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Humanity faces a wide range of freshwater challenges and threats, from the failure to provide safe water and sanitation to all, to ecological disruptions and degradation, increasing violence over water resources, accelerating climate change, and failing institutions and infrastructure. In recent years, crises around minerals, energy, food, and water have stimulated new debates over definitions and concepts of sustainability—including whether the world is reaching a point where natural resource limits will constrain growing populations and economic expansion. Understanding the concept of "peak water" and the strategies that might be available to avoid these constraints is key to moving toward a more efficient and sustainable water future. [ABSTRACT FROM AUTHOR]

Water has been a factor in wars and other violent conflicts for thousands of years. Water can be a trigger of conflict, a casualty of conflict, or a weapon of conflict. In modern times, water-related conflicts appear to be increasing in number, with many of these occurring at the sub-state level, such as between opposing militant groups or between groups with different ethnic and cultural heritages. Action to prevent, mitigate, and recover from these conflicts is possible and available, but insufficiently applied. Investments in the broader effort to create more equitable, sustainable, resilient societies are urgently needed. The good news is that we no longer lack the technological capability to create that world, and action at all levels of society, from the local to the global, will help to foster peace and sustain and protect water resources for everyone. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFAS) are persistent chemicals of increasing concern to human health. PFAS contamination in water systems has been linked to a variety of sources including hydrocarbon fire suppression activities, industrial and military land uses, agricultural applications of biosolids, and consumer products. To assess PFAS in California tap water, we collected 60 water samples from inside homes in four different geographic regions, both urban and rural. We selected mostly small water systems with known history of industrial chemical or pesticide contamination and that served socioeconomically disadvantaged communities. Thirty percent of the tap water samples (18) had a detection of at least one of the 32 targeted PFAS and most detections (89 %) occurred in heavily industrialized Southeast Los Angeles (SELA). The residents of SELA are predominately Latino and low-income. Concentrations of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) ranged from 6.8 to 13.6 ng/L and 9.4-17.8 ng/L, respectively in SELA and were higher than State (PFOA: 0.007 ng/L; PFOS: 1.0 ng/L) and national health-based goals (zero). To look for geographic patterns, we mapped potential sources of PFAS contamination, such as chrome plating facilities, airports, landfills, and refineries, located near the SELA water systems; consistent with the multiple potential sources in the area, no clear spatial associations were observed. The results indicate the importance of systematic testing of PFAS in tap water, continued development of PFAS regulatory standards and advisories for a greater number of compounds, improved drinking-water treatments to mitigate potential health threats to communities, especially in socioeconomically disadvantaged and industrialized areas.

Despite some progress, universal access to safe water, sanitation and hygiene (WASH) by 2030-a remit of Sustainable Development Goal 6-remains a distant prospect in many countries. Policy-makers and implementers of the WASH sector are challenged to track a new path. This research aimed to identify core orienting themes of the sector, as legacies of past processes, which can provide insights for its future. We reviewed global policy, science and programmatic documents and carried out 19 expert interviews to track the evolution of the global WASH sector over seven decades. We situated this evolution in relation to wider trends in global health and development over the same time period.With transnational flows of concern, expertise and resources from high-income to lower-income countries, the WASH sector evolved over decades of international institutionalisation of health and development with (1) a focus on technologies (technicalisation), (2) a search for generalised solutions (universalisation), (3) attempts to make recipients responsible for environmental health (responsibilisation) and (4) the shaping of programmes around quantifiable outcomes (metricisation). The emergent commitment of the WASH sector to these core themes reflects a pragmatic response in health and development to depoliticise poverty and social inequalities in order to enable action. This leads to questions about what potential solutions have been obscured, a recognition which might be understood as 'uncomfortable knowledge'-the knowns that have had to be unknown, which resonate with concerns about deep inequalities, shrinking budgets and the gap between what could and has been achieved.

California agriculture will undergo significant transformations over the next few decades in response to climate extremes, environmental regulation and policy encouraging environmental justice, and economic pressures that have long driven agricultural changes. With several local climates suited to a variety of crops, periodically abundant nearby precipitation, and public investments that facilitated abundant low-priced irrigation water, California hosts one of the most diverse and productive agroecosystems in the world. California farms supply nearly half of the high-nutrient fruit, tree nut, and vegetable production in the United States. Climate change impacts on productivity and profitability of California agriculture are increasing and forebode problems for standard agricultural practices, especially water use norms. We highlight many challenges California agriculture confronts under climate change through the direct and indirect impacts on the biophysical conditions and ecosystem services that drive adaptations in farm practices and water accessibility and availability. In the face of clear conflicts among competing interests, we consider ongoing and potential sustainable and equitable solutions, with particular attention to how technology and policy can facilitate progress.

Populations consuming saline drinking water are at greater risk of high blood pressure and potentially other adverse health outcomes. We modelled data and used available datasets to identify countries of higher vulnerability to future saltwater intrusion associated with climate change in 2050 under Representative Concentration Pathways (RCP)4.5 and RCP8.5. We developed three vulnerability criteria to capture geographies with: (1) any coastal areas with projected inland saltwater intrusion of ≥ 1 km inland, (2) > 50% of the population in coastal secondary administrative areas with reliance on groundwater for drinking water, and 3) high national average sodium urinary excretion (i.e., > 3 g/day). We identified 41 nations across all continents (except Antarctica) with ≥ 1 km of inland saltwater intrusion by 2050. Seven low- and middle-income countries of higher vulnerability were all concentrated in South/Southeast Asia. Based on these initial findings, future research should study geological nuances at the local level in higher-risk areas and co-produce with local communities contextually appropriate solutions to secure equitable access to clean drinking water.

Objectives: To assess the effect of Community Water Fluoridation (CWF) in the prevalence of dental caries and dental fluorosis in 12-year-old children living in Israel. Considering that CWF is important in the prevention of dental caries. Between 2002 and 2014, the water in communities of at least 5,000 individuals was fluoridated. In 2014, CWF in Israel stopped. Method and materials: Data on 12-year-old children from all areas in Israel from the national cross-sectional epidemiological survey conducted in 2011 to 2012 were stratified by city water fluoridation and by city and school socioeconomic status. Two dependent variables were defined: (1) DMFT index of caries experience in the permanent dentition; (2) dental fluorosis in central incisors using the Thylstrup-Fejerskov classification of fluorosis. Results: Data from 2,181 12-year-olds were analyzed. The average DMFT was 1.17 ± 1.72, and 49% were caries-free. Based on DMFT, the caries experience was significantly higher in nonfluoridated cities (1.38 vs 0.98 in fluoridated cities) and there were more caries-free children in fluoridated cities (56.4% vs 40.6% in nonfluoridated). DMFT was higher in cities with lower socioeconomic status than high socioeconomic status (1.29 vs 1.05, respectively, P < .001) and there were fewer caries-free children in low socioeconomic status cities (44.5% vs 53.0% in high socioeconomic status cities, P < .0001). Almost all the 10.3% of children with signs of fluorosis (scoring at least 1 in the Thylstrup-Fejerskov index), had questionable to mild fluorosis (9.3%). Conclusions: CWF is a cheap, simple method of dental health protection that reaches all socioeconomic levels, and cessation of water fluoridation reduced the health of Israel's children. Clinical significance: Water fluoridation provides substantial caries prevention, by reaching a substantial number of people. The relevance of this work is for policymakers to consider CWF as clinically proven method for reducing health inequalities. [ABSTRACT FROM AUTHOR]

The intensity of global groundwater use rose from 124 m3 per capita in 1950 to 152 m3 in 2021, for a 22.6% rise in the annual per capita use. This rise in global per capita water use reflects rising consumption patterns. The global use of groundwater, which provides between 21% and 30% of the total freshwater annual consumption, will continue to expand due to the sustained population growth projected through most of the 21st century and the important role that groundwater plays in the water-food-energy nexus. The rise in groundwater use, on the other hand, has inflicted adverse impacts in many aquifers, such as land subsidence, sea water intrusion, stream depletion, and deterioration of groundwater-dependent ecosystems, groundwater-quality degradation, and aridification. This paper projects global groundwater use between 2025 and 2050. The projected global annual groundwater withdrawal in 2050 is 1535 km3 (1 km3 = 109 m3 = 810,713 acre-feet). The projected global groundwater depletion, that is, the excess of withdrawal over recharge, in 2050 equals 887 km3, which is about 61% larger than in 2021. This projection signals probable exacerbation of adverse groundwater-withdrawal impacts, which are worsened by climatic trends and the environmental requirement of groundwater flow unless concerted national and international efforts achieve groundwater sustainability.

Abstract: Climate change and the increase of population pose challenges to ensuring suitable water supply in water-scarce regions. This work presents a comparative analysis of the water-supply approaches adopted in Los Angeles, Southeastern Spain, and Sydney. Results show a decrease in per-capita water use in the period 2000–2020, which reflects an improvement in water conservation. Social factors in the domain of hydropolitics and economic efficiency explain the divergence of water policies adopted. The adaptation to water scarcity and growing population in three regions of developed countries located in different continents sheds light on challenges facing the achievement of water security worldwide.

Spatial and temporal patterns of water supply and consumptive water use were analyzed from 475 Detailed Analysis Units by County (DAUCOs) spatial units across California during 2002 through 2016 to evaluate spatial and temporal variability and how it might associate with precipitation variability and other factors. Many, but not all, DAUCOs have relatively low total water supply variability compared to that of state-wide precipitation. Such low variability, in DAUCOs having sufficient diversity of water supply sources, is the result of switching between sources as needed to maintain a reliable total water supply. We used multiple approaches to explore these variations which involved four categories of water supply (local, groundwater, imported, and other) and two categories of water use (agricultural and urban). First, a cluster analysis of the volumetric water balance data identified a small set of clusters having similar magnitudes and proportions of water supply sources and water use—some of them composed of only a few DAUCOs but accounting for a disproportionate amount of the state’s water use. Second, a principal components analysis identified leading modes of anomalous water supply and water use among the 475 DAUCOs, capturing most of the time variation during 2002 to 2016. The most prominent mode exhibits a multi-year trend, most strongly involving increasing groundwater supply and agricultural water use, and decreasing urban water use and imported water supply. Over the study period, trends in both supply and use were pronounced, but differed considerably across California DAUCOs. One predominant subset of DAUCOs grew their agricultural water use with increased groundwater supply; in contrast to a widespread group of DAUCOs which reduced their urban water use. An important result for planners is our finding that variation in precipitation—itself important—is amplified by the human response to water supply availability and regulatory policy.

BackgroundWater, sanitation, and hygiene (WASH) access is critical to public health and human dignity. People who inject drugs (PWID) experience stigma and structural violence that may limit WASH access. Few studies have assessed WASH access, insecurity, and inequities among PWID. We describe WASH access, social and geographic inequalities, and factors associated with WASH insecurity among PWID in the Tijuana-San Diego metropolitan area.MethodsIn this cross-sectional binational study, we interviewed PWID (age 18+) in 2020-2021 about WASH access and insecurity. City of residence (Tijuana/San Diego) and housing status were considered as independent variables to describe key WASH access outcomes and to assess as factors associated with WASH insecurity outcomes. Measures of association between outcomes and independent variables were assessed using log modified-Poisson regression models adjusting for covariates.ResultsOf 586 PWID (202 Tijuana; 384 San Diego), 89% reported basic access to drinking water, 38% had basic hand hygiene, 28% basic sanitation, and 46% access to bathing, and 38% reported recent open defecation. Participants residing in Tijuana reported significantly higher insecurity in accessing basic drinking water (aRR: 1.68, 95%CI: 1.02-2.76), basic hygiene (aRR: 1.45, 95%CI: 1.28-1.64), and bathing (aRR: 1.21, 95%CI: 1.06-1.39) than those living in San Diego. Participants experiencing unsheltered homelessness experienced significantly higher insecurity in accessing basic drinking water (aRR: 2.03, 95%CI: 1.07-3.86), basic sanitation (aRR: 1.68, 95%CI: 1.48, 1.92), bathing (aRR: 1.84, 95%CI: 1.52-2.22), and improved water sources for cleaning wounds (aRR: 3.12, 95%CI: 1.55-6.29) and for preparing drugs (aRR: 2.58, 95%CI: 1.36-4.89) than participants living in permanent housing.ConclusionWASH access among PWID in the Tijuana-San Diego metropolitan area was low by international standards and lower than the national averages in both countries. Homelessness was significantly associated with WASH insecurity in this population. Concentrated efforts are needed to guarantee continuously available WASH services for PWID-especially those who are unsheltered.

Groundwater resources are vital to ecosystems and livelihoods. Excessive groundwater withdrawals can cause groundwater levels to decline1-10, resulting in seawater intrusion11, land subsidence12,13, streamflow depletion14-16 and wells running dry17. However, the global pace and prevalence of local groundwater declines are poorly constrained, because in situ groundwater levels have not been synthesized at the global scale. Here we analyse in situ groundwater-level trends for 170,000 monitoring wells and 1,693 aquifer systems in countries that encompass approximately 75% of global groundwater withdrawals18. We show that rapid groundwater-level declines (>0.5 m year-1) are widespread in the twenty-first century, especially in dry regions with extensive croplands. Critically, we also show that groundwater-level declines have accelerated over the past four decades in 30% of the worlds regional aquifers. This widespread acceleration in groundwater-level deepening highlights an urgent need for more effective measures to address groundwater depletion. Our analysis also reveals specific cases in which depletion trends have reversed following policy changes, managed aquifer recharge and surface-water diversions, demonstrating the potential for depleted aquifer systems to recover.

China's Losses Plateau (LP) is one of the ecologically vulnerable and the most severe soil erosion regions. Thus, knowing spatiotemporal changes in evapotranspiration (ET) and its components (soil evaporation, E; transpiration, T; and vegetation interception evaporation, EI) and revealing the underlying mechanisms are vital for ecosystem and water resources sustainability for this region. Here, we investigate the spatiotemporal changes in ET and its components and then quantify the impacts of climate variables (i.e., precipitation, radiation, temperature, and relative humidity) and vegetation dynamics (e.g., land use/cover changes [LUCC] and changes in leaf area index [LAI]) on their annual trends, by using a process‐based terrestrial ecosystem model and a joint‐solution method with multiple sensitivity numerical experiments. Results show that over 67% of the study region experienced significant (p < 0.05) increases in annual ET, T, and EI, with regional average rises of 4.05, 3.67, and 0.74 mm·year−1, respectively. However, there are significant (p < 0.05) decreases in regional mean E of 0.38 mm·year−1, and the negative trend covers 35.8% of the study area. E, T, and EI changes dominate the annual ET trends over 11.8%, 87.3%, and 0.9% of the study area, respectively. Attribution analyses highlight the increased LAI as the critical factor governing these trends across most of the LP (>58%). At the same time, precipitation and LUCC play a more dominant role in the remaining areas. This study emphasizes the spatial heterogeneity in the drivers of changes in ET and its components and highlights the critical role of vegetation dynamics. These findings provide valuable insights for understanding the ET processes and guiding sustainable water resource management in the LP. [ABSTRACT FROM AUTHOR]

We describe the bias adjustment and downscaling to a resolution of 1 × 1 km of daily temperature, precipitation and solar radiation of a multimodel ensemble of Coupled Model Intercomparison Project Phase 6 (CMIP6) GCMs with the local observational data set BhutanClim for Bhutan and an analysis of the results for 1996–2100. The GCMs were selected based on their ability to reproduce local temporal and spatial precipitation patterns, resulting in a total of 14 models for each shared socioeconomic pathway (SSP). The results are shown for five global warming levels (GWLs) 1.5, 2, 3, 4 and 5°C, providing insight into the projected impacts of climate change at different warming levels. The daily temperature and precipitation data are publicly available, which is of great benefit for climate impact studies, such as ecological, hydrological or infrastructure‐related studies. In this paper, we discuss showcase climate indicators. Peak‐over‐threshold climate indicators such as hot days above 30°C are relevant for human health. In the capital city of Thimphu, these are currently rare, at 4 days per year, but might increase to more than 80 for GWL5.0. Precipitation increases in the summer months, but slightly decreases in the drier winter months. Accordingly, the 3‐month SPEI drought index is projected to increase in summer, but strongly decreases in the winter months, mostly pronounced in February. The increasing severity of late‐winter and spring droughts might have a negative impact on vegetation, wildfires and water supply. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFAS), known colloquially as “forever chemicals,” have been associated with adverse human health effects and have contaminated drinking water supplies across the United States owing to their long-term and widespread use. People in the United States may unknowingly be drinking water that contains PFAS because of a lack of systematic analysis, particularly in domestic water supplies. We present an extreme gradient–boosting model for predicting the occurrence of PFAS in groundwater at the depths of drinking water supply for the conterminous United States. Our model results indicate that 71 million to 95 million people in the conterminous United States potentially rely on groundwater with detectable concentrations of PFAS for their drinking water supplies before any treatment. [ABSTRACT FROM AUTHOR]

Climate change has increased the frequency and severity of weather extremes, including droughts, heat waves and compound drought and heatwave (CDHW) events. CDHW events profoundly impact water availability, agriculture, public health and energy production, particularly in the Horn of Africa (HOA). This study examined the historical spatiotemporal patterns of CDHW periods in the HOA during three periods (1951–1980, 1971–2000 and 1991–2020) using the ERA5 reanalysis dataset. This study utilized monthly Standardized Precipitation Evapotranspiration Index (SPEI) data to detect droughts and daily maximum temperature data to identify heatwaves for characterizing the duration, severity and magnitude of CDHW events. The results show a substantial increase in the duration of CDHW events in recent years, with durations reaching up to 25 days. The average duration of heat waves also increased from 7 days before 1993 to 18 days by 2011, culminating in a record‐breaking 43‐day heat wave in 2019. Most areas experienced a significant increase in heatwave duration by more than 12 days from the early period of 1951–1980 to the late period of 1991–2020. Although around 76% and 69% of the HOA exhibited insignificant heatwave trends in the first two periods, Ethiopia and Kenya experienced substantial increases of more than 18 days during the most recent period, with some durations exceeding 25 days in recent decades. The magnitude of CDHW events generally decreased as drought duration intensified, but specific areas, particularly southwest Kenya and Eritrea, exhibited higher CDHW values in the last period. These findings underscore the urgent need to understand and address CDHW events in the HOA. Targeted interventions for disaster risk reduction and resilience‐building are needed to mitigate the adverse effects of these events in this vulnerable region. This study provides a basis for future research and policy formulation in the HOA. [ABSTRACT FROM AUTHOR]

The Tibetan Plateau (TP), a crucial area influencing global climatic patterns and water resources, is experiencing a unique climatic paradox, particularly evident in the Three Rivers Source Region (TRSR). A striking summer asymmetry in the increases of near-surface temperature and precipitation is observed from 1989 to 2018: the rate of daily minimum temperature (0.64°C decade−1) surpasses the daily maximum temperature (0.52°C decade−1), while the daytime precipitation intensity (0.40 mm day−1 decade−1) increases at a faster rate compared to nighttime (0.30 mm day−1 decade−1). Despite these trends, the summer mean nighttime precipitation intensity consistently remains higher than the daytime average. Notably, this pattern is accompanied by an increasing trend of moisture transport during both daytime and nighttime in TRSR. This paper deciphers the thermodynamic and dynamic processes behind this trend. The daytime warmth not only alters the stability of atmosphere but also modulates convective inhibition (CIN), thereby reshaping precipitation mechanics and potentially dampening or delaying daytime convection. Thermodynamically, a shift from unstable to stable anomalies in the summer troposphere suppresses precipitation development. The combination of increased CIN during those period leads to fewer but more intense rainy days. Dynamically, the shift from a consistent downward motion anomaly throughout troposphere to an upward motion anomaly becomes dominant during nighttime, exhibiting a similar transition but only below 500 hPa during daytime. These findings reveal the complex interplay between thermodynamics, dynamics, and precipitation, highlighting the need for refined climatic models that can accurately simulate these summer diurnal processes. [ABSTRACT FROM AUTHOR]

Inorganic carbon acquisition is essential to algal growth, while the limitations of dissolved inorganic carbon (DIC) on phytoplankton are still less known in lakes. Sediment is an active hot spot for microbial metabolism, driving the migration and transformation of elements in shallow lakes, which may control the DIC availability to influence algal spatiotemporal dynamics. Hence, we investigated the spatiotemporal changes of phytoplankton, DIC and sediment respiration rates in a eutrophic shallow freshwater lake under non-bloom conditions. There was a widespread deficiency of DIC in the lake, except the estuary. Sediment respiration was positively associated with changes in DIC concentrations, indicating that carbon metabolic activity of sedimentary microorganisms was an important inorganic carbon source for water columns. The availability of DIC in water columns regulated by sediment microbial respiration influenced the algal biomass, composition and productivity. The synergistic effects of seasonal temperature changes and sediment microbial respiration influenced the vertical distribution and migration of phytoplankton. Our results emphasized that carbon metabolic intensity of sediment microorganisms might play a key role in dynamics of phytoplankton, further impacting the spatiotemporal pattern and formation of algal bloom in eutrophic shallow freshwater lakes. [ABSTRACT FROM AUTHOR]

The forensic application of stable oxygen isotope data from human tissues depends on naturally occurring isotopic variation in drinking water across geographic areas. One factor which complicates interpretation of forensic data is local variability: if a wide range of drinking water values is in a small geographic region it may be difficult to identify or rule out that region as a location of origin. We examine data from community collection programs documenting tap water isotope variation within 30 cities\developed areas throughout the United States. Isotopic variation within individual developed areas ranged widely, from essentially nil to greater than 9‰ (δ18O interdecile range). Many (14/30) of the study areas exhibited multi-modal isotope distributions, even in cases where the isotopic range was very small (e.g., <2.0‰), suggesting that the use of multiple, isotopically different sources was common. Most variation was attributed to differences in the source-region altitude or degree of evaporation for different water sources, and we observe limited variation in areas where contrasts in these variables are small. Variation tended to be largest in cities across the western USA. We explored correlations between the magnitude of local isotopic variation and climatic, environmental, and socioeconomic variables. We found that higher levels of variation occurred at sites where local water resources were likely to be more isotopically heterogeneous and in lower supply, consistent with the development of supply systems in these areas that access diverse and isotopically heterogeneous water resources. We also found that variation was positively correlated with larger developed areas, suggesting that pressures related to city growth may affect the degree to which infrastructure tapping diverse water resources is developed. Collectively, our results suggest that the influence of local tap water isotope heterogeneity on the precision of forensic geolocation is systematic and somewhat predictable, information to be factored into future applications. [ABSTRACT FROM AUTHOR]

In the Caatinga, a Brazilian dry forest, low water availability is a limiting factor that affects the growth and survival of herbaceous plants. Thus, we hypothesize that simulated extreme changes in precipitation modify aboveground and belowground vegetative responses differently between annual and perennial herbaceous species. Seedlings of the species were obtained through seed germination. During 1 year, they were submitted to three rainfall simulation (RS) treatments, defined from a 60‐year sequence: Twet‐RS of rainy years; Tcontrol‐RS of years close to the historical average; Tdry‐RS of dry years; and with 30 repetitions per treatment. The daily water administration corresponded to the daily average of rainfall in the past. In the simulation of dry years, the annual species reduced the growth drastically, while the perennials showed a moderate reduction. All species reduced biomass and production and expansion of their leaves in dry years but invested in water storage and leaf longevity. Below ground, annuals explored surface water resources and perennials invested in root growth, accessing underground layers. If reductions in rainfall are confirmed, the allocation of herbaceous biomass may follow an “optimal partitioning” strategy, along with maintaining higher water content in the organs, which is an efficient survival strategy. [ABSTRACT FROM AUTHOR]

ABSTRACT Drought limits crop performance worldwide. Plant roots' ability to grow toward moisture, termed hydrotropism, is considered one strategy for optimizing water recruitment from the growth medium. Based on the sequence of the hydrotropism‐indispensable MIZ1 protein in Arabidopsis thaliana, we identify hydrotropism and drought‐responsive genes in tomato. We utilized CRISPR/Cas9 genome‐editing technology for targeted mutagenesis of three hydrotropism‐associated loci (MIZ1‐like) in tomato (Solanum lycopersicum). We show that the three tomato MIZ1‐like genes are drought‐responsive and two of them are hydrostimulation‐responsive. Examination of the root hydrotropic response of triple and double mutants indicated the gene SlMIZ1‐1 as indispensable for tomato root hydrotropism. Moreover, expression of the SlMIZ1‐1 gene in the Arabidopsis miz1 mutant effectively complemented the lost MIZ1 functionality, including root hydrotropic bending and generation of hydrotropic Ca2+ signals. Transcriptome analysis of hydrostimulated tomato root tips under control gravity and continuous clinorotation conditions was performed to identify gravitropism‐ and hydrotropism‐responsive genes. This analysis suggested the involvement of ethylene and ABA signalling in modulating the interplay between hydrotropism and gravitropism. Unveiling the molecular mechanisms that underlie hydrotropism and drought response holds great potential for improving crop performance under limiting water availability due to global climate changes. [ABSTRACT FROM AUTHOR]

High need for precision agriculture today has been associated with the completeness of the data available. The application of smart technology becomes the main alternative for fulfilling incomplete data and predicting future data. This paper presents the results of a research that aims to monitor and to predict water availability for determining conservation strategy on water availability using time series data from satellite rainfall, spanning from 2007 to 2022. We employed the innovative use of remote sensing technology, global rainfall measurement (GPM) and Climate Hazards Group InfraRed Rainfall with Station data (CHIRPS), to assess and correct satellite-derived rainfall estimates against ground-based observations. Conducted in the Serang watershed of Mount Merbabu’s volcanic landscape, the research employs a quantitative descriptive approach. We used coupled climate models MIROC6 and MRI-ESM2-0 in the CMIP-6 Framework for rainfall projections 2023–2030, then continued with the F.J. Mock model simulations for water availability projection. Our findings reveal a significant impact of climate change on water availability over the decade, with the most extreme conditions observed in 2029 and 2030, where the increasing of water availability reaching 10 m3 /s. The results showed that CHIRPS performed well in describing rainfall data. The novelty of this research highlighting the potential of: firstly, the use of satellite rainfall data for this specific region has not been extensively studied before; secondly, the discovered impacts of climate change to the water availability are particularly noteworthy, and thus contributing to the sustainability of agricultural practices in response to climate change. A limitation of this study is the short investigation period of just one decade, which does not fully capture the long-term impacts of climate change. Future research is recommended to utilize satellite data over extended periods to better represent extreme climate events and derive drought and wetness patterns over durations exceeding one decade. [ABSTRACT FROM AUTHOR]

When water resources are limited, cotton (Gossypium hirsutum L.) plants adapt in part through adjustments in carbon allocation strategies, often evident in the leaves within the canopy. The dynamics of leaf carbon accumulation provide insights into how the plant partitions and uses carbon resources, a key aspect of optimizing crop productivity. In this study, we investigated the dynamics of leaf carbon accumulation in two cotton cultivars (Phytogen [PHY] 350 and Stoneville [ST] 5707) across spatial and temporal scales under two different levels of irrigation (low: 178 mm year−1, high: 356 mm year−1) in 2020 and 2021. For each cultivar and irrigation treatment, an increase in leaf mass occurred primarily at the bottom of the canopy early in the season, followed by additional leaf production in the middle of the plant as the season progressed. Irrigation reduction resulted in a canopy with reduced radiation interception, less leaf shading in the lower canopy, and thicker leaves. In contrast, more irrigation created canopies with a larger effective leaf area, increasing total light interception despite increased shading at the canopy base. Additionally, leaf carbon allocation is synchronized with fruit carbon demand at the onset of the first bloom stage for an early‐maturing cultivar. Overall, this study provides valuable insights into the complex relationship between water availability, radiation intensity within the canopy, and leaf carbon dynamics, contributing to a more comprehensive understanding of the plant's overall performance in resource‐constrained environments. [ABSTRACT FROM AUTHOR]

The impact of limited water availability on lettuce growth has been well documented. However, the mechanisms by which lettuce controls seed germination under water stress remain unknown. Germination percentage was evaluated in the cv. Salinas (Lactuca sativa) (L. sativa) × US96UC23 (Lactuca serriola) (L. serriola) recombinant inbred line (RIL) population and USDA germplasm collection using 10% polyethylene glycol (PEG). About 50% of both populations displayed less than 90% germination. The average broad-sense heritability (H2) for germination percentage was 0.81 across both populations. Two quantitative trait loci (QTL) for germination percentage were identified on chromosomes 4 and 8 in the RIL population. The RNA-Seq and network analyses of wild lettuce, US96UC23, were performed using the control (distilled water, dH2O) and treatment (10% PEG) datasets. The number of differentially expressed genes (DEGs) was 4,095. The top 20 gene ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were assessed by enrichment analysis. The consensus network analysis captured 44 modules. Gene networks were constructed for the top 20 hub genes in 10 significant modules from each dataset. This study comprehensively explains QTL, GO terms, KEGG pathways, and gene networks associated with lettuce seed germination under osmotic stress. [ABSTRACT FROM AUTHOR]

Recently, solar‐driven interfacial evaporation (SDIE) has been developed quickly for low‐cost and sustainable seawater desalination, but addressing the conflict between a high evaporation rate and salt rejection during SDIE is still challenging. Here, a spatial confinement strategy is proposed to prepare the gel composite solar evaporator (SCE) by loading one thin hydrogel layer onto the skeleton of a carbon aerogel. The SCE retains the hierarchically porous structure of carbon aerogels with an optimized water supply induced by dual‐driven forces (capillary effects and osmotic pressure) and takes advantage of both aerogels and hydrogels, which can gain energy from air and reduce water enthalpy. The SCE has a high evaporation rate (up to 4.23 kg m−2 h−1 under one sun) and excellent salt rejection performance and can maintain structural integrity after long‐term evaporation even at high salinities. The SDIE behavior, including heat distribution, water transport, and salt ion distribution, is investigated by combining theoretical simulations and experimental results. This work provides new inspiration and a theoretical basis for the development of high‐performance interfacial evaporators. [ABSTRACT FROM AUTHOR]

Summary Leaf architecture impacts the ease of gases diffusion, biochemical process, and photosynthetic performance. For balsam poplar, a widespread North American species, the influence of water availability on leaf anatomy and subsequent photosynthetic performance remains unknown. To address this shortcoming, we characterized the anatomical changes across the leaf profile in three‐dimensional space for saplings subjected to soil drying and rewatering using X‐ray microcomputed tomography. Our hypothesis was that higher abundance of bundle sheet extensions (BSE) minimizes drought‐induced changes in intercellular airspace volume relative to mesophyll volume (i.e. mesophyll porosity, θIAS) and aids recovery by supporting leaf structural integrity. Leaves of ‘Carnduff‐9’ with less abundant BSEs exhibited greater θIAS, higher spongy mesophyll surface area, reduced palisade mesophyll surface area, and less veins compared with ‘Gillam‐5’. Under drought conditions, Carnduff‐9 showed significant changes in θIAS across leaf profile while that was little for ‘Gillam‐5’. Under rewatered conditions, drought‐induced changes in θIAS were fully reversible in ‘Gillam‐5’ but not in ‘Carnduff‐9’. Our data suggest that a ‘robust’ leaf structure with higher abundance of BSEs, reduced θIAS, and relatively large mesophyll surface area provides for improved photosynthetic capacity under drought and supports recovery in leaf architecture after rewatering in balsam poplar. [ABSTRACT FROM AUTHOR]

The implement of water resources spatial equilibrium (WRSE) schemes is fundamental task of integrated water resources management in China, in which, the evaluation and simulation analysis of WRSE system is of great concern for understanding the overall variation and feedback characteristics of WRSE system. Therefore, we utilized the ordered degree, entropy and connection number coupling model to evaluate the variation of WRSE system, and also employed system dynamics (SD) and scenario simulation integrated method to reveal the feedback characteristics between different equilibrium variables and subsystems, and thus the set pair analysis‐SD based approach for structure simulation and variation trend evaluation of WRSE system was constructed. The application results in Anhui province, China demonstrated that, the overall variation of provincial spatial equilibrium situation of WRSE system presented obvious improving trend, 2009–2019, the index of ordered degree and connection number entropy in Hefei, increased from the minimum of 0.6434 (Grade 3, unequilibrium) to maximum of 0.9985 (Grade 1, equilibrium). Moreover, the future variation of WRSE system will display stable improving trend during 2020 to 2029, in which, annual water resources availability and water resources utilization efficiency will have significant influence on WRSE system. And the research findings can be favorable to formulate water resources development and utilization strategies. [ABSTRACT FROM AUTHOR]

Facing the growing challenges in water supply in urban areas, characterized by high demand and water scarcity, Mexico City, with its high population density and limited water resources, exemplifies the challenges in ensuring equitable management and water supply in complex urban environments. This study combines GIS tools, statistical analysis and spatial regression to analyze the spatiotemporal changes in per capita water consumption in Mexico City households between 2010 and 2019. The results show a 40% decrease in average consumption and a spatial reconfiguration that reflects an increase in inequalities in access to drinking water. The influence of five key factors in the reconfiguration is identified: intermittent supply, economic income, water feasibility, households without piped water, and an increase in dwellings. The findings are essential for developing equitable and effective water policies, emphasizing the need to address inequalities in water access in urban planning to achieve the Sustainable Development Goals. [ABSTRACT FROM AUTHOR]

Climate change and human activities alter the global freshwater cycle, causing nonstationary processes as its distribution shifting over time, yet a comprehensive understanding of these changes remains elusive. Here, we develop a remote sensing-informed terrestrial reanalysis and assess the nonstationarity of and interconnections among global water cycle components from 2003 to 2020. We highlight 20 hotspot regions where terrestrial water storage exhibits strong nonstationarity, impacting 35% of the global population and 45% of the area covered by irrigated agriculture. Emerging long-term trends dominate the most often (48.2%), followed by seasonal shifts (32.8%) and changes in extremes (19%). Notably, in mid-latitudes, this encompasses 34% of Asia and 27% of North America. The patterns of nonstationarity and their dominant types differ across other water cycle components, including precipitation, evapotranspiration, runoff, and gross primary production. These differences also manifest uniquely across hotspot regions, illustrating the intricate ways in which each component responds to climate change and human water management. Our findings emphasize the importance of considering nonstationarity when assessing water cycle information toward the development of strategies for sustainable water resource usage, enhancing resilience to extreme events, and effectively addressing other challenges associated with climate change. [ABSTRACT FROM AUTHOR]

Summary The first year in a tree's life is characterized by distinct morphological changes, requiring constant adjustments of the hydraulic system. Despite their importance for the natural regeneration of forests and future vegetation composition, little has been known about the hydraulics of tree seedlings. At different times across the first growing season, we analysed xylem area‐specific (Kshoot_Axyl) and leaf area‐specific (Kshoot_L) shoot hydraulic conductance, as well as embolism resistance of three temperate conifer trees, two angiosperm trees and one angiosperm shrub, and related findings to cell osmotic parameters and xylem anatomical traits. Over the first 10 wk after germination, Kshoot_Axyl and Kshoot_L sharply decreased, then remained stable until the end of the growing season. Embolism resistance was remarkably low in the youngest stages but, coupled with an increase in cell wall reinforcement, significantly increased towards autumn. Contemporaneously, water potential at turgor loss and osmotic potential at saturation decreased. Independent of lineage, species and growth form, the transition from primary to secondary xylem resulted in a less efficient but increasingly more embolism‐resistant hydraulic system, enabling stable water supply under increasing risk for low water potentials. [ABSTRACT FROM AUTHOR]

ABSTRACT It has been broadly reported that future climate change will most likely affect the spatio‐temporal distribution of water resources and consequently droughts. There is a prevailing notion that an increase in temperature and frequency of heat waves are expected to result in more intense droughts in the coming years. In this study, we aimed to evaluate the effect of the potential evapotranspiration (PET) method selection on future drought projections over Poland. In our study, simulations of the Soil and Water Assessment Tool (SWAT) model were conducted, utilising an ensemble of six EURO‐CORDEX projections, spanning the period from 2006 to 2100 under the RCP8.5 scenario. Two model setups with two different PET methods (Penman‐Monteith—PM and Hargreaves—HAR) were used. For drought conditions evaluation we selected the Standardized Precipitation Index (SPI) and Standardized Precipitation‐Evapotranspiration Index (SPEI) for meteorological drought, Standardized Streamflow Index (SSI) for hydrological drought, and Standardized Soil Moisture Index (SMI) for agricultural drought. The meteorological and hydrological droughts were calculated using a 12‐month time aggregation window, while agricultural drought was calculated using a 3‐month window. Climate projections revealed that by 2080s annual mean temperature and precipitation increase is expected by up to +3.4°C and +10.3% respectively. Under future climate conditions duration and severity of meteorological droughts are projected to decrease. PM method leads to a higher PET increases (1.35 mm year−1) than the HAR method (1.1 mm year−1) throughout the century which entail diverging signal of change for agricultural and hydrological droughts. PM‐ and HAR‐based simulations indicate increase in the total duration and cumulative severity of agricultural droughts, buthowever, for HAR‐based projections, the increase is much less. For hydrological droughts the signal of change is similar for both PET methods, but considerably distinct in magnitude. Considering the entire simulation period, by the end of the century cumulative severity of hydrological droughts is projected to decrease, with a much more pronounced decline for HAR (70% reduction) than for the PM method (35% reduction). Our study demonstrated that methodological choices are crucial to the assessment of future drought risk under climate change. [ABSTRACT FROM AUTHOR]

Low organic matter content is one of the main constraints in arid and semiarid regions. This constraint and its negative influences on soils and plant growth may be alleviated by biochar (BC). Furthermore, improving soil physical and hydraulic attributes by application of biochar has received increased attention. Therefore, in the present study, the effects of sugarcane bagasse-derived biochar on the structural stability, water availability, and pore-size distribution (PSD) of three texturally different calcareous soils collected from different agro-climatologically regions were examined during a long-term experiment. Low and high-temperature biochars, produced in a muffle furnace by the traditional slow pyrolysis method at 300 °C (BC300) and 600 °C (BC600) were evaluated. Pots (15 kg) were filled with three different silty-clay Inceptisols (SCInc), silty-clay-loam Alfisols (SCLAlf), and loam Aridisols (LArid) soils mixed with 0 (control), 1, 2, and 3 w/w% of BC300 and BC600 during 540 days of incubation. The high energy moisture characteristic (HEMC) data was modeled using a modified van Genuchten function to quantify aggregate stability through stability ratio (SR) and structural stability index (SSI). The plant available water (PAW), least limiting water range (LLWR), and integral water capacity (IWC) were calculated with two matric suctions (h) of 330 cm for field capacity (FC) and 15,000 cm for permanent wilting point (PWP). Then the integral energy (EI) values were calculated (EIIWC). Results indicated that the incorporation of 3 w/w% biochar significantly (p < 0.01) increased SR (35 to 100%) and SSI (21 to 28%) indices in all three soils. Biochar significantly increased modal suction (MS) in LArid soils (5 to 158%); whereas, decreased MS of the other soils (3 to 43%). MS, SR, and SSI of BC300 and BC600-treated soils were not significantly different. PAW, LLWR, and IWC significantly decreased in the SCInc (18 to 61%, 8 to 44%, and 6 to 35%) and SCLAlf (8 to 44%, 18 to 35%, and 20 to 47%) soils and increased in LArid (4 to 54%, 3 to 61%, and 24 to 111%) soil with increasing biochar doses. There were no changes in EIIWC in biochar-treated LArid soil where PAW, LLWR, and IWC increased. Biochar increased EIIWC across the studied soil from 1% to 3.38 folds, thereby increasing the gradient of water potential to absorb the available water. Soil and soil-biochar mixtures exhibited heterogeneous and multimodal pore-size distribution (PSD). Biochar promoted the PSD peaks related to water-transmitting pores in SCInc and SCLAlf soils while decreased in LArid soil. In conclusion, results indicated that among the applied levels of biochar, the application of 3 w/w% biochar is suggested as a suitable way to improve soil physical behavior and structural stability. [ABSTRACT FROM AUTHOR]

VegDischarge v1, which covers over 64,000 river segments in Africa, is a natural river discharge dataset produced by coupled modeling; the agro-hydrologic VegET model and the mizuRoute routing model for the period 2001-2021. Using remote sensing data and hydrological modeling system, the 1-km runoff field simulated by VegET, was routed with mizuRoute. Performance metrics show strong model reliability, with R² of 0.5–0.9, NSE of 0.6–0.9, and KGE of 0.5–0.8 at the continental scale. The total average annual discharge for Africa is quantified at 3271.4 km³·year−1, with contributions to oceanic basins: 1000.0 km³·year−1 to the North Atlantic, primarily from the Senegal, Gambia, Volta, and Niger Rivers; 1327.2 km³·year−1 to the South Atlantic, largely from the Congo River; 214.7 km³·year−1 to the Mediterranean Sea, predominantly from the Nile River; and 729.4 km³·year−1 to the Indian Ocean, with inputs from rivers such as the Zambezi. The dataset is valuable for stakeholders and researchers to understand water availability, its temporal and spatial variations that affect water-related infrastructure planning, sustainable resource allocation, and the development of climate resilience strategies. [ABSTRACT FROM AUTHOR]

The direct utilization of solar energy for the artificial photosynthesis of hydrogen peroxide (H2O2) provides a reliable approach for producing this high-value green oxidant. Here we report on the utility of high-entropy oxide (HEO) semiconductor as an all-in-one photocatalyst for visible light-driven H2O2 production directly from H2O and atmospheric O2 without the need of any additional cocatalysts or sacrificial agents. This high-entropy photocatalyst contains eight earth-abundant metal elements (Ti/V/Cr/Nb/Mo/W/Al/Cu) homogeneously arranged within a single rutile phase, and the intrinsic chemical complexity along with the presence of a high density of oxygen vacancies endow high-entropy photocatalyst with distinct broadband light harvesting capability. An efficient H2O2 production rate with an apparent quantum yield of 38.8% at 550 nm can be achieved. The high-entropy photocatalyst can be readily assembled into floating artificial leaves for sustained on-site production of H2O2 from open water resources under natural sunlight irradiation. An "all-in-one" high-entropy semiconductor photocatalyst enables the photocatalytic production of H2O2 from H2O and O2 under visible light without any external cocatalysts or sacrificial agents [ABSTRACT FROM AUTHOR]

Evaporative cooling is being re‐evaluated in the context of eco‐systems and environmental friendliness to improve the efficiency of thermoelectric and photovoltaic power generation. One of the essential tasks to improve evaporative cooling performance is the development of materials that can maintain the evaporation path and supply the lost water. Here, we synthesized a macroporous hydrogel by freeze casting at a slow cooling rate. A series of open spaces was designed between the aligned columns of the hydrogel, and water is stably supplied by extensive capillary channels. In a cooling test, it was shown to be effective in reducing the target's equilibrium temperature. As the heat input increased, the cooling effect (that is, the temperature reduction by the hydrogels) tended to increase. In addition, under airflow, the effect was stable, and further enhanced. These results extend design strategies for hydrogel‐based evaporative cooling and offer opportunities to maximize cooling performance by searching for optimal surface shape and exploiting airflow conditions. [ABSTRACT FROM AUTHOR]

Limited water availability, population growth, and increasing water demand have resulted in freshwater crises in many countries, including China. In this paper, the water resource‐carrying capacity (WRCC) model simulated the trajectory of China's various systems, representing interactions among humans, water resources, and economics, among others. The results indicated that, at the national level, 700 billion m3 of available freshwater could support population sizes of 2.12, 1.96, and 1.85 billion, along with economic sizes of $40.65, $34.08, and $29.21 trillion, under high‐, moderate‐, and low‐development scenarios, respectively. And it also showed the population and economic size of each province across China under high‐, moderate‐, and low‐development scenarios. This study's WRCC‐based simulations can provide guidance for future policies related to water, population, and economics. Overall, contributions of this study include (1) a quantitative model related to freshwater security and water policies; (2) the model narratives that paint a better picture of China's future water security and socioeconomic development; (3) the conclusion that it is conducive to adjust water use rigid constraints with water policies; (4) an understanding that it is more intuitive to use population size and economic scale instead of dimensionless scores to characterize the state of WRCC. The WRCC model is instructive for the other counties or regions. [ABSTRACT FROM AUTHOR]

Integrating photovoltaic power stations into large-capacity hydropower stations is an efficient and promising method for regulating large-scale photovoltaic power generation. However, constrained by the time step length, traditional long-term scheduling of hydro-PV hybrid systems does not adequately consider short-term operational performance indicators, resulting in sub-optimal scheduling plans that fail to coordinate the consumption of photovoltaic power and the utilization of water resources in the basin. To address this, this study established a long-term optimal scheduling model for hydro-PV hybrid systems. This model overcomes the limitation of the time step length in long-term scheduling by incorporating long-term power generation goals and short-term operation performance targets into the long-term optimal scheduling process based on scheduling auxiliary functions. In case studies, the optimised model balanced the long-term power-generation goals and short-term operational performance targets by redistributing energy across different periods. Compared to optimization models that did not consider short-term operation performance, in a typical normal year, the model effectively reduced the electricity curtailment volume (28.54%) and power shortage volume (10.91%) of the hybrid system while increasing on-grid electricity (0.03%). Similar improvements were observed in wet and dry years. These findings provide decision support for hydropower scheduling in the context of large-scale photovoltaic power integration. [ABSTRACT FROM AUTHOR]

Extracting water information from remote-sensing images is of great research significance for applications such as water resource protection and flood monitoring. Current water extraction methods aggregated richer multi-level features to enhance the output results. In fact, there is a difference in the requirements for the water body and the water boundary. Indiscriminate multi-feature fusion can lead to perturbation and competition of information between these two types of features during the optimization. Consequently, models cannot accurately locate the internal vacancies within the water body with the external boundary. Therefore, this paper proposes a water feature extraction network with spatial partitioning and feature decoupling. To ensure that the water features are extracted with deep semantic features and stable spatial information before decoupling, we first design a chunked multi-scale feature aggregation module (CMFAM) to construct a context path for obtaining deep semantic information. Then, an information interaction module (IIM) is designed to exchange information between two spatial paths with two fixed resolution intervals and the two paths through. During decoding, a feature decoupling module (FDM) is developed to utilize internal flow prediction to acquire the main body features, and erasing techniques are employed to obtain boundary features. Therefore, the deep features of the water body and the detailed boundary information are supplemented, strengthening the decoupled body and boundary features. Furthermore, the integrated expansion recoupling module (IERM) module is designed for the recoupling stage. The IERM expands the water body and boundary features using expansion and adaptively compensates the transition region between the water body and boundary through information guidance. Finally, multi-level constraints are combined to realize the supervision of the decoupled features. Thus, the water body and boundaries can be extracted more accurately. A comparative validation analysis is conducted on the public datasets, including the gaofen image dataset (GID) and the gaofen2020 challenge dataset (GF2020). By comparing with seven SOTAs, the results show that the proposed method achieves the best results, with IOUs of 91.22 and 78.93, especially in the localization of water bodies and boundaries. By applying the proposed method in different scenarios, the results show the stable capability of the proposed method for extracting water with various shapes and areas. [ABSTRACT FROM AUTHOR]

Microalgae have long been regarded as a promising solution for biological carbon abatement from the power industry, offering renewable biomass without competing for land or water resources used for food crops. In this study, we extensively examined the application of photosynthetic microorganisms for closing carbon, nitrogen, and micronutrient loops in the power industry. Subsequently, we explored the bottom-up integration of algal biorefineries into power industry waste streams for increased economic benefits and reduced environmental impacts. Analysis of the available data indicated that microalgae integration with the power industry is primarily performed using flue-gas-assisted cultivation. This approach allows for carbon sequestration typically below one gram per liter per day, too low to significantly impact carbon abatement at achievable scales of microalgae cultivation. Alternative approaches are also being explored. For example, soluble bicarbonate platforms allow for higher biomass productivity and temporary carbon storage. Meanwhile, the use of ashes and waste heat and thermophilic strains can result in lower cultivation costs and better control of cultivation conditions. These approaches offer further incremental improvement to microalgae-based carbon abatement systems in the power industry but are unlikely to be an umbrella solution for carbon reduction. Consequently, in the near term, microalgae-based carbon valorization systems are likely to be limited to niche applications involving the synthesis of high-value products. For microalgae to truly transform carbon abatement processes radical improvements in both biology and engineering approaches are urgently needed. [ABSTRACT FROM AUTHOR]

Mountain ecosystems play an important role globally as centers of biodiversity and in providing ecosystem services to lowland populations, but are influenced by multiple global change drivers such as climate change, nitrogen deposition, or altered disturbance regimes. As global change is accelerating and the consequences for humans and nature are intensifying, there is an increasing demand for understanding and predicting the impacts and implications of global change on mountain ecosystems. Manipulation experiments are one of the major tools for testing the causal impacts of global change and establishing a mechanistic understanding of how these changes may transform the global biota from single organisms to entire ecosystems. Over the past three decades, hundreds of such experiments have been conducted in mountainous regions worldwide. To strengthen the experimental evidence for the possible ecological consequences of global change, we systematically reviewed the literature on global change experiments in mountains. We first investigated the spread of manipulation experiments to test the effects of different global change drivers on key biological and ecological processes from the organism to the ecosystem level. We then examined and discussed the balance of evidence regarding the impact of these global change drivers on biological and ecological processes, and outlined the possible consequences for mountain ecosystems. Finally, we identified research gaps and proposed future directions for global change research in mountain environments. Among the major drivers, temperature was manipulated most frequently, generally showing consistent strong impacts between biological and ecosystem processes, functional groups, and habitat types. There is also strong evidence suggesting that changes in water and nutrient availability have a direct impact on the life history and functioning of mountain organisms. Despite these important findings, there are several gaps that require urgent attention. These include experiments testing adult trees in tropical and boreal regions, assessing animal responses and biotic interactions, and investigating aquatic environments and soil systems more extensively. A broader approach that integrates experimental data with field observations and relies on international collaboration through coordinated experiments could help address these gaps and provide a more consistent and robust picture of the impacts of global change on mountain ecosystems. [ABSTRACT FROM AUTHOR]

Energy transitions are reshaping hydrosocial relations. How they will be reshaped, however, depends on location and water's material relationship to other resources and industrial activities embedded within energy transitions. To highlight this, we focus on three different resources—coal, natural gas, and lithium—to signal how the water–energy nexus will be reworked in a transition away from fossil fuels. We examine the water–coal nexus as an example of a resource relationship that is transitioning out, or that is being moved away from in the green energy transition. Natural gas represents the "bridge fuel" used through the transition. Lithium illustrates a resource inside the green transition, as it is a fundamental material for green technologies in the transition to a low‐carbon future. Coal, natural gas, and lithium each have their own material impacts to water resources that stem from their industrial lifecycle and different implications for communities shaped by coal, natural gas, and lithium activities. To explore this, we review each of these resources' connection to water, their legal and regulatory dimensions, and their impact on communities and water justice. We argue that the energy transition is also a hydrosocial transition that will create uneven water‐related benefits and burdens. To maximize sustainability and equity, efforts to decarbonize energy systems must examine the localized, place‐based hydrosocial relations that differentially affect communities. This article is categorized under:Engineering Water > Planning WaterHuman Water > Water GovernanceHuman Water > Rights to Water [ABSTRACT FROM AUTHOR]

Together with other "bottom‐up" methods, climate stress testing is becoming a prominent approach for climate change impact assessment of water systems. Compared with traditional approaches, stress testing is: (i) more focused on exploring the vulnerabilities of the system at hand; (ii) potentially more inclusive, being amenable to stakeholder involvement and (iii) well suited to identify robust policy options that better account for the deep uncertainty associated with multiple plausible futures. Stress testing is rapidly evolving and giving rise to new techniques and concepts, but few articles provide an accessible overview that can serve as an introduction to the field. Here, we review the underlying principles and concepts of climate stress testing, providing a guide to the main decisions involved in practical application. Topics include selection of stressors, characterizing and exploring the exposure space and data generation including the use of stochastic data. In a complex world where water decisions are made in the context of wider socio‐ecological systems, stress testing and other bottom‐up methods can support decisions that are not only robust to future uncertainty but also regarded as legitimate by affected communities. This article is categorized under:Engineering Water > Sustainable Engineering of WaterScience of Water > Water and Environmental ChangeWater and Life > Stresses and Pressures on Ecosystems [ABSTRACT FROM AUTHOR]

• Carbon isotope composition (δ13C) variation among J. curcas genotypes is discrete. • Drought-induced changes in δ13C is remarkable in J. curcas. • δ13C may be used as a tool for screening water-use efficient genotypes in J. curcas. Jatropha curcas L. is a non-food crop quoted as a promising natural feedstock for biodiesel production in tropical and subtropical regions. Although an efficient mechanism of drought avoidance through stomatal control of transpiration has been demonstrated in this species, low carbon assimilation and growth rates preclude any advantage of such strategy under water limitation. Two greenhouse experiments were conducted with the objective of investigating varietal differences in water use as the trade-off between carbon isotope composition (δ13C) in different tissues and water use efficiency, in young plants of J. curcas. The first experiment was a survey with seven provenances of J. curcas under non-limiting water availability. There were no significant differences among provenances for leaf gas exchange rates, growth and whole-plant transpiration (T). However, significant effects of provenance and tissue (stem bark or leaf) in δ13C were demonstrated. The provenances CNPAE183 and CNPAE222 were selected for the second experiment, as variations in water use traits and δ13C between the two provenances were observed. Soil water deficit, imposed for 18 days, led to significant physiological, biochemical, and morphological changes. An early and sharp response to water deficit in CNPAE183 as compared to CNPAE222 was observed, as indicated by a 44% higher rate of decrease of T in the former. In addition, water deficit led to increase of δ13C, which was more pronounced in CNPAE222 (13% in young leaves) when compared to CNPAE183 (11% in young leaves). In both provenances, δ13C was less negative in young as compared to mature tissues. Significant and direct correlations between stem bark and leaf δ13C and leaf-level intrinsic water use efficiency were observed. Contrasting results, particularly on T and δ13C, suggest the existence of genetic diversity for water relations and metabolic traits linked to drought tolerance in J. curcas. Using stem bark or leaf δ13C measurements as the basis for large-scale screening of water-use efficient genotypes should be considered. [ABSTRACT FROM AUTHOR]

The energy transition necessitates hydrogen generation to meet current energy needs. Low-carbon hydrogen (green hydrogen from renewable energy, and blue hydrogen from gas with CO2 removal and storage) is touted as a replacement, with most authors recognising the 'green' credentials of hydrogen. However, this paper examines the impact of hydrogen generation on water resources in the driest inhabited country on Earth – Australia. After analysing water use, the paper then undertakes a detailed analysis of the Australian Certificate of Origin Scheme. The paper concludes that competition over water will need to be considered in both project approvals and certification schemes. [ABSTRACT FROM AUTHOR]

Fernandez, P.N.J.; Fernandez, E.G.B.; Cadondon, J.G., and Subade, R.F., 2024. Enhancing coastal management through the design and development of an in situ water quality monitoring system. Journal of Coastal Research, 40(6), 1090–1102. Charlotte (North Carolina), ISSN 0749-0208. The Philippines, with its extensive coastline rich in water resources, faces challenges because of the heavy reliance of residents on coastal waters for recreation and livelihood. This leads to water quality deterioration. Balancing human development with environmental protection necessitates regular, close monitoring of water resources. Traditional methods of water quality analysis are time-consuming and labor-intensive, and regular monitoring is financially burdensome. This study introduces the design and development of a customized water quality monitoring device as an alternative to traditional laboratory analysis. The device is portable, user-friendly, and capable of rapidly gathering real-time data. It features a multiparameter sensor that simultaneously measures temperature, pH, dissolved oxygen (DO), and electrical conductivity (EC). After testing and calibration, the device showed a mean error of 0.91°C for temperature, –0.025 mg/L for DO, 0.09 for pH, and 0.033 mS/cm for EC. Forty seawater samples from nine Environmental Management Bureau coastline monitoring stations were analyzed using the device. Comparison with commercially available in situ devices showed a moderate coefficient of determination for DO and pH and a high coefficient of determination for EC and temperature, indicating that some environmental and user-related factors affect readings. Insights from empirical results and consultations with local stakeholders will inform future improvements of the device. Implementing this prototype can help to inform decisions on resource management, pollution control, and public health protection. Real-time data can aid in early detection of contaminants and pollution sources, which allows swift remedial action, and adaptive management practices. [ABSTRACT FROM AUTHOR]

Drought is a natural disaster characterised as precipitation much lower than the precipitation reported in actual periods. Many studies characterized drought as meteorological, hydrological, agricultural, or socioeconomic. When there is a long-term shortage of precipitation, deficits in surface and ground waters occur. In this study, a hydrological drought analysis has been performed for Wadi Mina Basin (4900 km2), which is the biggest sub-basin in Cheliff Basin, using the Streamflow Drought Index (SDI) for the time scales of 3, 6, 9, and 12-month. Monthly mean streamflow records for 05 stations are obtained from the National Water Resources Agency. The obtained SDI values were subjected to Run analysis and drought duration and severity values were calculated. According to the analysis, it has been observed that the maximum (duration: 70 months, severity: 92.78) and average (duration: 31 months, severity: 31.28) droughts occurred at the Sidi AEK Djillali station on a 12-month time scale. The average drought severity was 6.34, with a maximum value of 56.71 on a monthly time scale. However, on a 12-month time scale, the average drought severity increased to 31.28, with a maximum value of 92.78. Therefore, it can be said that the drought severity has increased with the increase in the time scale. When the temporal changes of drought indices are evaluated, it is noteworthy that extraordinary droughts prevailed in the basin in 2000 and 2007. When the scatter diagrams of drought characteristics were examined, it was seen that there was a significant linear relationship between drought duration and severity. In addition, the highest correlation was observed at the 9-month time scale at Ain Hamara (R:0.964) and Oued Abtal (R:0.904) stations. In contrast, the highest correlation was observed at the 12-month time scale at Sidi AEK Djillali (R:0.980) and Takhmaret (R:0.969) stations. [ABSTRACT FROM AUTHOR]

The presence of uranium in groundwater has become a growing concern due to its potential health implications. This abstract focuses on the assessment of uranium concentrations in groundwater samples collected from the Kangra district. The study employed rigorous sampling and analysis techniques to evaluate the extent of uranium contamination and its distribution in the groundwater resources of the region. A comprehensive survey was conducted across various locations within the Kangra district, involving the collection of groundwater samples from different depths and geological formations. The collected samples were subjected to meticulous laboratory analysis, employing advanced spectroscopic method of LED fluorimeter to quantify uranium concentrations. The findings reveal varying levels of uranium in the groundwater samples, with concentrations ranging from minimal to elevated levels. The distribution of uranium was observed to be influenced by geological factors, hydrological characteristics, and anthropogenic activities. This research contributes to the understanding of little uranium contamination in the Kangra district's groundwater, serving as a valuable resource for policymakers, researchers, and stakeholders striving to ensure the safety and sustainability of the region's water resources. [ABSTRACT FROM AUTHOR]

E. coli and total coliforms are the most widely used indicator organisms for microbial monitoring of drinking water and recreational freshwater. In many remote and low-resource settings, however, conventional laboratory methods for quantifying these indicators are challenging or infeasible to perform due to limited access to laboratory facilities. The availability of rapid, low-cost methods for quantifying indicator organisms in freshwater samples without the need for laboratory facilities is crucial to facilitate the rapid and robust monitoring of microbial water quality in these types of settings. The global misuse and abuse of antimicrobials have contributed to the rise of antimicrobial resistance. Thus, simple culture methods are needed to detect indicators of such bacteria in freshwaters. In 2021, the World Health Organization released the Tricycle protocol to address this issue by providing guidance for culture-based detection of extended-spectrum beta-lactamase (ESBL)-producing E. coli in environmental samples. Our research goal was to compare the 100-ml sample volume ESBL E. coli quantal and enumerative commercial tests against the more complex Tricycle protocol to detect and quantify ESBL E. coli in surface waters. Both commercial tests gave results comparable with the results obtained using the Tricycle protocol, and the quantal and enumerative commercial tests were easier and faster to perform than the Tricycle protocol. [ABSTRACT FROM AUTHOR]

The article discusses the progress in models for coupled human and natural systems, highlighting the reciprocal interaction between humans and the environment. It explores the importance of modeling CHANS in supporting sustainable development and understanding the dynamic complexity of these systems. The text also addresses challenges in studying CHANS, such as bidirectional feedback, deep integration of natural and social sciences, multiscale simulation, and transformative improvement in simulation speed. The article emphasizes the need for adaptive algorithms, integration methods, and quantum computing to enhance decision support and achieve sustainable development goals. [Extracted from the article]

The presence of highly toxic dioxins, specifically polychlorinated dibenzo-p-dioxins (PCDDs), in drinking water is a matter of great concern due to their long-lasting nature and harmful effects. In this study, we detected three out of the five dioxin congeners: 2, 3, 7, 8-tetrachlorodibenzodioxin (TCDD), 1, 2, 3, 7, 8-pentachlorodibenzo-p-dioxin (PeCDD), and octachlorodibenzo-p-dioxin (OCDD). The investigation revealed that three dioxins were present in water samples of winter season, while TCDD and OCDD were found in the summer season. The geometric mean concentrations of PCDDs were 229.9 ng/L (winter) and 108.4 ng/L (summer), exceeded the maximum contaminant level of 30 pg/L set by the USEPA in surface water. The estimated daily intake of PCDDs for residents through drinking water was 273.97 ng-WHO2005-TEQ/kg/days during winter and 78.875 ng-WHO2005-TEQ/kg/days during summer. Our study emphasizes the urgent need for further research on persistent organic pollutants in drinking water to safeguard public health and community well-being. [ABSTRACT FROM AUTHOR]