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In dry months, there are acute water shortages as a result of reservoir water being released to improve reliability based on the full supply of needs in certain months. This study provides a method that stores some water from rainy months in the reservoir to be released during dry months to reduce failure during those times. The method is based on reservoir zoning and uses a multi-objective optimization system. The multi-objective gray wolf optimization (MOGWO) and multi-objective reptile search algorithm (MORSA) are connected to the WEAP simulator model and contrasted for this purpose. The primary goal of this type of system is to propose a solution that raises the proportion of demand supplied during dry months while maintaining an acceptable level of demand supply reliability across the entire duration. Ultimately, the role curve is assessed using the outcomes of two scenarios: the OS and the RS (depending on the actual circumstances). The findings demonstrate that MORSA outperforms MOGWO in terms of response quality and convergence time. The RS results show that in many dry years, particularly the last planning years, the percentage of supply for demand in three to five consecutive months is equal to zero in most uses, and in the remaining low-water years, it is less than five percent in the same months. In the best-case scenario, the percentage of demand during these months ranges from 30 to 60% thanks to optimization of the dam's rule curve using MORSA. Furthermore, in low-water months, the OS increases the proportion of meeting downstream environmental obligations. This study demonstrates that applying this strategy results in appropriate reservoir management and lessens the degree of failure when providing different uses during low-water months. [ABSTRACT FROM AUTHOR]

Quarrying of rock aggregates generates produced water that, if not handled properly will be a source of pollution for nearby water bodies, thus affecting the chemistry of the water. This study examined the chemistry, impact of quarrying activities on water resources and the health consequences/risks posed by ingestion of the water by humans in the Akamkpa quarry region in southeastern Nigeria. Thirty (30) water samples consisting of pond water, stream water, hand dug wells, and borehole samples were collected and analyzed for their physicochemical parameters using standard methods. The results obtained from the analyses indicated that the water was moderately acidic, fresh, and not salty, with many parameters below the recommended standards with Ca2+, and HCO3− being the dominant ions present in the water resources. Rock weathering processes including silicate weathering as illustrated by hydrochemical facies, cross plots, and Gibbs diagrams are the dominant mechanisms influencing the quality and major ions chemistry of the water resources with minor contributions from dissolution, anthropogenic activities, and ion exchange. Ca-Mg-SO4-Cl and Na–K-HCO3− are the most important water types. Although the water quality index shows that the water is suitable for human use and irrigation, the mean values of As, Cd, Pb, and Se are above the acceptable limits. Additionally, the calculated contamination factor revealed the water resources are moderate to highly contaminated by As, Cd, Cr, Mo, Pb, Sb, and Se, and are therefore unsuitable for consumption with regards to these parameters. However, the residual sodium carbonate and water hazard index (WHI) values showed that 38% to 90% of sites in the quarry area were unsuitable for cultivation, 10–30% were in the low to medium impact category, and 60% were classified as risky and are from high to very high impact category. A non-cancer study of inhabitants living in the vicinity of the quarry area indicated that 6.7% of the sites have values greater than one, indicating that it may endanger the health of the people. Therefore, constant monitoring of the water quality is recommended as long-term use of contaminated water can harm humans, plants, and soils. [ABSTRACT FROM AUTHOR]

A key to achieving the 17 Sustainable Development Goals is the sustainable provisioning of clean water and sanitation services. The sustainable management of water resources strengthens resilience, protects livelihoods, fosters economic growth, and contributes to poverty reduction. This paper reviews the challenges faced by Caribbean Small Island Developing States (SIDS) with a focus on water resource management. While the Caribbean region is seemingly blessed with water resources, with more than 90% of Caribbean residents having access to improved water, it faces challenges due to inefficient management and diverse geographical realities, creating spatial disparities. Furthermore, economic and physical scarcity coexist with some islands lacking proper infrastructure and others nearing the exhaustion of natural freshwater reserves. Climate change intensifies these issues through variable precipitation patterns and extreme weather events. Additionally, the region's dependence on tourism and susceptibility to environmental pressures necessitates a focus on targets related to SDGs 1 and 8. To address increasing water stress within the region, it is becoming increasingly urgent to identify root causes and develop targeted solutions that consider socioeconomic and environmental factors. The promotion of Integrated Water Resource Management is a key strategy for encouraging increased investment in climate-resilient infrastructure and fostering sustainable financing practices. Article Highlights: Caribbean islands face water scarcity due to climate change, population growth, and outdated infrastructure. Effective water management strategies are crucial for ensuring access to clean water and supporting local economies. Collaborative efforts and investments in resilient infrastructure can enhance water security across the region. [ABSTRACT FROM AUTHOR]

This paper explores the historical context and current dynamics of the transboundary water issues between India and China. Both countries share multiple transboundary river basins, with the Brahmaputra River being one of the most significant. The importance of the Brahmaputra River to both nations goes beyond just providing resources. It has implications for national security, regional stability, and human livelihoods. However, China's upstream control over the river and its extensive dam-building projects have raised concerns in downstream India and Bangladesh about potential impacts on water availability, agriculture, and livelihoods. The river system is critical for the socioeconomic well-being of millions of people, yet the competing demands for water resources have led to geopolitical tensions. The paper highlights China's strategic use of water resources, including plans for large-scale dams, which India views as a potential threat to its water security. It also underscores the importance of a nuanced understanding of hydropolitics, emphasizing the need for human security, particularly water security, in addressing these challenges. It argues that while "water wars" are unlikely, "water tensions" are significant and must be addressed through comprehensive bilateral agreements and collaborative efforts. [ABSTRACT FROM AUTHOR]

Sorption-based atmospheric water harvesting (SAWH) has received unprecedented attention as a future water and energy platform. However, the water productivity of SAWH systems is still constrained by the slow sorption kinetics at material and component levels and inefficient condensation. Here, we report a facile method to prepare hygroscopic interconnected porous gel (HIPG) with fast sorption-desorption kinetics, high scalability and stability, and strong adhesion property for highly efficient SAWH. We further design a solar-wind coupling driven SAWH device with collaborative heat and mass enhancement achieving continuous water production. Concentrated sunlight contributes to enhancing the desorption and condensation synergistically, and natural wind is introduced to drive the device operation and improve the sorption kinetics. The device demonstrated record high working performance of 14.9 Lwater m−2 day−1 and thermal efficiency of 25.7% in indoor experiments and 3.5–8.9 Lwater m−2 day−1 in outdoor experiments by solar concentration without any other energy consumption. This work provides an up-and-coming pathway to realize highly efficient and sustainable clean water supply for off-grid and arid regions. Sorption-based atmospheric water harvesting (SAWH), despite great promise, is constrained by slow sorption kinetics and inefficient condensation. Here the authors synthesize a hygroscopic interconnected porous gel with excellent sorption kinetics and high scalability and adopt solar concentration strategy for efficient continuous SAWH. [ABSTRACT FROM AUTHOR]

The continued threat from climate change and human impacts on water resources demands high-resolution and continuous hydrological data accessibility for predicting trends and availability. This study proposes a novel threefold downscaling method based on machine learning (ML) which integrates: data normalization; interaction of hydrometeorological variables; and the application of a time series split for cross-validation that produces a high spatial resolution groundwater storage anomaly (GWSA) dataset from the Gravity Recovery and Climate Experiment (GRACE) and its successor mission, GRACE Follow-On (GRACE-FO). In the study, the relationship between the terrestrial water storage anomaly (TWSA) from GRACE and other land surface and hydrometeorological variables (e.g., vegetation coverage, land surface temperature, precipitation, and in situ groundwater level data) is leveraged to downscale the GWSA. The predicted downscaled GWSA datasets were tested using monthly in situ groundwater level observations, and the results showed that the model satisfactorily reproduced the spatial and temporal variations in the GWSA in the study area, with Nash-Sutcliffe efficiency (NSE) correlation coefficient values of 0.8674 (random forest) and 0.7909 (XGBoost), respectively. Evapotranspiration was the most influential predictor variable in the random forest model, whereas it was rainfall in the XGBoost model. In particular, the random forest model excelled in aligning closely with the observed groundwater storage patterns, as evidenced by its high positive correlations and lower error metrics (Mean Absolute Error (MAE) of 54.78 mm; R-squared (R²) of 0.8674). The downscaled 5 km GWSA data (based on random forest) showed a decreasing trend in storage associated with variability in the rainfall pattern. An increase in drought severity during El Niño lengthened the full recovery time of groundwater based on historical storage trends. Furthermore, the time lag between the occurrence of precipitation and recharge was likely controlled by the drought intensity and the spatial recharge characteristics of the aquifer. Projected increases in drought severity could further increase groundwater recovery times in response to droughts in a changing climate, resetting storage to a new tipping condition. Therefore, climate change adaptation strategies must recognise that less groundwater will be available to supplement the surface water supply during droughts. [ABSTRACT FROM AUTHOR]

The water deficit resulting from climate variations limits the profitability and sustainability of sugarcane fields, making water supply through irrigation necessary to sustain the potential production of sugarcane. However, the water used for irrigation purposes must be properly managed, ensuring the conservation of water resources and the reduction of costs with the use of inputs and energy. Pulsed drip irrigation aims to support irrigation management, improving the efficient use of water and mitigating the deleterious effects of water deficit. This study aims to evaluate the growth, productivity, and industrial yield of sugarcane cultivated under continuous and pulsed drip irrigation. A field experiment was conducted at the Experimental Sugarcane Station of Carpina, in Carpina in the State of Pernambuco, Northeast Brazil, from December 2020 to December 2021. The experimental arrangement was randomized blocks in a 2 x 5 factorial design, with two types of irrigation application (pulsed and continuous) and five irrigation levels (40, 60, 80, 100, and 120% of crop evapotranspiration – ETc), with four replications. Pulsed drip irrigation increased the yield of stalks (9%) and sugar (21%) in the sugarcane crop and ethanol (17%) derived from sugar in the juice. Pulsed drip irrigation, when compared to continuous irrigation, improved the performance of sugarcane, providing a reduction in water consumption and increasing growth, stalk yield, sugar and predicted ethanol yield. Thus, based on this study, pulse irrigation is an efficient approach to irrigation management, contributing to the stability of sugarcane production while conserving water relative to continuous irrigation. [ABSTRACT FROM AUTHOR]

Early Southern Mesopotamia shows a complex history of expansion of (irrigated) farming in relation to urban developments and changing landscapes. As a first step to study expanding irrigated farming system, an irrigation-related agent-based model was developed to explore farm(land)s and irrigation systems in relation to decision-making processes, both of farms and their farmlands (an agriculture unit) and collective decision-making processes for irrigation system management—especially sharing water between farms. The decision-making processes include options to move farms, expand the system, or start a new system, as these would be options available for Mesopotamian farmers as well. In this text, we report how model parameters contribute to the generation of various patterns of yields and expansion of farms and system. Additionally, the Gini coefficient (based on yields) is applied to estimate levels of inequality among farmers. Our results show how (1) human decision-making determines the level of influence of and benefits for farms, as well as the overall irrigation system; (2) Gini values effectively capture the degree of inequality in yields among farms based on water availability; and (3) our model is a suitable base for further study, by incorporating additional agents into the irrigation system and expanding the spatial–temporal scales of the irrigated landscapes, to reach a more comprehensive understanding of the evolutionary dynamics of irrigation systems in Southern Mesopotamia. [ABSTRACT FROM AUTHOR]

Drought poses a serious threat to the productivity of hop, an important perennial crop. However, the precise physiological mechanisms that make it highly susceptible to drought are not yet fully understood. In this study, we investigated stomatal regulation and xylem vulnerability to embolism, which are important traits closely associated with plant drought resistance. In a glasshouse cultivation experiment, we monitored changes in leaf water potential, stem elongation rates, and leaf gas exchange, including net photosynthetic rates, stomatal conductance, and intrinsic water use efficiency, on relatively young hop plants (traditional Saaz - Osvald's clone 31) exposed to declining soil water availability. The transpiration rate and stem elongation of plants decreased significantly with a small decline in substrate water potential (ΨSUB), indicating a highly sensitive stomata response during early phases of soil dehydration. The stem elongation was completely halted, and the transpiration rate dropped to less than 50% of its maximum at ΨSUB levels below − 0.8 MPa. In well-watered hop plants, xylem in stems operates near the initial point of embolization and is highly vulnerable to embolism, with a water potential corresponding to a 50% loss of xylem conductivity at -1.6 MPa. The sensitive stomatal response to declining ΨSUB likely helps to mitigate the risk of hydraulic failure, albeit at the cost of impaired growth. Scheduled irrigation, particularly during the sensitive stem elongation stage, may be a promising approach to mitigate the detrimental effects of reduced soil water availability on hop growth and yield while also conserving water resources. [ABSTRACT FROM AUTHOR]

Polylepis (Queñua) is a dominant woody plant genus in Andean Puna forests that occurs in a wide range of montane habitats and is ecologically diverse in endemism, which may be particularly threatened by climate change. Wood anatomical traits are essential for understanding how plants adjust their ecophysiological requirements and maximize their resilience, resistance, and recovery to extreme climates. Although the effects of extreme climatic conditions in high altitude ecosystems have been studied extensively, our knowledge is relatively limited to quantitative differences in the main xylem tissues. To address this gap, we assessed the acclimation of wood anatomical traits in six Peruvian Andean Polylepis species with different water availability (semi-dry with high moisture and semiarid with dry winters). We selected hydraulic diameter, vessel density, vessel grouping index, solitary vessel index, vulnerability index, mesomorphy index, vessel element length, fiber length, fiber wall thickness, fiber lumen diameter, and total fiber diameter that can provide relevant eco-wood anatomical acclimation to hydric stress. We performed multivariate analysis to determine the leading dimensions of covariation among Polylepis species and climatic factors. Specific wood anatomical traits (vessel grouping index, vulnerability index, and fiber wall thickness) were dissimilar between xeric- and mesic-Polyelpis species. This study demonstrates that wood anatomical traits in Peruvian Andean Polylepis species provides high-resolution and long-term eco-wood anatomical signals on how climate oscillations drive the acclimation processes of fiber and vessel traits. Our findings underscore the significance of xylem hydraulic adjustment to various hydrological environments in Andean puna forests. By evaluating the effects of drought on wood anatomical characteristics and ecological function, we demonstrate the capacity of tree species to adapt and endure climate-related changes, thereby emphasizing their resilience and adaptability. [ABSTRACT FROM AUTHOR]

Monitoring regeneration in woody communities and understanding the drivers of its success is crucial for gaining insight into the long-term persistence of trees in African drylands, where they play key socio-ecological roles. While fire, grazing and water availability are key factors for regeneration in these ecosystems, seed arrival, germination and seedling recruitment are still poorly documented under natural conditions in the West African Sahel. Tree planting is commonly carried out in West Africa to promote regeneration. The cost is considerable, the success is variable and its influence on spontaneous regeneration is unknown. We conducted a field inventory to ascertain the regeneration ability of woody communities in a Sahelian savanna in three land management types (plantations, communal grazing, old enclosures) to determine (i) the proportion of the different regeneration mechanisms; (ii) the influence of adult trees; (iii) the influence of management type and topography and (iv) their temporal dynamics. We first showed that regeneration diversity was poor, with half of the adult species not recorded in the regeneration phase. Secondly, regeneration mostly came from true seedlings compared to resprouting. Thirdly, adult communities were found to greatly influence regeneration density and composition. Fourthly, topography proved to influence regeneration density, whereas we observed little effect of the land management type. Lastly, historical data highlighted a steep decline in regeneration density over recent decades. These results raise questions about the persistence of woody vegetation in Sahelian savannas and highlight the need to protect large trees in suitable microsites, such as topographic depressions, to promote regeneration. [ABSTRACT FROM AUTHOR]

Increased tree mortality associated with hotter-drought events has rarely been recorded in mature (>10 years old) commercial plantations. However, we report a recent (2021–2022 warm season) event of this kind that occurred across the Mesopotamian region of Argentina, South America. We aimed to elucidate the mortality timing, rate, and magnitude associated with environmental and stand characteristics at local scale to determine which conditions make these productive systems more vulnerable to extreme climatic events. Using Sentinel-2 satellite images and field-data we estimated the canopy mortality from November 2021 to October 2022, in Pinus spp afforestations (mainly P. taeda). We found that spatio-temporal heterogeneity in canopy mortality was associated with variation in soil and topographic characteristics, but not in stand age and size. We found that canopy mortality occurs at greater extent, earlier and faster in shallow soils (≤ 0.6 m), while the lowest mortality occurred at depressed and waterlogged areas. Intermediate levels of mortality were observed in deep soils (> 1 m), where relatively higher mortality occurred in areas with shallow water table signs, inhibiting deep root development. Our results suggest that sites allowing a deeper rooting system and/or where soil water availability is expected to be higher and long-lasting could represent areas with low-mortality risk for fast-growing pine plantations. [ABSTRACT FROM AUTHOR]

Cover cropping is practiced in conservation agriculture to preserve soil and water resources, alleviate soil compaction, sequester organic carbon, and control weeds. Meanwhile, cover cropping is rarely used in forestry, probably due to the lack of awareness of this management practice. In this short essay, we discuss the concept of utilizing cover crops to prepare degraded lands for afforestation or reforestation projects. The benefits of this practice are similar to those in agriculture. The risks of this practice are mostly related to plant-plant interactions, and particularly, to the potential competition for resources with the target trees. As such, this practice should be implemented cautiously, to prevent adverse impacts on the forest system. Also, attention should be paid to ensure the delivery of ecosystem services and functions by the target land. Further, the co-use of complementary practices may be considered to accelerate the success rate of cover cropping in degraded lands designated for afforestation and reforestation. Among these practices, application of soil additives, such as composts, manures, and biochars, may be useful in increasing soil concentrations of organic carbon and nutrients, thus improving soil quality and fertility. Additional complementary active practices may be the direct seeding or planting of nurse shrubs and trees, as well as the inoculation of soil surface with biocrust slurries, aimed to increase ecosystem complexity by forming a multi-story vegetation structure. Recommendations and guidelines for implementing cover crops in forestry should be site-specific and case-dependent, and consider both the desired benefits and potential risks. [ABSTRACT FROM AUTHOR]

The ability of non-native plant species to tolerate water scarcity and high temperatures, especially during the early stages of development, may influence their invasive potential. Ligustrum lucidum is a tree native to warm temperate areas of Asia. To understand the potential expansion of this non-native invasive species into more arid regions, we conducted an experiment in incubation chambers to evaluate seed germination under different water potentials and the response of its seedlings under different water availability and temperature scenarios. Seeds were collected from central Argentina and placed to germinate under four different water potentials (−0.2; −0.4; −0.7 and −1.2 MPa) created with polyethylene glycol 6000. Additionally, L. lucidum seedlings were subjected to contrasting levels of water availability combined with different periods of exposure to high temperatures. Germination measurements (germination percentage, velocity, and synchronicity) decreased at lower water potentials. No germination occurred at −0.7 and −1.2 MPa. The seedlings showed a slight increase in mortality and a significant reduction in most of the growth variables under low water availability, while exposure to high temperatures had significant effects only on chlorophyll estimate. The germination response of L. lucidum to water deficits could pose a significant constraint on its establishment in arid ecosystems. Nonetheless, this constraint may be alleviated by the species' prolific propagule production, coupled with asynchronous seed germination, which may help it exploit more humid micro-sites or sporadic water events. Furthermore, the drought tolerance of its seedlings strongly warns against the use of this species as an ornamental plant in arid environments. [ABSTRACT FROM AUTHOR]

Clean water supply in low-income countries can be improved by utilizing affordable renewable energy-powered desalination technologies. In this research work, viability of community scale solar desalination plant (at least 3.0 m3/d capacity) capable of addressing the daily fresh water demands of hundred families in twenty three coastal locations of Somalia has been investigated through year-round simulations. The required desalination plant size and investment is heavily dependent on solar radiation potential of the site. The potable water production cost ranges between 8.66 to 9.48 USD/m3, and is lower than the nonreliable conventional water supply cost in eighteen Somalia coastal locations. Moreover, the desalination plant can sooth at least 2.5 to 13.6-kilo tons of CO2 emission, 6.0 to 33.3-tons of SO2 emission and, 2.30 to 12.6-tons of NOX emission during its 5.0 to 25.0 years operation period. The sustainability index and finance payback time of community scale solar desalination plant is about 1.08, and 4.0 to 13.0 years, respectively. The economics and environmental foot print results indicate feasibility and potential application of community scale solar desalination plant in water starved Somalia coastal locations. [ABSTRACT FROM AUTHOR]

Summary: Purpose: This study was carried out to determine the presence of Entamoeba histolytica in water sources of Niğde province in Turkey, between June and November 2021. Methods: A total of 90 water samples were taken from 15 different water sources (drinking water, well water, spring water, wastewater and dam water) every month and the presence of E. histolytica antigens in the samples was examined by ELISA. Results: The positivity for E. histolytica was determined in 7 (7.7%) of 90 samples. While no antigens were found in any of the samples in June and September, E. histolytica was positive for three samples (20%) in July, one sample (6.6%) in August and October and two samples in November (13.3%). One of 24 dam samples (4.1%), 1 of 12 wastewater samples (8.3%), 1 of 12 well samples (8.3%), and 4 of 24 fountain samples (16.6%) that examined by ELISA were found positive. On the other hand, none of the examined 18 spring samples were positive. In addition, 4 (8.8%) of 45 samples that examined in summer and 3 (6.6%) of 45 samples that examined in autumn were detected positive by using ELISA. Entamoeba histolytica positivity in samples was statistically insignificant in terms of months, water resources and seasons (P > 0.05). Conclusion: As a result, the presence of E. histolytica, which is an important public health problem in water sources, was determined for the first time in Niğde province of Türkiye with this study. [ABSTRACT FROM AUTHOR]

Hydrological droughts severely affect the demand of water for domestic water supply, irrigation, hydropower generation, and several other purposes. The pervasiveness and consequences of hydrological droughts necessitate a thorough investigation of their characteristics, which is hindered due to unavailability of continuous streamflow records at desirable resolutions. This study aims to assess the hydrological drought characteristics and their spatial distribution using high-resolution Global Flood Awareness System (GloFAS) v3.1 streamflow data for the period 1980 to 2020. Streamflow Drought Index (SDI) was used to characterize droughts at 3-, 6-, 9-, and 12-monthly timescales starting from June, i.e., the start of water year in India. GloFAS is found to capture the spatial distribution of streamflow and its seasonal characteristics. The number of hydrological drought years over the basin varied from 5 to 11 during the study duration, implying that the basin is prone to frequent abnormal water deficits. Interestingly, the hydrological droughts are more frequent in the eastern portion of the basin, i.e., the Upper Narmada Basin. The trend analysis of multi-scalar SDI series using non-parametric Spearman's Rho test exhibited increasing drying trends in the easternmost portions. The results were not similar for the middle and western portions of the basin, which may be due to presence of a large number of reservoirs in these regions and their systematic operations. This study highlights the importance of open-access global products that can be used for monitoring hydrological droughts, especially over ungauged catchments. [ABSTRACT FROM AUTHOR]

Water governance demands multi-sector participation beyond the state; and, appropriate laws, policies, regulations, and institutions need to be developed and put in place for sustainable use of water resources. A good water policy, a critical and integral instrument of water governance, guides water use schemes and ensures equitable water distribution among users. The Ethiopian Central Rift Valley (CRV) is rich in water resources, but these water resources are currently under severe strain owing to an imbalance in human-water interactions. This study examined the state of water resources governance framework, policy coherence, actors' engagement and transparency, accountability, and participation in irrigation water supply in the CRV of Ethiopia. Key informant interviews (KII), focused group discussions, and document reviews were used to gather data for the study. The NVivo 11 program was used to organize, code, and analyze the data. The results revealed that water resources governance practices such as water allocation and apportionment, water resources protection, and conservation activities were inappropriately exercised. Water resources management policy mechanisms were not fully put in place. Lack of coherence in water policy implementation, absence of clear roles and responsibilities of stakeholders, absence of transparency and accountability in irrigation water service delivery, and lack of meaningful participation of key actors in water governance decision-making were observed. As a result, over-abstraction, deterioration of buffer zone areas, and chemical erosion from surrounding farming are attributed to the reduction in water volume and quality in the CRV. These challenges have influenced aquatic ecosystem services and threaten the livelihoods of the surrounding communities. Hence, reforms relating to policy coherence and enforcement, stakeholder engagement, water distribution strategies, and the implementation of water governance principles must be given adequate emphasis. [ABSTRACT FROM AUTHOR]

Water consumption dynamics lead to pressure fluctuations at network nodes, potentially associated with pipe leakages or unreliable supply within a water distribution system. Efficient management of secondary water supply system (SWSS) could enhance inflow modes of its essential component (i.e., storage tank) of potential implication on pressure control and water quality maintenance. In this study, a novel computational framework was developed to determine the optimal inflow profiles of storage tanks, where a water supply system simulation model was integrated with the particle swarm algorithm-based optimization for demand peak staggering. Experimental investigations on an example water supply system revealed that, as compared to the control of float ball valves, the optimizing regulation of SWSS tanks remarkably reduced water pressure oscillations by approximately 70%, correspondingly with the minimum pressure elevating and the maximum pressure declining among network nodes. Furthermore, the enhancing regulation schemes allowed water levels to fluctuate within an effective range, thus decreasing water retention time and facilitating associated water quality safety. Sensitivity analysis from our simulations indicates that increasingly appropriate tank number and size magnified the regulation capability, thereby reinforcing the promotion effect of optimizing control schemes on the system performance. The proposed approach is expected to provide theoretical support for optimizing the dynamic operations and management of SWSSs. [ABSTRACT FROM AUTHOR]

Widespread flooding in Africa has devastating repercussions on communities, and sometimes leading to loss of life, displacement of populations, and significant damage to infrastructure and agriculture. Despite this, there are limited studies that investigate the behaviour of high time frequency river flows for the major river systems of Africa to inform adaptation and mitigation strategies for improved resilience of society. This paper fills this gap by assessing the occurrence time of annual maximum daily discharge for five of the longest rivers of Africa using a statistical modelling approach. This is the first of such a study covering all of the five longest rivers of Africa in one paper. Annual maximum daily discharge time for each river was modeled by mixtures of von Mises distributions, fitted by a Markov chain Monte Carlo algorithm. Data on mean daily discharge was obtained from the Global Runoff Data Centre database for the Niger, Zambezi, Okavango, Limpopo and Orange rivers in Africa. Estimates were inferred for the location parameter of the major mode, location parameter of the minor mode, concentration parameter of the major mode, concentration parameter of the minor mode, mean time, mean resultant, circular variance, circular skewness, and circular kurtosis. The developed models reveal distinctive temporal patterns of peak discharge events in each river, which can have significant implications for flood management, water resource planning, hydrological modeling, risk assessment and infrastructure design. [ABSTRACT FROM AUTHOR]

Drought is a global threat caused by the persistent challenges of climate change. It is important to identify drought conditions based on weather variables and their patterns. In this study, we enhanced the Standardized Precipitation Index (SPI) by integrating ground temperature data to develop a more comprehensive metric for evaluating drought severity: the Multivariate Standardized Drought Index. Our metric offers a dual assessment of drought severity, taking into account both the intensity of the drought and its duration. We employ this evaluation in a primary paddy cultivation region of Sri Lanka, with the aim of shedding light on the prevailing drought conditions affecting paddy crops due to insufficient water supply and prolonged periods of elevated temperatures. Additionally, we calibrate our metric by aligning it with historical drought records and subsequently compare the outcomes with those derived from the conventional SPI. [ABSTRACT FROM AUTHOR]

The coast of south-western Bangladesh has been facing an increasing severity of climate stressors, thereby affecting the livelihoods of households. This has necessitated the importance of understanding the complex aspects of their sustainability. This study investigates factors influencing household income and livelihood sustainability of coastal residents in southwestern Bangladesh. A survey was carried out among 300 heads of households from the Kailashganj and Laudubi villages under Dacope sub-district of Khulna district (a climate-sensitive region) in Bangladesh. We utilized the composite livelihood sustainability index (LSI) and multiple linear regression to identify the factors influencing coastal households' income. Findings revealed that the overall LSI among the households was 0.663 (moderate sustainability). Additionally, the highest LSI was found in terms of social capital and the lowest LSI was identified in terms of financial capital. The findings of the regression analysis indicated that monthly household income was positively and significantly influenced by its close linkages to local leaders (p < 0.05) and association with non-governmental organizations (p < 0.01). Moreover, economically active members (p < 0.01), more accessibility of commuting transportation (p < 0.01), and availability of water for irrigation (p < 0.01) were positively and significantly derived the monthly household income. Policymakers can use these results as a basis for formulating policies (e.g., enhancing the training and skill development programs as well as prioritizing investment in expanding irrigation systems) that can address the essential livelihood and income requirements of the community that is affected by climate change. [ABSTRACT FROM AUTHOR]

The Tibetan Plateau, often referred to as Asia's water tower, is a focal point for studying spatiotemporal changes in water resources amidst global warming. Precipitation is a crucial water resource for the Tibetan Plateau. Precipitation information holds significant importance in supporting research on the Tibetan Plateau. In this study, we estimate the performance and applicability of Climate Prediction Center Merged Analysis of Precipitation (CMAP), Integrated Multi-Satellite Retrievals for Global Precipitation Measurement (IMERG), Global Land Data Assimilation System (GLDAS), and Global Precipitation Climatology Project (GPCP) precipitation products for estimating precipitation and different disaster scenarios (including extreme precipitation, drought, and snow) across the Tibetan Plateau. Extreme precipitation and drought indexes are employed to describe extreme precipitation and drought conditions. We evaluated the performance of various precipitation products using daily precipitation time series from 2000 to 2014. Statistical metrics were used to estimate and compare the performances of different precipitation products. The results indicate that (1) Both CMAP and IMERG showed higher fitting degrees with gauge precipitation observations in daily precipitation. Probability of detection, False Alarm Ratio, and Critical Success Index values of CMAP and IMERG were approximately 0.42 to 0.72, 0.38 to 0.56, and 0.30 to 0.42, respectively. Different precipitation products presented higher daily average precipitation amount and frequency in southeastern Tibetan Plateau. (2) CMAP and GPCP precipitation products showed relatively great and poor performance, respectively, in predicting daily and monthly precipitation on the plateau. False alarms might have a notable impact on the accuracy of precipitation products. (3) Extreme precipitation amount could be better predicted by precipitation products. Extreme precipitation day could be badly predicted by precipitation products. Different precipitation products showed that the bias of drought estimation increased as the time scale increased. (4) GLDAS series products might have relatively better performance in simulating (main range of RMSE: 2.0–4.5) snowfall than rainfall and sleet in plateau. G-Noah demonstrated slightly better performance in simulating snowfall (main range of RMSE: 1.0–2.1) than rainfall (main range of RMSE: 2.0–3.8) and sleet (main range of RMSE: 1.5–3.8). This study's findings contribute to understanding the performance variations among different precipitation products and identifying potential factors contributing to biases within these products. Additionally, the study sheds light on disaster characteristics and warning systems specific to the Tibetan Plateau. [ABSTRACT FROM AUTHOR]

Artificial recharge of groundwater has been recognized as a promising option for sustaining groundwater supplies and ensure water security for the ever rising population. With the aid of geospatial and multi-criteria decision analysis methodologies, the current study's scope aids in evaluating groundwater potential zones and locating suitable zones and sites for groundwater recharge for the revival of the Kanari River. A pragmatic methodology was suggested in this study for implementing water harvesting structures for river revival and estimation of water demand, pumping, and recharge. The geometric mean and the normalized weight for individual features were specified using the AHP in a GIS environment. All the different features/datasets were overlaid, and possible groundwater zones were revealed using AHP. Integrated maps were used to identify the groundwater recharge zone and locations for establishing artificial recharge structures within the Kanari River system. Ultimately, the domestic water demand, agriculture water use, pumping, and livestock water demand were estimated for water budgeting, and based on this data, the water availability was calculated. Based on the study results, the water demand of the Kanari River watershed was estimated to be 732 MCM. Taking into consideration the supply and demand scenarios, the pumping overdraft of the Kanari River watershed was found to be 423 MCM, and the proposed additional recharge through the planned conservation structures was estimated to be 859 MCM. So, even if pumping overdraft is considered, this additional groundwater recharge can fulfill the local demand, help maintain the river flow, and ensure water availability and security in the region. [ABSTRACT FROM AUTHOR]

Rooftop rainwater harvesting (RRWH) offers a potential solution to Jordan's pressing water scarcity problems. Yet, its feasibility and benefits necessitate a thorough assessment, particularly as existing studies on the subject are outdated and often constrained by limited scope or small data sets. To this end, our study assessed the potential of RRWH in Jordan's 12 governorates, utilizing historical rainfall data from 1987 to 2018 and official statistics on population and rooftop areas. The analyses used the Ripple Method and Water Balance Model to determine potential harvestable water volumes, potential water-saving percentages, and optimal tank sizes under different scenarios (i.e., using rainwater to meet the total consumption or only for toilet flushing). The findings reveal that Jordan has a total potential for rooftop rainwater harvesting amounting to 23.74 Mm3/year, corresponding to 4.54% of the total water demand. Should RRWH be implemented across all rooftops, the projected financial savings for Jordan could range from $170 million to $678 million. Among the governorates, Irbid and Amman have the highest potential, with estimated yields of 7.754 Mm3 and 8.453 Mm3 per year, respectively. Based on the best results for the scenario where harvested rainwater is only used to flush toilets, the optimal tank sizes for storing rainwater were estimated to be 2.7 m3 and 2 m3 per household in Ajlun and Irbid, respectively. For a regularized case (October–May), a payback period of 12.5–24 years based on desalination cost was found for an RRWH system capable of meeting thrice the flushing needs of a household. RRWH was showcased as a sustainable solution to Jordan's water scarcity, emphasizing the necessity for broader implementation. [ABSTRACT FROM AUTHOR]

Italy is the leading rice producer in Europe and the second in the Mediterranean basin (after Egypt), with most of the production concentrated in a large paddy area between the Lombardy and Piedmont regions (northern Italy). In this area, irrigation of rice was traditionally carried out by wet seeding and continuous flooding; in the last fifteen years, this technique has been gradually replaced by dry seeding followed by a delayed flooding (DFL) or by an alternation of flooding and dry periods (FTI), which are economically more advantageous. This study presents the results of an extensive monitoring campaign designed and carried out in 2021 in a representative paddy district of the Lomellina area (Pavia, northern Italy) to assess the impact of the actual rice cropping strategies on surface water and groundwater quality, with particular attention to two widely used herbicides (MCPA and clomazone) and to nutrient losses (e.g., N, P, K). Results show that MCPA and clomazone concentrations detected in surface water and groundwater are always below the RAC (Regulatory Acceptable Concentration) values. As to nutrients, they do not show significant trends along the season in surface water and groundwater: this may be due to the fact that nutrient sources are many. Concerning the concentrations, nitrates may pose a problem for the area, especially for groundwater. However, further studies would be needed to understand to which extent rice cropping can be considered the major source of contamination for water resources. [ABSTRACT FROM AUTHOR]

Potentially toxic elements (PTEs), especially arsenic in drinking water, pose significant global health risks, including cancer. This study evaluates the groundwater quality in Giresun province on the Black Sea coast of Türkiye by analyzing twelve groundwater resources. The mean concentrations of macronutrients (mg/L) were: Ca (10.53 ± 6.63), Na (6.81 ± 3.47), Mg (3.39 ± 2.27), and K (2.05 ± 1.10). The mean levels of PTEs (µg/L) were: Al (40.02 ± 15.45), Fe (17.65 ± 14.35), Zn (5.63 ± 2.59), V (4.74 ± 5.85), Cu (1.57 ± 0.81), Mn (1.02 ± 0.76), As (0.93 ± 0.73), Cr (0.75 ± 0.57), Ni (0.41 ± 0.18), Pb (0.36 ± 0.23), and Cd (0.10 ± 0.05). All PTE levels complied with WHO drinking water safety guidelines, and overall water quality was excellent. The heavy metal evaluation index (HEI < 10) and heavy metal pollution index (HPI < 45) indicate low pollution levels across all stations. Irrigation water quality was largely adequate, as shown by the magnesium hazard (MH), sodium adsorption ratio (SAR), Na%, and Kelly's ratio (KR). The total hazard index (THI) values consistently remained below 1, indicating no non-carcinogenic health risks. However, at station 10 (city center), the cancer risk (CR) for adults due to arsenic was slightly above the threshold (1.44E-04). Using principal component analysis (PCA), positive matrix factorization (PMF), and geographic information system (GIS) mapping, the study determined that most PTEs originated from natural geological formations or a combination of natural and human sources, with minimal impact from human activities. These findings highlight the safety and reliability of the groundwater sources studied, emphasizing their potential as a long-term, safe water supply for nearby populations. [ABSTRACT FROM AUTHOR]

Carbon emissions and water consumption are both important factors affecting sustainable development. Therefore, it is necessary to put them in the same research framework and investigate the synergy. In this study, the dynamic evolution characteristics of the synergistic effect of reducing carbon and saving water (RCSW) were analyzed. Then, taking the Yangtze River Delta Urban Agglomerations (YRDUA) as the research object, the influencing factors and specific paths of the synergistic effect were clarified. The results showed that the low-carbon emission efficiency (LCEE) had a stable synergy with the intensive utilization efficiency of water resources (IUEWR) in the YRDUA. Government financial expenditure, actual use of foreign capital, and population density were the most significant driving forces for the synergistic effect of RCSW, with q values of 0.561, 0.363, and 0.240, respectively. In addition, most of the interactions of the driving factors were nonlinear enhancement and double-factor enhancement. [ABSTRACT FROM AUTHOR]

The Thar is the most densely populated desert in the world, which supports diverse ecosystems and human endeavours such as agriculture and socioeconomic activities. Water demand and supply in the Thar play an essential role in regulating the socioeconomic activities of the region. Inland water and precipitation aid the movement of water in the Thar Desert. Precipitation in the Thar is governed by the Indian Summer Monsoon (ISM), during which the winds distribute water vapour to regulate precipitation across the region. Therefore, we analyse the water vapour, its sources and its relation with precipitation using satellite measurements and reanalysis data in the Thar during ISM. Like other regions, a clear seasonal cycle of water vapour is observed in the Thar, with very high values (> 45 kg/m2) during ISM and low in winter (< 15 kg/m2). Evapotranspiration and moisture transport have significant effects on the amount of water vapour during ISM. There is a significant increase in water vapour in the troposphere, with high trends at the surface (0.032 g/kg/year) and small at the tropopause (0.00002 g/kg/year). A significant increase in column water vapour is also estimated in the Thar during ISM, with high trends in the eastern and southern areas, at about 0.15–0.35 kg/m2/year. The rise in water vapour in the Thar can be attributed to the increase in evapotranspiration (0.03–0.07 mm/day/year) and water vapour transport (> 0.5 kg/m/s/year) from the Arabian Sea and Indian Ocean. The rise in water vapour can lead to an increase in precipitation in the Thar, as it shows significant positive trends (0.05–0.1 mm/day/year) in the eastern areas during ISM. The increase in precipitation and water vapour in the arid Thar Desert can have significant implications for the regional environment and agriculture. [ABSTRACT FROM AUTHOR]

The critical importance of water makes it an indispensable natural resource. In context of urban infrastructure, particularly in the developing world, supplying water to urban households poses a notable challenge. Optimizing water supply systems (WSS) is one of the most arduous challenges in addressing this issue, primary contributors being energy and water losses during supply process. This paper focuses on the method adopted for minimizing losses in WSSs and creating a self-sustainable model for water supply in the urban settlement of Dehradun, India. The solution entails deployment of Energy Savings Companies (ESCO) service delivery model and the utilization of Supervisory Control and Data Acquisition (SCADA) system. This approach, thus far has yielded saving in both revenue, energy and water consumption at source, potentially generating saving that would enable covering the operational and maintenance changes for the established system for around 10 years. [ABSTRACT FROM AUTHOR]

Universal and equitable access to affordable safely managed drinking water (SMDW) is a significant challenge and is highlighted by the United Nations' Sustainable Development Goals-6.1. However, SMDW coverage by 2030 is estimated to reach only 81% of the global population. Solar water evaporation (SWE) represents one potential method to ensure decentralized water purification, but its potential for addressing the global SMDW challenge remains unclear. We use a condensation-enhanced strategy and develop a physics-guided machine learning model for assessing the global potential of SWE technology to meet SMDW demand for unserved populations without external electricity input. We find that a condensation-enhanced SWE device (1 m2) can supply enough drinking water (2.5 L day−1) to 95.8% of the population lacking SMDW. SWE can help fulfill universal SMDW coverage by 2030 with an annual cost of 10.4 billion U.S. dollars, saving 66.7% of the current investment and fulfilling the SDG-6.1 goal. Solar water evaporation is regarded as a promising toolset for decentralized drinking water purification. This study predicts the global drinking water supply potential via solar water evaporation, highlighting where and how to promote solar evaporation devices to fulfill the United Nations Sustainable Development Goal 6.1 with reasonable costs. [ABSTRACT FROM AUTHOR]

Streamflow in source region of Yellow River (SRYR) matters with regard to the adjacent and downstream water resources. Intraseasonal oscillation (ISO) in the streamflow in SRYR is of great significance to the sub-seasonal prediction of streamflow in SRYR, but is unknown. Here, we first report a 30–60-day ISO in the streamflow in SRYR, which is regulated by the atmospheric 30–60-day ISO at mid-high latitude over North Eurasia. The 30–60-day ISO in atmosphere is featured by a Rossby wavetrain, and the wave energy propagates southward onto the TP, which causes anomalous wind response over TP. The leading anomalous high (low) with anti-cyclonic (cyclonic) wind anomalies over the TP favors dry (wet) air in lower troposphere in SRYR, via enhancing the water vapor divergence (convergence). Dry (wet) air always results in strong (weak) evaporation from the Yellow River, which causes the later streamflow valley (peak) and thereby the 30–60-day ISO in the streamflow in SRYR. [ABSTRACT FROM AUTHOR]

Climate models are indispensable tools for decision-making, yet their efficacy in characterizing climatic conditions in regions of complex topography, such as Central-Western Argentina (CWA), remains challenging. Therefore, the main objective of this study was to evaluate mean and extreme values of temperature and precipitation simulations from a set of CMIP6 climate models in CWA. The mean values were compared against CRU TS 4.05 for the period 1950–2014; and the extreme values against ERA5 for the temperature and ERA5, CPC, and CHIRPS for the precipitation during 1981–2010. To evaluate the mean values, we considered several statistical metrics that accounted for the representation of the annual cycle, the long-term trends, and the spatial patterns, followed by a selection of the climate models that best represent the region. Subsequently, we analyzed 20 climate extreme indices using Taylor Diagrams and box-and-whiskers plots. The CMIP6 models tended to exhibit a wet bias over CWA, with temperature simulations warmer (colder) than observations over the Andes (Lowlands). Moreover, most models adequately captured the increase in temperature, as well as the increase in precipitation in the lowlands and its decrease in the Andes. From the set of 24 precipitation and 12 temperature simulations, we evaluated the performance for the representation of climate extremes, finding that most models had difficulties with the quantification of indices based on percentiles. This climate information can be valuable to obtain more accurate climate projections for CWA and to aid decision-making in a region with significant wine production and high reliance on water resources. [ABSTRACT FROM AUTHOR]

Precipitation plays an important role in the water resources system in Tarim Basin (TB), the most arid region in China. However, the source of water vapor for precipitation and its linkages with climate circulations still keep mysterious. Based on the observed precipitation of 21 stations from 1961 to 2020 in TB and the NCAR/NCEP reanalysis data, the temporal and spatial variations of summer precipitation in TB and their linkages with the westerly, Asian summer monsoons and extratropical circulation are investigated. The results show that: (a) the summer precipitation in TB changes consistently at all 21 stations, and exhibits an increasing trend (4.1 mm/decade) from 1961 to 2020 with large interannual fluctuations; (b) although the water vapor in TB mainly comes from the westerly circulation, the water vapor from the edges of Asians summer monsoons also plays an important role. It is unexpectedly found that the summer precipitation in TB is negatively correlated with the Westerly Index (WI). When the upstream westerly wind weakens, the northeast wind from the eastern boundary and the southwest wind from the southern boundary strengthen, which bring more water vapor from the edges of East Asian and South Asian summer monsoons respectively, leading to abundant precipitation in TB; (c) when the Eastern Atlantic/Western Russian pattern (EA/WR) is in extreme negative phase, there is an anticyclone anomaly near 55°N, 55°E, which weakens the upstream westerly wind and reduces the water vapor input of western boundary into TB. However, the water vapor input from the edges of the Eastern and Southern Asian summer monsoon strengthens, facilitating abundant precipitation in TB. This study provides a new insight into the joint influence of westerly, monsoons and extratropical circulation on summer precipitation in TB, which is meaningful for understanding the mechanism of change in summer precipitation and the trend projection of future water resources. [ABSTRACT FROM AUTHOR]

Using automatic rainfall station and ERA5 reanalysis data, the Southwest China vortex (SWCV) processes that induce warm-sector rainstorms in the Sichuan Basin were analyzed, their environmental field and dynamic thermal characteristics were researched through physical diagnosis and dynamic synthesis, and the development mechanism was discussed. The results showed that for the warm-sector rainstorms caused by the SWCV (SWCV-WR), the general circulation backgrounds can could be divided into three types: upper trough-vortex (Type I), plateau shear line (Type II), and short-wave trough (Type III) types. Regarding the aspects of the maintenance of the SWCV, duration of the warm-sector rainstorms, and maximum hourly precipitation intensity, the influence of Type I is the most evident, followed by Types II and III for SWCV-WR. The vertical structure of the SWCV is shallow and inclined to the west with height, but the positive vorticity of Types I and II can reach up to 200 hPa for SWCV-WR. The pseudo-equivalent potential temperature in the vortex area is greater than 354 K, which is accompanied by an upward-energy tongue, and shallow secondary circulation occurs on the eastern side of the SWCV, promoting vortex development. Regarding the thermodynamic characteristics of SWCV, Type I is the strongest, followed by Type III, and Type II is the weakest. The water vapor supply in different types of SWCV-WR is not only closely related to the strength of water vapor transport in the Bay of Bengal, but also to the variations in water vapor transport caused by the influence of different water vapor sources, such as the South China Sea and western Pacific Ocean, during its transportation. For SWCV-WR, the vorticity advection presents an uneven east-west positive and negative distribution. Under the dynamic forcing, the positive vorticity on the east side of SWCV of Types I and II (III) is enhanced (weakened), while that on the west side is weakened (enhanced). Different atmospheric vorticity variations have different significant effects on the three types of SWCV-WR. Under the spatial non-uniform heating, the horizontal non-uniform heating effect on the different types of SWCV-WR has regional differences, while the vertical non-uniform heating effect has the largest effect on the spatial non-uniform heating and a positive heating effect on the three types of SWCV-WR. Therefore, the spatial non-adiabatic heating effect, particularly the vertical non-uniform heating effect, is an important mechanism for the development and evolution of SWCV and SWCV-WR. [ABSTRACT FROM AUTHOR]

The management of water resources is no longer an option but a necessity especially in countries with a high rate of population growth like Pakistan. Pakistan has a high-water scarcity, an extremely varying topography, and is also one of the countries encountering the problem of climate change. Therefore, prudent utilization of available water resources is a matter in the plains of Pakistan as in its high-altitude regions. Instead of wasting water which is a valuable resource, rainwater harvesting is a way of saving rainwater as an alternative source of fresh water for better use. The aim of this study was to search for potential rainwater-harvesting areas in a high-altitude Gilgit River basin. This research employed the SCS-CN technique in estimating surface runoff in the GIS environment. The geospatial study used four input parameters: slope of the land, land covers, surface runoff and drainage density. The research concluded that some lands, especially those that are deserted in dry area and agricultural lands, can serve as the sites of rainwater harvesting, with only 4% of area that was highly suitable for the purpose. Nevertheless, 37% of the investigated area was shown as totally unviable for rainwater collection installations because of steep slopes and substantial volume of snow. Simultaneously, the rainwater storage design solutions suggested were check dam, percolation tank, and agricultural ponds with the area of 3.5%, 1%, and 0.75% of the given land area, respectively, for rainwater harvesting. The locations of potential catchment and planned rainwater harvesting structures would assist the local authorities and the policy makers to provide plans and design on the construction of water storages and also the optimization of water use. [ABSTRACT FROM AUTHOR]

Aquatic plants play an important role in aquatic systems. A comprehensive understanding of their spatial distribution may help to develop biodiversity conservation plans. This work investigated the spatial distribution of aquatic plants across China, including the invasive, threatened, and province-endemic species. Correlation analysis was used to evaluate the effects of environmental variables on richness pattern and variation partitioning was used to reveal the pure and shared effects of four explanatory variable groups: energy-water availability, geographical location, habitat heterogeneity, and human impact on species richness. Results showed that aquatic plants were unevenly distributed in China and they decreased from southern China toward northern China. Yunnan Province was the hotspot of aquatic plants. The number of invasive species was more in southeast China and less in northwest China. The endemism of aquatic plants in each province was not obvious. Aquatic plant richness across China tended to be higher in areas where the energy and water supply are adequate and actual evapotranspiration was the strongest correlate for total species richness (r = 0.630). Among the three growth forms, the correlation between submerged species richness and environmental factors was weak, while that of floating plants was strong. According to variation partitioning, the shared effect of energy-water availability and geographical location was dominant in aquatic plant richness pattern across China (R2 = 0.47 for total species richness). Pure spatial factors had a weak effect in shaping the richness pattern, suggesting that dispersal limitations have no significant effect on the distribution pattern of aquatic plants for their relatively strong dispersal capacity. Moreover, the effects of habitat heterogeneity and human impact on total aquatic plant richness pattern were also weak. [ABSTRACT FROM AUTHOR]

The review paper delves into the intricacies of water quality index (WQI) and its relationship with land use and land cover in the Ganga River basin of Uttar Pradesh. The study highlights the significance of the Ganga River, a major perennial river in India, and presents findings from previous paper work shows that 57 sites of Ganga basin show fair, poor, or heavily polluted water quality. Analysis of live storage data within the basin revealed a notable increase in LULC compared to previous years, resulting in decrease water quality indicators such as low rate of dissolved oxygen (DO) levels and high concentrations of pollutants like faecal coliform, total coliform, and nitrate (NO3-). The observed increased in nitrate concentration, particularly attributed to enhance industrial activities and agricultural runoff during the harvesting season, suggests a negative trend towards water quality restoration. The prevalence of untreated commercial and industrial wastewater remains a significant challenge to sustained water quality improvement. In conclusion, the paper advocates for addressing land use land cover of the Ganga basin and ensuring adequate flow releases to rejuvenate the river effectively. It underscores the need for comprehensive measures to sustainably manage land use and cover water resources and mitigate anthropogenic impacts on the middle Ganga River. [ABSTRACT FROM AUTHOR]

The existing consensus models of conflict decision-making generally assume that the decision-makers' preferences are simple and certain. This assumption oversimplifies the complexity of real-world conflicts due to the ignorance of the decision-maker's limited rationality. The present work makes the first attempt at solving this issue by defining the grey consensus and dissent preference of two decision makers (DMs), which is then embedded into the Graph Model for Conflict Resolution (GMCR) to obtain conflict equilibrium solutions. To be specific, preference relations are first described as interval grey scales to reflect the decision maker's judgments on conflict states, and then converted into crisp values to interface with GMCR. We next present both the logical and matrix representations under the GMCR framework, along with detailed pseudocode that can be implemented to investigate actual conflict situations practically. For validation and verification purposes, the proposed decision framework is applied to the water resource conflict of the Yellow River Basin in China, from which insights are derived to facilitate effective strategic decision-making for resolving complex conflicts in uncertain environments. [ABSTRACT FROM AUTHOR]

Recycled moisture is an important indicator of the renewal capacity of regional water resources. Due to the existence of Yulong Snow Mountain, Lijiang in Yunnan Province, southeast of the Qinghai-Tibet Plateau, China, is the closest ocean glacier area to the equator in Eurasia. Daily precipitation samples were collected from 2017 to 2018 in Lijiang to quantify the effect of sub-cloud evaporation and recycled moisture on precipitation combined with the d-excess model during monsoon and non-monsoon periods. The results indicated that the d-excess values of precipitation fluctuated between −35.6‰ and 16.0‰, with an arithmetic mean of 3.5‰. The local meteoric water line (LMWL) was δD = 7.91δ18O + 2.50, with a slope slightly lower than the global meteoric water line (GMWL). Sub-cloud evaporation was higher during the non-monsoon season than during the monsoon season. It tended to peak in March and was primarily influenced by the relative humidity. The source of the water vapour affected the proportion of recycled moisture. According to the results of the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, the main sources of water vapour in Lijiang area during the monsoon period were the southwest and southeast monsoons. During the non-monsoon period, water vapour was transported by a southwesterly flow. The recycled moisture in Lijiang area between March and October 2017 was 10.62%. Large variations were observed between the monsoon and non-monsoon seasons, with values of 5.48% and 25.65%, respectively. These differences were primarily attributed to variations in the advection of water vapour. The recycled moisture has played a supplementary role in the precipitation of Lijiang area [ABSTRACT FROM AUTHOR]

The Middle Route Project of South-to-North Water Diversion (MRP) has effectively increased the amount of available water resources in the receiving areas of the Beijing-Tianjin-Hebei region, curbed the trend of declining groundwater levels, expanded the area of landing funnels, and increased the magnitude of ground subsidence, and enabled the groundwater system to play an important ecosystem service value. This article classified groundwater ecosystem services in the receiving areas of Beijing-Tianjin-Hebei into four categories: provisioning services, regulating services, supporting services and culture services, according to the classification of the Millennium Ecosystem Assessment. We constructed an ecosystem service value assessment index system and a monetized quantitative value assessment model to assess the groundwater ecosystem services value (GESV) around the commissioning of the MRP, and analyzed the contribution of the MRP to the GESV. The results showed that the total annual average of the GESV in the receiving areas of Beijing-Tianjin-Hebei before the water connection was 124.298 billion yuan, and after the water connection was 144.033 billion yuan, of which the value of the regulating and supporting services increased and the value of the supply services decreased. The enhancement of the GESV in the water-receiving areas of Beijing-Tianjin-Hebei by the MRP has increased year by year, and its contribution to the GESV increased from 10.508 billion yuan in 2015 to 49.354 billion yuan in 2019. [ABSTRACT FROM AUTHOR]

The increase in water consumption along with climate change makes freshwater more vulnerable to pollution. Conserving the dwindling freshwater resources is one of the major problems faced by water management experts. Hence, forecasting lake water level (WL) fluctuations is crucial for managing water resources systems. As part of this study, the standalone support vector regression (SVR) model along with the hybrid SVR model combined with the algorithm of innovative gunner (AIG) was employed for WL multistep-ahead (1–3 months) forecasting of Michigan and Superior Lakes. The hybrid model takes advantage of the unique strength of individual models and it can be an effective way to improve forecasting performance. The average mutual information (AMI) and Taylor diagram techniques were applied for WL of lakes up to a lag of 20 months to determine the most effective inputs for model development. Multistep-ahead WL forecasting models of each lake were built based on the training subset (70%; from 1918 to 1991) and the testing subset (30%; from 1992 to 2021). The models were validated statistically and visually in the testing stage. Finally, based on the results, error values were found to be small for AIG-SVR models for both selected stations: Lake Michigan: 0.039 m < RMSE < 0.140 m and Lake Superior: 0.037 m < RMSE < 0.133 m. The test results also revealed that AIG-SVR model has boosted the accuracy of the results. The great potential of the AIG algorithm based on SVR as a novel model was proved in estimating accurate multistep lake WL values with high generalization ability and low variance compared to the SVR model for both lakes. [ABSTRACT FROM AUTHOR]

Water scarcity is becoming a common problem due to urbanization, industrialization, rapid population growth, and climate change. The situation is exacerbated in semi-arid and arid regions due to low or no rainfall and the resulting pronounced seasonality of river flows. Accurate assessment of reservoir operational performance plays a critical role in water resource sustainability and utilization. In this study, Water Evaluation and Planning (WEAP) models were developed to evaluate the operational performance of five reservoirs in the Yesilirmak Basin in Turkey. Since each reservoir is a single reservoir system, calibration of the WEAP model involved adjusting the approximate rule curves derived by the sequent peak algorithm and the allocation coefficient during hedging until the simulated reservoir storage states matched the observed ones as closely as possible. The agreement of the simulated storage capacities of the WEAP model with the measured volumes was evaluated using the coefficient of determination (R 2) and the Nash-Sutcliffe model efficiency coefficient (NSE). The results demonstrate that the WEAP model can be used to design and plan the operational strategies for the reservoirs in the Yesilirmak Basin. The performance of the reservoirs operated with the designed rule curves was evaluated using the reliability, resilience, vulnerability, and sustainability indices. For Cakmak, Corum and Yenihayat reservoirs, it is shown that these reservoirs are sufficient to meet the demand. The vulnerability of Alaca reservoir is only 1%, which is negligible. The vulnerability for Yedikir is 24% and the failure cannot be ignored. [ABSTRACT FROM AUTHOR]

This study is dedicated to the 300th anniversary of the Russian Academy of Sciences and the 80th anniversary of the establishment of the Institute of Limnology, Russian Academy of Sciences. The main results of studying Russian lakes in the Academy of Sciences over three centuries are presented. In the 18th century, the Academy of Sciences organized first "physical" expeditions for studying lakes, lake regions, as well as the Aral and Caspian seas. In 1916, a Commission for Studying Lake Baikal was set up at the Imperial St. Petersburg Academy of Sciences. After 1917, the studies of lakes expanded considerably because of the practical needs of the country's development. In 1928, the Presidium of the Academy of Sciences transformed the Baikal expedition into the Baikal Limnological Station. In 1944, the Laboratory of Limnology was created in Leningrad, and in 1971, the Institute of Limnology, of the USSR Academy of Sciences was created. In the 1970s–1980s, comprehensive studies of lakes and lake–river systems were carried out in the European part of the USSR along the design line of the redistribution of the water resources in the country. In 1970–1980, USSR Academy of Sciences participated in solving global problems of limnology—eutrophication, acidification, and pollution of lakes. In the late XX–early XXI centuries, special attention was paid to the assessment of the state and the development of forecasts of changes in the ecosystems of water bodies under various climatic and anthropogenic impacts. Monographs were published, generalizing the history of lakes studies in various parts of the country, and complex atlases of large lakes in Russia were compiled. The discovery of periglacial Lake Vostok in the Antarctic, and the obtained scientific results are outstanding scientific achievements in the late XX century. It is shown that lake studies by the Russian Academy of Sciences have contributed much to the basic science and to solving practical problems of the country's economy, and are significant for the development of problems of continental hydrology. [ABSTRACT FROM AUTHOR]

Small water supply systems (SWSSs) are often more vulnerable to waterborne disease outbreaks. In Japan, many SWSSs operate without regulation under the Waterworks Law, yet there is limited investigation into microbial contamination and the associated health risks. In this study, the microbiological water quality of four SWSSs that utilize mountain streams as water sources and do not install water treatment facilities were monitored for over 2 years. In investigated SWSSs, the mean heterotrophic plate counts were below 350 CFU/mL, and the total bacterial loads (16S rDNA concentration) ranged from 4.71 to 5.35 log10 copies/mL. The results also showed the consistent presence of fecal indicator bacteria (FIB), i.e., Escherichia coli and Clostridium perfringens, suggesting the potential of fecal pollution. E. coli was then utilized as an indicator to assess the health risk posed by E. coli O157:H7 and Campylobacter jejuni. The results indicated that the estimated mean annual risk of infection and disability-adjusted life years (DALYs) exceeded acceptable levels in all SWSSs for the two reference pathogens. To ensure microbial water safety, implementing appropriate water treatment facilities with an estimated mean required reduction of 5–6 log10 was necessary. This study highlighted the potential microbial contamination and health risk level in SWSSs that utilize mountain streams as water sources, even though the water sources were almost not affected by human activities. Furthermore, this study would also be helpful in supporting risk-based water management to ensure a safe water supply in SWSSs. [ABSTRACT FROM AUTHOR]

Rivers are vital and complex natural systems that provide a wide range of ecosystem services. This study presents a methodology for assessing the riverine provisioning and supporting ecosystem services, whose applicability has been demonstrated over the Budhabalanga River Basin of India. The Soil and Water Assessment Tool (SWAT) is used to generate streamflow time series at various ungauged sites, and then the streamflow is characterized for the evaluation of provisioning services. Further, the diversity and abundance of macroinvertebrates, along with the Lotic-invertebrate Index for Flow Evaluation (LIFE), is used to study the riverine supporting ecosystem services. The streams show intermittent behavior and strong seasonality for low flows, which limits the water availability, particularly during pre-monsoon season. The Baseflow Index (BFI) is greater than 0.6, indicating that groundwater contributes more than 60% of the total streamflow. Interestingly, despite the high BFI, the streams did not conform to the prevailing opinion that a greater baseflow contribution results in a later commencement of the low-flow period in the hydrological year. Furthermore, the study depicts significant variations in the diversity and abundance of the macroinvertebrates across the various sampling sites. However, the LIFE score across the sites remained consistent within a narrow range, i.e., 8 to 9, suggesting a steady supply of supporting ecosystem services. The results of the study can help the policymakers towards an informed decision making and the simplistic methodology proposed in this study can be replicated in other river basins for identifying vulnerable watersheds and prioritizing management actions. [ABSTRACT FROM AUTHOR]

Fluvial sediment analysis and water quality assessment are useful to identify anthropic and natural sources of pollution in rivers. Currently, there is a lack of information about water quality in the Pixquiac basin (Veracruz state, Mexico), and this scarcity of data prevents authorities to take adequate measures to protect water resources. The basin is a crucial territory for Xalapa, the capital city of Veracruz state, as it gets 39% of its drinkable water from it. This research analyzed 10 physicochemical parameters and 12 metal concentrations in various rivers and sources during two seasons. Dissolved metals presented average concentrations (µg/L): Al (456.25) > Fe (199.4) > Mn (16.86) > Ba (13.8) > Zn (7.6) > Cu (1.03) > Pb (0.27) > As (0.12) > Ni (0.118) (Cd, Cr and Hg undetectable). Metals in sediment recorded average concentrations (ppm): Fe (38575) > Al (38425) > Mn (460) > Ba (206.2) > Zn (65.1) > Cr (29.8) > Ni (20.9) > Cu (16.4) > Pb (4.8) > As (2.1) (Cd and Hg undetectable). During the rainy season, Water Quality Index (WAWQI) classified stations P17 and P18's water as "unsuitable for drinking" with values of 110.4 and 117.6. Enrichment factor (EF) recorded a "moderate enrichment" of Pb in sediment in P24. Pollution was mainly explained by wastewater discharges in rivers but also because of erosion and rainfall events. Statistical analysis presented strong relationships between trace and major metals which could explain a common natural origin for metals in water and sediment: rock lixiviation. [ABSTRACT FROM AUTHOR]

The Huaihe River basin is located in eastern and central China and in a climate transition zone. Its unique geographical location and climatic conditions have led to increases in flood waterlogging damage in the basin. The impact of climate change on water resources in the basin and the adaptability of these resources to these changes deserve attention. To achieve the objectives of climate resilient development, society and ecosystems must transform into a more resilient state. This dynamic process includes two stages: adaptation and resilience. In this study, elements of social resilience were integrated into adaptability analyses. Three aspects of the adaptation mechanism of water resource system are discussed: natural resilience, artificial adaptation, and social resilience. An index system that conforms to the process mechanism of water resource system adaptability was constructed. The fuzzy analytic hierarchy process was used to identify and analyse indexes of natural resilience, artificial adaptation and social resilience. Based on the adaptation mechanism of the water resource system and the original two-dimensional risk matrix, a method combining the connection number and three-dimensional risk matrix was established. In addition, a risk element combination table of a three-dimensional risk matrix and its chromatograms was obtained. Finally, an empirical study was conducted using the Huaihe River basin in Anhui Province, China, as an example. The results indicated that the adaptability level of the upper region of the Huaihe River basin in Anhui is higher than that of the lower region, and the adaptability level of the southern part is higher than that of the northern part. To improve the adaptability of water resource system in the lower and northern regions, targeted, evidence-based measures for strengthening water resource management in the Huaihe River basin are needed. [ABSTRACT FROM AUTHOR]

Water scarcity is an escalating global concern that poses significant challenges to agriculture. The need to feed a growing population, coupled with changing climate patterns, demands a re-evaluation of water use efficiency in major field crops. Water efficiency in agriculture is a critical facet of sustainable water management in rural areas, where agriculture often serves as a primary economic activity. In rural regions, where water resources are often limited, efficient agricultural water management is vital to ensure food security, economic stability, and environmental sustainability. In this review, we have discussed various measures to improve water use efficiency or productivity in agricultural systems. Adopting the strategies for enhancing water productivity at plant and field level may include: rain water harvesting in rural area, soil moisture conservation practices like mulching, crop residue retention and conservation agriculture, better utilization of stored soil moisture by best crop management interventions, irrigation scheduling, integrated farming systems i.e. multiple usage of water in agriculture by combining various farm enterprises like crop production, dairy and fishery. Beside these, reviewed the water use efficiency for important field crops around the world. Review also discussed about how beneficial public policies particularly watershed management in rural area are needed to establish the right socioeconomic conditions for boosting WUE in the agriculture. [ABSTRACT FROM AUTHOR]

Inter-basin water transfer projects are among the highly controversial issues in water supply policies. These projects have economic effects on the sources and destination areas. The costs and benefits of these projects should be investigated for their justification. This study examines the economic and welfare impacts of the Taleghan Water Transfer Project (TWTP) in Iran using a water-embedded multi-regional computable general equilibrium (WMRCGE) model. The results indicate that the increase in the equivalent variation (EV) of the water-receiving area is 6.9 times greater than the EV loss in the water supply area. Thus, the welfare improvement in the water-receiving area is much higher than the welfare loss in the water-supplying area. The results also indicated that the increase in total output in the water-receiving region is three times the total output reduction in the water supply region. [ABSTRACT FROM AUTHOR]