]

In the context of China's freshwater crisis high-resolution data are critical for sustainable water management and economic growth. Yet there is a dearth of data on water withdrawal and scarcity regardless of whether total or subsector amount, for prefectural cities. In administrative and territorial scope, we accounted for water withdrawal of all 63 economic-socio-environmental sectors for all 343 prefectural cities in China, based on a general framework and 2015 data. Spatial and economic-sector resolution is improved compared with previous studies by partitioning general sectors into industrial and agricultural sub-sectors. Construction of these datasets was based on selection of 16 driving forces. We connected a size indicator with corresponding water-withdrawal efficiency. We further accounted for total blue-water withdrawal and quantitative water scarcity status. Then we compared different scopes and methods of official accounts and statistics from various water datasets. These disaggregated and complete data could be used in input-output models for municipal design and governmental planning to help gain in-depth insights into subsector water-saving priorities from local economic activities. [ABSTRACT FROM AUTHOR]

We provide a dataset of irrigation water withdrawals by crop, county, year, and water source within the United States. We employ a framework we previously developed to establish a companion dataset to our original estimates. The main difference is that we now use the U.S. Geological Survey (USGS) variable 'irrigation — total' to partition PCR-GLOBWB 2 hydrology model estimates, instead of 'irrigation — crop' as used in previous estimates. Our findings for Surface Water Withdrawals (SWW), total Groundwater Withdrawals (GWW), and nonrenewable Groundwater Depletion (GWD) are similar to those of prior estimates but now have better spatial coverage, since several states are missing from the USGS 'irrigation — crop' variable that was originally used. Irrigation water use increases in this study, since more states are included and 'irrigation — total' includes more categories of irrigation than 'irrigation — crop'. Notably, irrigation in the Mississippi Embayment Aquifer is now captured for rice and soy. We provide nearly 2.5 million data points with this paper (3,142 counties; 13 years; 3 water sources; and 20 crops). [ABSTRACT FROM AUTHOR]

Conjunctive use management of water resources is of paramount importance in the backdrop of the growing demand for freshwater resources. With this viewpoint, this study is aimed to present a methodological approach utilizing the combined use of simulation and optimization models for evolving strategies or policies for the management of water resources in a well-field connected to a stream. The proposed methodology incorporates the coupling of the groundwater simulation model with the optimization model for decision-making through the response matrix method. In this study, a numerical groundwater flow model using MODFLOW was used to simulate the response of stream-aquifer interactions. A linear optimization model was formulated to account for the best optimal groundwater withdrawal taking into consideration the allowable drawdown, permissible stream flow depletion, and satisfaction of the water demands. Such management options permit the investigation of alternative strategies for groundwater abstraction in a well-field hydraulically connected to a stream for sustainable development of water resources. The model was applied in a hypothetical well field study area hydraulically connected to a stream and satisfactory results were obtained. The methodology was also very important to understand the tradeoff between groundwater withdrawal and the depletion of flow to the nearby stream. This approach was applied to the Aynalem well field stream-aquifer system which is located in Northern Ethiopia. Results show that groundwater extraction from the Aynalem well field triggers stream flow depletion and it is possible to decrease the stream flow depletion by 3.5–4.5% by adjusting current groundwater withdrawal schedules and configuration of existing wells. [ABSTRACT FROM AUTHOR]

The consistently low yield turnout of maize on farmers' fields owing to drought and the nutritional challenges attributable to the consumption of white endosperm maize pose a major threat to food and nutritional security in Sub-Saharan Africa (SSA). The objectives of this study were to assess the performance of newly developed extra-early maturing orange hybrids under managed drought and well-watered conditions, compare the outcomes of multiple-trait base index and multi-trait genotype–ideotype distance index selection procedures, and identify drought-tolerant hybrids with stable performance across contrasting environments for commercialization in SSA. One hundred and ninety orange hybrids and six checks were evaluated under managed drought and well-watered conditions at Ikenne for two seasons between 2021 and 2023. A 14 × 14-lattice design was used for the field evaluations under both research conditions. Drought stress was achieved by the complete withdrawal of irrigation water 25 days after planting. Results revealed significant differences among the hybrids under drought and well-watered conditions. Grain yield, ears per plant, and plant aspect under managed drought were correlated to the same traits under well-watered conditions, suggesting that the expression of these traits is governed by common genetic factors. Twenty-nine hybrids were identified as top-performing drought-tolerant hybrids by the multiple-trait base index and the multi-trait genotype–ideotype distance index. Of the selected outstanding 29 hybrids, 34% were derived from crosses involving the tester TZEEIOR 197, demonstrating the outstanding genetic potential of this inbred line. Further analysis of the 29 selected hybrids revealed TZEEIOR 509 × TZEEIOR 197 as the hybrid that combined the most drought-tolerant adaptive traits. However, the hybrids TZEEIOR 526 × TZEEIOR 97, TZEEIOR 384 × TZEEIOR 30, TZEEIOR 515 × TZEEIOR 249, TZEEIOR 510 × TZEEIOR 197, TZEEIOR 479 × TZEEIOR 197, and TZEEIOR 458 × TZEEIOR 197 were identified as the most stable hybrids across drought and well-watered conditions. These hybrids should be extensively tested in multi-location trials for deployment and commercialization in SSA. [ABSTRACT FROM AUTHOR]

Electricity distribution has become one of the most essential components of our society since the beginning of human civilization, relying on an abundant, reliable, and affordable power supply. Fossil fuels dominate the production of electricity (89.57 %), emitting 68.7 % of greenhouse gases, polluting water and soil, and depleting fossil fuels. Future energy needs are faced with growing demand for coal (772 million tonnes by 2040) and fluctuating fuel prices. The Indian power sector withdraws over 20 billion m³ of water, whereby coal power plants use around 35 % of freshwater. Among the seventeen sustainable development goals, Goal 7 emphasizes meeting the demand for electricity, the availability of clean fuels, and mitigating air pollution. In 2021, about 747 TWh of energy consumption was met by coal, oil (92 TWh), and solar energy (25 TWh). Renewable power would meet the world’s growing energy needs, reduce greenhouse gas emissions, boost the economy, and strengthen the society. Therefore, renewable energy has gained global attention as a sustainable electricity source. For this, a thorough examination of the economic and social implications of electricity generation technologies must be carried out. This study discusses how fossil fuel-based electricity generation affects global health and the environment and helps achieve Goal 7 of the sustainable development goals. All sectors must work together to stop global warming and water war and make electricity available worldwide for integrated development. [ABSTRACT FROM AUTHOR]

Water scarcity is a pressing global issue driven by increasing water demands and changing climate conditions. Based on novel estimates of water availability and water use in Chile, we examine the challenges and risks associated with groundwater (GW) withdrawals in the country's central-north region (27–35° S), where extreme water stress conditions prevail. As total water use within a basin approaches the renewable freshwater resources, the dependence on GW reserves intensifies in unsustainable ways. This overuse has consequences that extend beyond mere resource depletion, manifesting into environmental degradation, societal conflict, and economic costs. We argue that the "Day Zero" scenario, often concealed by the uncertain attributes of GW resources, calls for a reconsideration of water allocation rules and a broader recognition of the long-term implications of unsustainable GW use. Our results offer insights for regions worldwide facing similar water scarcity challenges and emphasize the importance of proactive and sustainable water management strategies. [ABSTRACT FROM AUTHOR]

To achieve sustainable development goals in Huangshui River Basin (HRB), strengthening adaptive water resources management under the dual impact of climate change (CC) and human interventions (HI) is of great significance. Multiple mathematical and statistical methods were employed to determine the runoff trend and breakpoint in HRB. The elasticity of CC and HI on the runoff decline and their contributions were quantitatively discerned based on the Budyko hypothesis, complementary method, and SWAT hydrological model. The results show that (1) the runoff showed a decreasing trend, with a runoff breakpoint in 1990; (2) the elasticity coefficients indicated a 1% increase in P, ET0, and n, leading to a 2.19% increase, a 1.19% decrease, and a 1.52% decrease in the runoff, respectively; (3) the Budyko framework determined the contribution of CC and HI to runoff decline in HRB to be 37.98-41.86% and 58.14-62.02%, respectively, and that estimated by SWAT hydrological model to be 38.72 and 61.28%, respectively; (4) HI were the primary factor for runoff decline in HRB, where direct anthropogenic disturbances such as water withdrawals and water conservancy project construction were the main drivers. The findings have important scientific significance for water resources planning and management in HRB. [ABSTRACT FROM AUTHOR]

Irrigation activities are important for sustaining food production and account for 70 % of total global water withdrawals. In addition, due to increased evapotranspiration (ET) and changes in the leaf area index (LAI), these activities have an impact on hydrology and climate. In this paper, we present a new irrigation scheme within the land surface model ORCHIDEE (ORganising Carbon and Hydrology in Dynamic EcosystEms)). It restrains actual irrigation according to available freshwater by including a simple environmental limit and using allocation rules that depend on local infrastructure. We perform a simple sensitivity analysis and parameter tuning to set the parameter values and match the observed irrigation amounts against reported values, assuming uniform parameter values over land. Our scheme matches irrigation withdrawals amounts at global scale, but we identify some areas in India, China, and the USA (some of the most intensively irrigated regions worldwide), where irrigation is underestimated. In all irrigated areas, the scheme reduces the negative bias of ET. It also exacerbates the positive bias of the leaf area index (LAI), except for the very intensively irrigated areas, where irrigation reduces a negative LAI bias. The increase in the ET decreases river discharge values, in some cases significantly, although this does not necessarily lead to a better representation of discharge dynamics. Irrigation, however, does not have a large impact on the simulated total water storage anomalies (TWSAs) and its trends. This may be partly explained by the absence of nonrenewable groundwater use, and its inclusion could increase irrigation estimates in arid and semiarid regions by increasing the supply. Correlation of irrigation biases with landscape descriptors suggests that the inclusion of irrigated rice and dam management could improve the irrigation estimates as well. Regardless of this complexity, our results show that the new irrigation scheme helps simulate acceptable land surface conditions and fluxes in irrigated areas, which is important to explore the joint evolution of climate, water resources, and irrigation activities. [ABSTRACT FROM AUTHOR]

The aquifers of the Togolese coastal sedimentary basin are the principal sources of water for almost half of the country's population. These aquifers' features have not been adequately monitored and studied. The resource is threatened by human activities, notably agriculture, industry, and withdrawals for drinking water supplies. This situation is exacerbated by the potential effects of climate change. For this research, a basin-scale study was conducted to estimate current groundwater recharge and its future evolution in response to climate change. A recharge model based on Thornthwaite–Mather balance equations using runoff coefficients characterizing land use was fed with current and future climate data from an optimistic scenario (RCP 4.5) and a pessimistic scenario (RCP 8.4). Despite the associated uncertainties, the soil–water balance model at monthly time steps predicts a recharge of 3 to 455 mm per year from 2020 to 2039, and 40 to 420 mm per year from 2040 to 2059 under the optimistic RCP 4.5 scenario. According to the pessimistic RCP 8.5 scenario, the recharge will range between 16 and 515 mm per year from 2020 to 2049 and from 1 to 467 mm per year between 2040 and 2059. As a result, the basin's groundwater recharge range, which is currently 47 to 225 mm, will significantly increase. This study provides a scientific basis for the sustainable management of groundwater in the Togolese coastal sedimentary basin. The recharge of the groundwater in the basin will increase regardless of the climate scenario and will support future development in the Togolese coastal sedimentary basin. [ABSTRACT FROM AUTHOR]

Draft tube vortex rope is considered a special cavitation flow phenomenon in tubular turbine units. Cavitation vortex rope is one of the most detrimental factors affecting the safety of hydraulic turbines. In this study, ANSYS CFX software was utilized to numerically simulate the internal cavitation flow of a hydraulic turbine draft tube. The evolution of the cavitation vortex core was characterized by vortex line distribution and vorticity transport equation. The shape and number of blades influenced the revolving direction and distribution characteristics of the vortex close to the runner cone, which formed a counterclockwise-clockwise-counterclockwise distribution pattern. Simultaneously, there were many secondary flows in the draft tube. Mutual cancellation and dissipation between the flows was one of the reasons for reduction in vorticity. When the cross-sectional shape of the draft tube was changed, the vorticity was distributed from the center of the vortex rope to all parts of the cross-sectional draft tube, with extreme values at the center and at the walls. The vortex stretching and dilatation terms played a major role in the change in vorticity, with the baroclinic torque having an effect at the center of the vortex rope, this study is helpful to understand the flow of water in the draft tube and guide the design and optimization of the draft tube in engineering application [ABSTRACT FROM AUTHOR]

Accurate maps of irrigation extent and dynamics are important to study food security and its far-reaching impacts on Earth systems and the environment. While several efforts have been made to map irrigated areas in China, few of them have provided multi-year maps, incorporated national land surveys, addressed data discrepancies, and considered the fraction coverage of irrigated cropland (i.e., the mixed pixel issue). In this study, we addressed these important gaps and developed new annual maps of China’s irrigated cropland from 2000 to 2020, named as CIrrMap250. We harmonized irrigated area statistics and land surveys and reconciled them with remote sensing data. The refined estimates of irrigated area were then integrated with multiple remote sensing data (i.e., vegetation indices, hybrid cropland product, and paddy field maps) and irrigation suitability map through a semi-automatic training approach. We then evaluated our CIrrMap250 maps using independently interpreted 20,000 reference locations, high-resolution irrigation water withdrawal data, and existing local to nationwide maps. Our evaluation results showed that CIrrMap250 agreed well with the reference points, with an overall accuracy of 0.79–0.88 for years 2000, 2010, and 2020, respectively. The CIrrMap250-estimated irrigated area can explain 50–60 % of the variance in irrigation water withdrawals across China. Our CIrrMap250 product showed superior performance than currently available ones (i.e., IrriMap_CN, IAAA, and GFSAD). CIrrMap250 revealed that China’s irrigated area has increased by about 180,000 km2 (or 25 %) from 2000 to 2020, with the majority (61 %) being water-unsustainable and occurring in regions facing high to severe water stress. Moreover, our product unveiled a noticeable northward shift of China’s irrigated area, attributed to substantial expansion in irrigated cropland across Northeast and Northwest China. The accurate representation irrigation area in CIrrMap250 will greatly support hydrologic, agricultural, and climate studies in China for improved water and land resources management. [ABSTRACT FROM AUTHOR]

Tourism on Gili Air, a small coral island in Indonesia, has increased significantly. Groundwater is the primary water source on the island. This study aims to estimate the sustainability of groundwater use on this small coral island. It conducts an initial assessment of the freshwater lens system using cost-effective methods to evaluate the available freshwater volume and sustainability of water withdrawals related to tourism. The results and methods can be transferred to other low-lying islands. The results show that Gili Air has a well-developed freshwater lens, estimated to contain 2 million cubic meters of water, with an annual recharge rate four times higher than the water demand of the island's inhabitants. However, our findings suggest that the rapid increase in tourism resulted in unsustainable water withdrawals between 2016 and 2019. Without proper groundwater monitoring and management, this could lead to seawater intrusion into the aquifer. [ABSTRACT FROM AUTHOR]

The Aswan cliff on Comet 67P/Churyumov–Gerasimenko collapsed on 2015 July 10. Thereby, relatively pristine comet material from a depth of |$\sim 12\, \mathrm{m}$| was exposed at the surface. Observations of the collapse site by the microwave instrument Rosetta /Microwave Instrument for Rosetta Orbiter (MIRO) have been retrieved from 8 months prior to collapse, as well as from 5, 7, and 11 months post-collapse. The MIRO data are analysed with thermophysical and radiative transfer models. The pre-collapse observations are consistent with a 30 MKS thermal inertia dust mantle with a thickness of at least |$3\, \mathrm{cm}$|⁠. The post-collapse data are consistent with (1) a dust/water–ice mass ratio of 0.9 ± 0.5 and a molar CO2 abundance of ∼30 per cent relative to water; (2) formation of a dust mantle after ∼7 months, having a thickness of a few millimetres or a fraction thereof; (3) a CO2 ice sublimation front at 0.4 cm that withdrew to 2.0 cm and later to |$20\pm 6\, \mathrm{cm}$|⁠ ; (4) a thermal inertia ranging 10–45 MKS; (5) a gas diffusivity that decreased from |$0.1$| to |$0.001\, \mathrm{m^2\, s^{-1}}$|⁠ ; and (6) presence of a solid-state greenhouse effect parts of the time. The data and the analysis provide a first empirical glimpse of how ice-rich cometary material ages and evolves when exposed to solar heating. [ABSTRACT FROM AUTHOR]

The geologically complex Kyzylzharma groundwater field is located in the south-central part of Kazakhstan in the lower Syr Darya Basin. It supplies the 243,000 population of Kyzylorda City by drinking and agricultural water needs. Numerical modeling was used to predict the consequences of increased groundwater withdrawal for future water supply needs. The results displayed a mean squared error for the groundwater simulations of about 0.6 m and was thus acceptable. The validated transmissivity was between 2 x 10-7 and 2 x 10-5 m/d. These parameters showed that the planned groundwater withdrawal will result in a depression cone reaching 90-100 m below present levels in 2040. Maximum groundwater level drawdown may reach 130 m below present levels. This drawdown increases risks for brackish saltwater intrusion into the main groundwater aquifer. The results point at the depletion of groundwater resources in the Syr Daria Artesian Basin and the risks for groundwater quality, particularly increase in mineralization. The key outcome is the recognition that effective joint management of the Syr Daria Artesian Basin's groundwater resources, involving both Kazakhstan and Uzbekistan, necessitates development and operation of a joint numerical aquifer model. Building this model is a crucial tool for assessing the sustainable groundwater resources in the region. [ABSTRACT FROM AUTHOR]

In recent decades, geophysical and remote sensing monitoring techniques have advanced to the point where they can be utilized. It is possible to investigate the spatiotemporal mass fluctuations induced by groundwater changes over the Southern Arabian Peninsula (SAP) by combining time-variable gravity data with land surface model outputs and rainfall data. Here are the findings: The average annual precipitation rates for the whole study region were 91.11, 87.6, and 96.61 mm yr−1 during the entire period (2002–2021), period before 2013, and period after 2012, respectively. The southern and eastern parts (Zone I) of the investigated region show modest rainfall rates of 109.6, 105, and 117 mm yr−1 during the whole period, period before 2013, and period after 2012, respectively. The Rub El Khali region (Zone II) is receiving lower precipitation rates of 54.6, 53.3, and 56.5 mm yr−1 throughout the whole period, period before 2013, and period after 2012, respectively. Based on the three distinct gravity solutions, the average Terrestrial Water Storage (ΔTWS) values are computed through the entire period to be − 0.21 ± 0.011, − 0.15 ± 0.013, and − 0.32 ± 0.0107 cm yr−1 for the whole study region, Zone of the southern and eastern regions, and Zone of Rub El Khali, respectively. The whole study region, Zone of the southern and eastern parts, and Zone of Rub El Khali are showing highly negative ΔTWS in the period before 2013, in comparison to slightly negative to slightly positive ΔTWS trends in period after 2012. The average annual change in groundwater storage for the entire study area was calculated at − 0.21 ± 0.011, − 0.29 ± 0.024, and − 0.091 ± 0.038 cm yr−1 throughout the investigated period, period before 2013, and period after 2012, respectively. Zone of Rub El Khali is showing higher negative groundwater storage trend (ΔGWS) averaged at − 0.32 ± 0.104 cm yr−1 throughout the investigated period, whereas Zone of southern and eastern regions is showing lower negative groundwater storage trend of − 0.15 ± 0.013 cm yr−1. Most of the recharge rate occurs in Zone of the southern and eastern regions reaching up to + 0.77 ± 0.092 cm yr−1 by taking the average groundwater withdrawal rate of + 0.92 ± 0.092 cm yr −1 during the whole period. This integrated approach is a valuable and economical method for more effectively assessing the variations of groundwater resources across wide areas. • Gravity application in groundwater storage estimation. • Geophysical monitoring of groundwater resources. • GRACE and GLDAS applications to groundwater storage variation in the Southern Arabian Peninsula. [ABSTRACT FROM AUTHOR]

In recent years, multi-bucket foundations have been studied and gradually adopted in engineering practices as a novel foundation for offshore wind turbines within a range of water depth of 30 to 50 m. This study investigated the motion characteristics of air-floating tripod bucket foundation (AFTBF) through a series of experiments during free air-floating. The experimental results show that the surge force appears to be the most important factor influencing pitch moment and motion, whether it is a change in water depth or a draft for AFTBF. The maximum amplitudes of surge acceleration and pitch angle show a trend of increasing with narrower spacing and decreasing with wider spacing, while the heave acceleration shows an opposite trend. The added mass and damping of heave motion for AFTBF increase with shallower water due to the increasing pressure difference between the inside and bottom of bucket foundation. The shallower the water depth and the larger the draft, the longer the resonance period of heave. [ABSTRACT FROM AUTHOR]

Enhancing the comprehension of alterations in land use holds paramount importance for water management in semi-arid regions due to its effects on hydrology and agricultural economics. Allowing agricultural land to lie fallow has emerged as a technique to decrease water use. This research employs the methodology of system dynamics modeling to evaluate the hydrologic and agricultural economic ramifications of employing the fallowing strategy, which aims to preserve water resources in interconnected socio-hydrologic systems. This strategy is explored across three different crops, focusing on the Mesilla–Rincon Valley (MRV) in southern New Mexico. The study's timeline spans from 2022 to 2050 with historical background from 1969 and encompasses various dimensions, including water availability, land utilization, and agricultural economics. Three types of crops were selected for the fallowing strategy, including cotton, alfalfa/hay, and chile. For each crop, 2500 acres of it would be designated for fallowing separately in two subsequent years, allowing the land to be cultivated in the third year and recurring such pattern. Simulation findings across scenarios (GFDL, UKMO, and NCAR) indicate that water withdrawals for all crops decreased significantly, ranging from approximately 2.69% to 4.37%. Similarly, agriculture income experienced reductions, varying from around 1.53% to 2.26%. Also, surface water and groundwater withdrawals are represented as percentages. The data illustrate significant reductions in water withdrawals across all scenarios. For instance, in the GFDL scenario, surface water withdrawal decreased by approximately 1.85% for cotton, 2.56% for alfalfa/hay, and 1.58% for chile. Similarly, groundwater withdrawals saw substantial reductions, such as 14.93% for cotton, 20.44% for alfalfa/hay, and 12.62% for chile. These numbers emphasize the urgent need for sustainable water management practices to address the challenges posed by reduced water availability. [ABSTRACT FROM AUTHOR]

This study combined a catchment model and one-dimensional lake model (GLM-AED) to simulate the response of hydrodynamics and water quality of subtropical Advancetown Lake (South-East Queensland, Australia) to future changing climates from 2040 to 2069 and 2070 to 2099 under Representative Concentration Pathway (RCP) 4.5 and 8.5 and increased water demand from a 50% increase in population over current levels. The simulation adequately reproduced water temperature (RMSE of 0.6 °C), dissolved oxygen (DO) (RMSE of 2 mg/L), and other water quality variables, such as nitrogen, phosphorus, and chlorophyll a (Chl-a). Warming temperatures dominated the change in thermal structure and hydrodynamic status of the lake under future climate change conditions. Projected changes in precipitation and hydrological response from the upstream catchment might, however, partly offset the warming temperatures under future climate change. Increased water withdrawal due to population growth, which involved water extraction from the epilimnion, showed antagonistic effects on water stability compared to those from climate change. Under a high emission scenario of RCP8.5 during the 2080s, there is an increased likelihood of winter turnover failure in Advancetown Lake. Nutrient concentrations were simulated to decrease from reduced catchment loads under future climate change conditions. However, Chl-a concentrations were simulated to increase, especially during the period after winter turnover, under these future conditions. The depth of the hypoxia front during stratification is expected to decrease and move towards the water surface, attributable to the warming water temperatures and prolonged thermal stratification, which might affect biogeochemical processes and exchange fluxes between the hypolimnion and bottom sediments. These potential changes may present challenges for water resource management under future conditions of climate change and population growth. [ABSTRACT FROM AUTHOR]

Due to the rapid exploitation of water resources in the Huixian karst wetland in the southwest of China in the past decades, the wetland has suffered from shrinkage in size and serious degradation of ecological functioning. To assess how much water within the wetland could still be taken out for local supply purposes while the wetland can still be kept in its normal ecological functioning. Through the use of multi-methods, including field surveys by a multi-disciplinary team, water balance, Remote Sensing, GIS and numerical simulation, this paper characterizes the wetland regime of the study area and finally determines scenarios of water resource utilization for local water supply within acceptable parameters of wetland ecological health. Through the analysis of the methods, it was found that the hydrological characteristics of the study area were conditioned by not only the karst water but also the regional precipitation fluctuations. A zone of mobile watersheds for Lake Mudong was established as opposed to a conventional single watershed. If the wetland ecosystem is kept at the current status of class III, a scenario of withdrawal of up to 20% of lake inflows could be accommodated. The results and their approaches would provide much-needed information for the protection of the wetland and its sustainable water utilization per se. It would offer a basic reference for similar problems in karst areas of southwest China and other areas alike. [ABSTRACT FROM AUTHOR]

India is a global hotspot for irrigation-induced groundwater withdrawal, leading to widespread lowering of water levels, in turn resulting in disproportionate access to irrigation supplies among farming communities. Efforts to mitigate the situation, however, have fallen short, largely due to technocentric vision (e.g. microirrigation adoption) of the regulatory authorities (RAs), which does little to integrate the vast groundwater-dependent socioecologies with the decision making system. In view of that, we invite the RAs to deliberate upon a cap-and-trade mechanism that proposes to mobilize the farmers at every aspect of planning and execution, while to tackling multiple challenges simultaneously: (a) restrict groundwater pumping to a pre-defined safe level (cap), (b) creating a shared space/quotas for all to pump (allocation); and (c) making provisions for trade of allocations. The latter further augments farmers' access to groundwater (and irrigation). Using a systematic bibliometric analysis of relevant world literature and contextual appraisal of groundwater-irrigation landscape in India, we develop a conceptual framework of cap-and-trade in three parts. In the first Pre-implementation stage, we emphasize a reality check study to assess ground conditions, if favorable for a cap-and-trade approach (existing social, economic, institutional circumstances). Next, in the Implementation stage, (1) we recommend an integrated hydrogeological-hydrometeorological modeling to determine flexible capping arrangements, with the possibility of delineating certain priority regions (coastal ecosystems); (2) for allocations, a reasonable fraction of the cap over a defined period; we envision a thoroughly participatory arrangement, centering on four action areas: identifying, informing, consulting, and involving the farmers, alongside all stakeholders engaged in the groundwater-irrigation decision making; (3) for trade, we urge the RAs to create win-win situations for both the sellers and buyers; develop the transaction protocols on certain foundational principles (e.g. simplicity, transparency and consistency); strengthening of local institutions, and development of targeted financial support schemes. We consider the third part of the narrative, Post-implementation stage, as a real game changer, comprising of a monitoring, auditing (performance benchmarking) component coupled with multitiered outreach-mentoring drives that demonstrate to the farmers the benefits of becoming part of the cap-and-trade program. Overall, a main motivation to present this research is to shatter the age-old socio-cognitive beliefs/taboos around groundwater pumping (My land, My Water), breaking the hegemony of the water sellers (rich/wealthy large landholder clans), to potentially, create a social norm whereby the farmers realize the value of restricting groundwater pumping and sharing for mutual prosperity. [ABSTRACT FROM AUTHOR]

Understanding the long‐term effects of population and GDP changes requires a multisectoral and regional understanding of the coupled human‐Earth system, as the long‐term evolution of this coupled system is influenced by human decisions and the Earth system. This study investigates the impact of compounding economic and population growth uncertainties on long‐term multisectoral outcomes. We use the Global Change Analysis Model (GCAM) to explore the influence of compounding and feedback between future GDP and population growth on four key sectors: final energy consumption, water withdrawal, staple food prices, and CO2 emissions. The results show that uncertainties in GDP and population compound, resulting in a magnification of tail risks for outcomes across sectors and regions. Compounding uncertainties significantly impact metrics such as CO2 emissions and final energy consumption, particularly at the upper tail at both global and regional levels. However, the impact of staple food prices and water withdrawal depends on regional factors. Additionally, an alternative low‐carbon transition scenario could compound uncertainties and increase tail risk, particularly in staple food prices, highlighting the influence of emergent constraints on land availability and food‐energy competition for land use. The findings underscore the importance of considering and adequately accounting for compounding uncertainties in key drivers of multisectoral systems to enhance our comprehensive understanding of the complex nature of multisectoral systems. The paper provides valuable insights into the potential implications of compounding uncertainties. Plain Language Summary: Understanding how future population and economic growth changes could impact our energy, water, food, and environment requires looking across multiple sectors and regions. This is because these systems are all connected. For example, increasing population drives higher food demand but requires more energy and water to grow food. At the same time, reducing greenhouse gas emissions from energy through increased biofuel consumption can compete with food production for land resources. This study explored how uncertainties in future population and GDP growth could compound and interact to affect future energy use, water withdrawal, staple food prices, and carbon dioxide emissions. Using a model that connects all these systems, the study found that combined uncertainties in population and GDP lead to more significant risks of extreme outcomes than individually looking at those uncertainties. There are substantial regional differences in future outcomes, like higher uncertainty in food prices for India and West Africa compared to other regions. We highlight the need to consider multisector and multisystem interactions between uncertainties across different regions. Accounting for these compounding uncertainties provides valuable insights into potential risks, like higher extreme projections for food prices or water use. These insights are essential for long‐term planning in our connected human‐Earth system. Key Points: Long‐term implications of population and GDP changes on the coupled human‐Earth system focusing on multisectoral and regional understandingUncertainties in GDP and population growth can compound, resulting in more extreme outcomes for multisectoral systemsCompounding uncertainties differ by region and metrics; staple food prices and water withdrawal show significant regional variability [ABSTRACT FROM AUTHOR]

The construction of dams and interbasin water transfers are major strategies to adapt to water scarcity. In the semi-arid Jaguaribe basin, Brazil, large strategic reservoirs supply water for urban centres, while farm dams serve multiple demands of rural communities. We used the Model of Water Availability in SemiArid Environments (WASA) to assess the water storage dynamics of strategic reservoirs impacted by: (i) water withdrawal from farm dams located upstream; (ii) interbasin water transfer to the Jaguaribe basin. Simulations show that intensive water use from smaller reservoirs reduces large reservoir volumes by less than 10%, whereas inflows from the São Francisco Integration Project to the basin can increase by 6% the period of time in which reservoir capacity is above the alert volume. The practice of saving water from small dams can be abandoned, enabling higher agricultural production without compromising the water supply of large urban centres. [ABSTRACT FROM AUTHOR]

The discharge of low-temperature water from the middle and lower layers of thermally stratified dam reservoirs leads to thermal pollution and adversely affects fish production and reproduction in downstream rivers. Selective water withdrawal using stoplog gates is an effective approach to address this issue. However, comprehensively and effectively evaluating the effects of stratified withdrawal and optimizing the scheduling of stoplog gates to provide better ecological services to downstream habitats pose significant challenges for reservoir managers. In this study, an equivalent elevation method (EEM) was developed based on in situ observation data of water temperature. The EEM calculates the equivalent withdrawal elevation (EWE) in the far dam area corresponding to the discharge-water temperature (DWT), facilitating the evaluation of stoplog-gate effects. EEM was applied to a thermally stratified dam reservoir in southwestern China (Guangzhao reservoir, GZ). The results showed a significant positive correlation (r > 0.7, p < 0.05) between DWT and the vertical-water-temperature structure in the far dam area. The average EWEs for the 5-layer, 4-layer, and 3-layer stoplog gates in GZ were 697.2 m, 690.8 m, and 689.9 m, respectively. Utilizing the EEM findings, a scheduling operation scheme was proposed to improve DWT while reducing the number of stoplog-gate operations, thereby increasing their efficiency and saving the cost of invested labor and time. This method provides a reference for reservoir managers in optimizing stoplog-gate-scheduling strategies to mitigate potential risks to aquatic ecosystems caused by abnormal water temperature. [ABSTRACT FROM AUTHOR]

Background: Precisely predicting the water levels of rivers is critical for planning and supporting flood hazard and risk assessments and maintaining navigation, irrigation, and water withdrawal for urban areas and industry. In Hungary, the water level of rivers has been recorded since the early nineteenth century, and various water level prediction methods were developed. The Discrete Linear Cascade Model (DLCM) has been used since 1980s. However, its performance is not always reliable under the current climate-driven hydrological changes. Therefore, we aimed to test machine learning algorithms to make 7-day ahead forecasts, choose the best-performing model, and compare it with the actual DLCM. Results: According to the results, the Long Short-Term Memory (LSTM) model provided the best results in all time horizons, giving more precise predictions than the Baseline model, the Linear or Multilayer Perceptron Model. Despite underestimating water levels, the validation of the LSTM model revealed that 68.5‒76.1% of predictions fall within the required precision intervals. Predictions were relatively accurate for low (≤ 239 cm) and flood stages (≥ 650 cm), but became less reliable for medium stages (240–649 cm). Conclusions: The LSTM model provided better results in all hydrological situations than the DLCM. Though, LSTM is not a novel concept, its encoder–decoder architecture is the best option for solving multi-horizon forecasting problems (or "Many-to-Many" problems), and it can be trained effectively on vast volumes of data. Thus, we recommend testing the LSTM model in similar hydrological conditions (e.g., lowland, medium-sized river with low slope and mobile channel) to get reliable water level forecasts under the rapidly changing climate and various human impacts. Highlights: The actual use of the DLCM predicts water stages less precisely than the LSTM model. The LSTM underestimates water stages on each predicted horizon (1–7 days). The LSTM model reacts too late or incorrectly in certain hydrological situations (rising limb of floods, medium stages). The most precise forecast was given for low stages, followed by floods. The lowest accuracy was provided for medium stages. [ABSTRACT FROM AUTHOR]

In Canada's Northwest Territories (NT), industrial activities conducted during the winter, such as ice road construction and exploratory drilling, require the use of water from ice-covered water bodies. Withdrawal in excess of 10% of available under-ice volume can threaten fish habitat or other users. The Land and Water Boards (LWBs) of the Mackenzie Valley require water licences for water withdrawal beyond regulated thresholds. Applicants must provide information including identification and location of proposed water sources, timing and proposed volume of water and winter water withdrawal must be limited to ,10% of available volume to protect fish habitat under the ice. Many applicants are at early project stages and the necessary information on bathymetry and volumes of water is not readily available or requires expertise and effort that may not be feasible at the early stages of smaller projects. This paper describes the alternative method for determining available winter water volumes from lakes to support small-scale projects. A simple formula of 'allowable volume (m3) - surface area (m2) * 0.1 m' was developed and tested to provide a conservative estimate of under-ice volumes from easily available data which is protective in spite of uncertainties inherent in limited data. [ABSTRACT FROM AUTHOR]

Anthropogenic water regulation activities, including reservoir interception, surface water withdrawal, and groundwater extraction, alter riverine hydrologic processes and affect dissolved organic carbon (DOC) export from land to rivers and oceans. In this study, schemes describing soil DOC leaching, riverine DOC transport, and anthropogenic water regulation were developed and incorporated into the Community Land Model 5.0 (CLM5.0) and the River Transport Model (RTM). Three simulations by the developed model were conducted on a global scale from 1981–2013 to investigate the impacts of anthropogenic water regulation on riverine DOC transport. The validation results showed that DOC exports simulated by the developed model were in good agreement with global river observations. The simulations showed that DOC transport in most rivers was mainly influenced by reservoir interception and surface water withdrawal, especially in central North America and eastern China. Four major rivers, including the Danube, Yangtze, Mississippi, and Ganges rivers, have experienced reduced riverine DOC flows due to intense water management, with the largest effect occurring in winter and early spring. In the Danube and Yangtze river basins, the impact in 2013 was 4 to 5 times greater than in 1981, with a retention efficiency of over 50 %. The Ob river basin was almost unaffected. The total impact of anthropogenic water regulation reduced global annual riverine DOC exports to the ocean by approximately 13.36 ± 2.45 Tg C yr -1 , and this effect increased from 4.83 % to 6.20 % during 1981–2013, particularly in the Pacific and Atlantic oceans. [ABSTRACT FROM AUTHOR]

The huge decrease in water volume in the Aral Sea, which was caused predominately by enormous water withdrawals from the Aral Sea tributaries, has changed the former world's fourth-biggest inland lake into a new desert called Aralkum. Due to its long-term use in agriculture, persistent organic pollutants (POPs), including organochlorine pesticides (OCPs), and polychlorinated biphenyls (PCBs) play a special role in the pollution of the Aral Sea tributaries and in the Aral Sea itself. For the first time, POPs, OCPs, and PCBs were studied in the Large Aral Sea, Small Aral Sea, and the Syrdarya River. PCBs and OCPs in the collected water samples were analyzed using gas chromatography. The results of long-term and inter-annual analyses of POPs in water resources of the Kazakh part of the Aral Sea–Syrdarya Basin are presented. The analyses covered the Large and Small Aral Seas, the Syrdarya River, reservoirs, lakes of the river delta, and drainage water of the collectors from irrigation areas. The inflow to the Syrdarya River that came from the collector–drainage water was the main cause of water pollution. The pollution levels of toxic compounds, including the trends of temporal and spatial changes in pollutant concentrations, were analyzed and assessed. The latest studies from 2021 and 2022 show a decrease in pesticide concentrations by tens and hundreds of times. [ABSTRACT FROM AUTHOR]

The low level of water and regulation of the Don River runoff led to an irreversible transformation of natural hydrological and hydrochemical processes. At the end of 2022, despite the shortage of river water, the region began laying a water pipeline with a capacity of up to 300 000 m3 of water per day to the Donbass. Are there enough water reserves for the increasing economic needs throughout the year? This work is based on a targeted study of the chemical composition of water under different regimes and sea levels on the Taganrog seashore of the Don Bay and delta. The experiment covers the period from December 2, 2022, until January 30, 2023, and single measurements, for comparison, on February 21, March 30, and April 17, 2023. In total three types of ionic composition typical of the Svinoe delta arm of the Don River are distinguished: first, marine with a dominant (>80%) total amount of sodium and potassium ions, chlorides, and salinity up to 7–9 g/L. Second, the waters of the Don correspond to low salinity (<2 g/L), an increased proportion of Na+ + K+ (50–60%), and a close amount of SO and HCO (30–40% each). Third, since 2018, groundwaters have been regularly recorded when the level decreases. These are medium brackish waters with a salt content >5 g/L. They typically have a high content of sodium and potassium (>60%) and sulfate ions (60–80%). Monitoring shows that the deficit of fresh drinking water will increase, and with increasing withdrawal of water, the deficit will accelerate in time. It will be replaced (up to 5–7 g/L) by mineralized groundwater and water from the Black Sea. The proportions of slightly brackish (2–4 g/L) and medium brackish (4–8 g/L) waters to be pumped (redistributed by seasons) into water pipelines still need to be explored. [ABSTRACT FROM AUTHOR]