Future Water Availability Research Articles

Prioritizing water availability study settings to address geogenic contaminants and related societal factors

Water availability for human and ecological uses depends on both water quantity and water quality. The U.S. Geological Survey (USGS) is developing strategies for prioritizing regional-scale and watershed basin-scale studies of water availability across the nation. Previous USGS ranking processes for basin-scale studies incorporated primarily water quantity factors but are now considering additional water quality factors. This study presents a ranking based on the potential impacts of geogenic constituents on water quality and consideration of societal factors related to water quality. High-concentration geogenic constituents, including trace elements and radionuclides, are among the most prevalent contaminants limiting water availability in the USA and globally. Geogenic constituents commonly occur in groundwater because of subsurface water–rock interactions, and their distributions are controlled by complex geochemical processes. Geogenic constituent mobility can also be affected by human activities (e.g., mining, energy production, irrigation, and pumping). Societal factors and relations to drinking water sources and water quality information are often overlooked when evaluating research priorities. Sociodemographic characteristics, data gaps resulting from historical data-collection disparities, and infrastructure condition/age are examples of factors to consider regarding environmental justice. This paper presents approaches for ranking and prioritizing potential basin-scale study areas across the contiguous USA by considering a suite of conventional physical and geochemical variables related to geogenic constituents, with and without considering variables related to societal factors. Simultaneous consideration of societal and conventional factors could provide decision makers with more diverse, interdisciplinary tools to increase equity and reduce bias in prioritizing focused research areas and future water availability studies.

Evaluating future water availability in Texas through the lens of a data-driven approach leveraged with CMIP6 general circulation models

Climate change is escalating the frequency and intensity of extreme precipitation events, significantly influencing the spatial and temporal distributions of water resources. This is particularly evident in Texas, a rapidly growing state with a pronounced west-east gradient in water supply. This study utilizes Coupled Model Intercomparison Project Phase 6 (CMIP6) data and data-driven methodology to improve projections of Texas's future water resources, focusing on actual evapotranspiration (AET) and water availability through enhanced Multi-Model Ensembles. The results reveal that the data-driven model significantly outperforms the CMIP5 and CMIP6 models across all skill metrics, underscoring the potential of data-driven methodologies in advancing climate science. Furthermore, the study provides an in-depth analysis of the projected changes in net water availability (NWA) and estimated water demand for different regions in Texas over the next six decades from 2015 to 2074, which reveal fluctuating patterns of water stress, with the regions (nine out of sixteen water planning regions in Texas, especially for the most populated regions) poised for heightened challenges in reconciling water demand and availability. While increasing trends are found in precipitation, AET, and NWA for the northern region of Texas based on SSP2–4.5, decreasing trends are found over the southern region for all three parameters based on SSP5–8.5. These findings underscore the importance of factoring both spatial and temporal variations in water availability and demand for effective water management strategies and the need for adaptive water management strategies for the changing water availability scenarios.

Statistical downscaling of high-resolution precipitation in India using convolutional long short-term memory networks

Abstract Statistical downscaling of the General Circulation Model (GCM) simulations are widely used for accessing climate changes in the future at different spatiotemporal scales. This study proposes a novel Statistical Downscaling (SD) model established on the Convolutional Long Short-Term Memory (ConvLSTM) Network. The methodology is applied to obtain future projection of rainfall at 0.25° spatial resolution over the Indian sub-continental region. The traditional multisite downscaling models typically perform downscaling on a single homogeneous rainfall zone, predicting rainfall at only one grid point in a single model run. The proposed model captures spatiotemporal dependencies in multisite local rainfall and predicts rainfall for the entire zone in a single model run. The study proposes a Shared ConvLSTM model providing a single end-to-end supervised model for predicting the future precipitation for entire India. The model captures the regional variability in rainfall better than a region-wise trained model. The projected future rainfall for different scenarios of climate change reveals an overall increase in the rainfall mean and spatially non-uniform changes in future rainfall extremes over India. The results highlight the importance of conducting in-depth hydrologic studies for different river basins of the country for future water availability assessment and making water resource policies.

Does ERA5-land capture the changes in the terrestrial hydrological cycle across the globe?

Changes in the terrestrial hydrological cycle determine the future water availability across the globe with profound impacts in different facets of society. Precise estimation of such changes is vital for the effective implementation of water management policies. Among the numerous data products that describe the hydrological cycle components, ERA5-Land is one of the most increasingly used dataset. Still, there has been no assessment of its ability capacity to represent the water cycle shifts variability over land. This study endeavors to bridge this gap by comparing the magnitude and direction of change in precipitation minus evaporation (P—E) and runoff, as estimated globally by the ERA5-Land data product. Our findings reveal significant inconsistencies in the changes identified, with the climatological mean of P—E decreasing more substantially than runoff for numerous regions. Consequently, ERA5 presents a declining water availability for most of the regions, but the magnitude of change is incompatible to the change between P—E and runoff. To further validate, the estimates provided by the ERA5-Land product, two different hydrologic models (TerraClimate and Global Land Data Assimilation System, GLDAS-Noah) are also utilized. TerraClimate demonstrates a more reasonable alignment between changes in P—E and runoff, followed by GLDAS-Noah, particularly for the arid regions lying in the parts of Northern Africa and Southern Asia, the European continent, and the northern parts of Asia. Inconsistencies remain high for the tropical regions for both data products. Still, the estimates of change in water availability are better represented by the hydrologic model-based data sources for most parts of the globe, especially for the regions with low precipitation, such as the regions with arid and continental climates. Our results imply that ERA5-Land should be used with extreme caution when assessing the long-term changes in the terrestrial water cycle. Additionally, pinpointing the regions of the highest bias can help to improve the hydrological coupling of ERA5-Land in future versions of the reanalysis.

Implications of uncontrolled water withdrawal and climate change on the water supply and demand gap in the Lake Tana sub-basin

This study evaluates the implications of multiple climatic and non-climatic factors on the water resource of the Lake Tana sub-basin, Ethiopia. The study focuses on three drivers: land use change, irrigation expansion, and climate change (CC), and their impact on the current and future water availability across the sub-basin. The study uses a random forest (RF) machine learning classifier in the Google Earth Engine (GEE) platform to detect land use land cover change (LULC) and for mapping the actual irrigated-area. The Climate Hazards Group InfraRed Precipitation and temperature data were used with station data to evaluate the implication of CC on the water availability of Lake Tana sub-basin. The supply-demand relationship was done for Gumara catchment within Tana sub-basin as an experimental site. Based on the LULC analysis, plantation, cropland, bare lands, built-up, and wetland showed an increasing trend, while forest, bush land, and grassland showed a decreasing trend. The increasing rate of crop land in the expense of natural forest, shrub land, grassland may cause runoff/flood, high soil erosion, and lower rate of groundwater recharge. The actual irrigated area mapping analysis shows a widespread irrigation near the Lake Shore and upstream parts of the sub-basin. The climate change analysis shows an increasing trend of potential evapotranspiration during the irrigation period attributed to increase in maximum temperature. The rising of potential evapotranspiration during the irrigation period creates a water shortage in the study and future periods as the crops need more water for growth. The estimated stream flow for Gumara catchment shows an increasing trend for the future period. The supply-demand relationship of the catchment shows an uneven distribution of water in the Gumara catchment both in the current and future periods resulting in unbalance abstraction of irrigation water. The study reveals that climate change, land cover change, and uncontrolled expansion of irrigated land area are likely to increase the unmet demand by increasing irrigation water demand, and this can cause conflict of interest between the users. Therefore, sustainable water resource management practices such as land management practices, and adaptive management of irrigation should be applicable to prevent or reduce the occurrence of conflict over the water demand.

Modeling root zone water and salt transport using matric flux potential based root water uptake distribution

It is important to delineate the root water uptake (RWU) response to salt and water stress for assessing future water availability under extreme climatic conditions. The process of RWU in salt-affected soils is highly complex and not well understood. The present study proposed a matric flux potential based non-linear RWU model capable of calculating reduced RWU in water and salt stressed conditions. The study incorporates a sensitivity analysis of the model's parameters. For the inverse estimation of these parameters, an objective function has been formulated, utilizing data derived from the highly sensitive model's response. The proposed objective function provides unique estimates for these parameters. Using this objective function in an optimization process, the model is calibrated with observed data obtained from a soil column lysimeter experiment conducted on berseem crop (Trifolium alexandrium). The parameters are optimized through the coupling of the model with a genetic algorithm-based optimizer tool. Simulated data for soil moisture, electrical conductivity, and percolation are then compared to observed data. The simulated model's responses are found to be closely aligns with the experimentally observed values. The RWU under four irrigation of different salinity levels is simulated. The results highlight a reduction in RWU compensation under high-salinity irrigation treatment.

Study of changes in temporal distribution pattern of rainfall at Dapoli station in Konkan region of Maharashtra

Dapoli situated in the Konkan region of Maharashtra is having average annual rainfall of 3587 mm with average number of rainy days 75. The yield of major Kharif season crop rice is affected by the erratic behavior of rainfall. Present study is an attempt to study the rainfall variations at the Dapoli station which will be useful for forecasting the future temporal availability of water. Comprehensive statistical tools were used to investigate trends in averages and monthly rainfall over the station on decadal basis. Forty years (year 1972-2011) daily rainfall data for Dapoli station was used for the analysis. Results of study showed that, decadal mean rainfall depths of June and August were found decreasing and those for September was found increasing. Mean rainfall depth variations for July as well as annual total rainfall were found random. Seven years moving averages showed that, rainfall depths for the months of June, July and August were found decreasing and for month of September was found increasing. In annual rainfall graph a slight decline was observed.

Larger increase in future global terrestrial water availability than projected by CMIP6 models

<p>Climate change and increasing water use associated with socio-economic growth have exacerbated the water crisis in most of the world. However, terrestrial water availability (precipitation minus evapotranspiration, PME) is inadequately represented within Earth System Models, directly affecting the reliability and consistency of future projections. To address this issue, we employ twenty Coupled Model Intercomparison Project Phase 6 (CMIP6) models and multiple observational PME datasets to produce more robust future projections. Most models underestimate the increase in PME over 1982–2011, while over 80% of the models project a continued rise in future PME. We thus constrain future changes in global mean PME (ΔPME) under medium and high greenhouse gas emission scenarios (SSP2-4.5 and SSP5-8.5) using the hierarchical emergent constraint (HEC) approach. The constrained PME shows a significant increase by 33.81 ± 13.72mm, or 13% ± 5%, during the period <styled-content style-type="number">2070</styled-content>–<styled-content style-type="number">2099</styled-content> relative to 1982–2011 under SSP5-8.5. Implementation of the HEC method reduces the uncertainty range by 24% and shows the ΔPME of the raw CMIP6 was underestimated by 37%. The PME change trends are most evident in low-latitude regions, with constrained PME increasing by 75.69 ± 24.35 mm, or 28% ± 9%, in the Northern Hemisphere’s low latitudes and by 34.56 ± 38.91mm, or 8% ± 10% in the Southern Hemisphere’s low latitudes by <styled-content style-type="number">2070</styled-content>–<styled-content style-type="number">2099</styled-content> under SSP5-8.5. Our findings highlight the importance of accurate model representation of precipitation to produce reliable projections of global terrestrial water availability. The observationally-constrained ΔPME is valuable for sustainable management of water resources.</p>

Analysis of runoff variations in an arid catchment based on multi-model ensemble- a case study in the Tarim River Basin in Central Asia

Runoff variation is of significant importance to the current and future water availability of a region, particularly in arid regions, and plays a crucial role in economic and social development. The Tarim River Basin, spanning an area of approximately 102 × 104 km2, is the largest inland river basin in China. Due to the basin’s extremely dry climate, water shortage is the most critical natural factor restricting socio-economic development in the region. This study focuses on analyzing the historical and future runoff changes of the four headstreams (the Kaidu, Aksu, Yarkand, and Hotan rivers) in the Tarim River Basin with historical observations and multiple-model projections. The results indicate that the runoff of the Tarim’s four headstreams showed an increasing trend during 1957–2022, with a remarkable increment of 40.70 × 108 m3, or 18% in percentage. Rising temperatures and precipitation are the main reasons for the runoff’s increase. Higher temperature accelerates the melting of glaciers, leading to enhanced recharge of meltwater, while more precipitation also boosts the increase in river runoff. Based on the modelling results from the extended SWAT (Soil and Water Assessment Tool), the runoff in the Kaidu, Aksu, Yarkand, and Hotan rivers will remain at a high level in the near future (−2035), with an average increase of 3.2%–7.55%. In the mid 21st century (2036–2065), the runoff of the Yarkand and Hotan River originated from the Kunlun and Karakoram mountains is expected to continue increasing by around 6.25%–15.2%. Under SSP126, the tipping point of glacier melt runoff in the basin may happen by 2058, while under SSP370 and SSP585 scenarios, it may be around 2080. The timing of peak water aligns with projections in the mountainous Asia, but is later compared to the tropical Andes, Western Canada, and the Swiss Alps, whose peak water has already been reached. The results of this study can provide a scientific basis for the allocation and efficient utilization of water resources in the Tarim River Basin and offer valuable insights into the forthcoming runoff changes in mountainous regions.

Understanding the vulnerability of surface–groundwater interactions to climate change: insights from a Bavarian Forest headwater catchment

Headwaters play a crucial role in maintaining forest biodiversity by providing unique habitats and are important for the regulation of water temperature and oxygen levels for downstream river networks. Approximately 90% of the total length of streams globally originate from headwaters and these systems are discussed to be especially vulnerable to impacts of climate change. This study uses an integrated hydrological model (HydroGeoSphere) in combination with 23 downscaled ensemble members from representative concentration pathways (RCPs) 2.6, 4.5 and 8.5 to examine how climate change affects water availability in a headwater catchment under baseflow conditions. The simulations consistently predict increasing water deficits in summer and autumn for both the near (2021–2050) and far future (2071–2099). Annual mean water deficits were estimated to be 4 to 7 times higher than historical levels. This is mainly due to a projected reduction in precipitation inputs of up to – 22%, while AET rates remain similar to those observed during the historical reference period (1992–2018). The declining groundwater storage reserves within the catchment are expected to result in a significant decline in surface water availability during summer and autumn, with a reduction in mean annual stream discharge by up to 34% compared to the reference period. Due to declining groundwater levels, upstream reaches are predicted to become intermittent in summer leading to a reduction of the total stream flow length by up to 200 m. Findings from this study will enhance our understanding of future water availability in headwater systems and may aid in the development of effective management strategies for mitigating local impacts of climate change and preserving these vulnerable ecosystems.

Combining Hydrological Modeling and Regional Climate Projections to Assess the Climate Change Impact on the Water Resources of Dam Reservoirs

Climate change may significantly impact the availability and quality of water resources in dam reservoirs by potentially altering the hydrological regime of lake tributaries and the corresponding flow–duration curves. Hydrological models driven by climate projections (downscaled to the watershed scale and bias corrected to eliminate systematic errors) are effective tools for assessing this potential impact. To assess the uncertainty in future water resource availability, resulting from the inherent uncertainty in climate model projections, an ensemble of climate models and different climate scenarios can be considered. The reliability and effectiveness of this approach were illustrated by analyzing the potential impact of climate change on the water availability at Brugneto Lake in northern Italy. This analysis was based on climate projections derived from an ensemble of 13 combinations of General Circulation Models and Regional Climate Models under two distinct scenarios (RCP4.5 and RCP8.5). The semi-distributed HEC-HMS model was adopted to simulate the hydrological response of the basin upstream of the lake. The hydrological model parameters were calibrated automatically via the PEST software package using the inflows to the lake, estimated through a reverse level pool routing method, as observed values. Future water availability was predicted for short- (2010–2039), medium- (2040–2069), and long-term (2070–2099) periods. The results indicate that the uncertainty in reservoir inflow is primarily due to the uncertainty in future rainfall. A moderate reduction in water availability is expected for Brugneto Lake by the end of the current century, accompanied by modifications in the flow regime. These changes should be considered when planning future adaptation measures and adjusting reservoir management rules.

Quantification of climate change-driven water stress on thermal power plants in India

The objective of this work is to quantify the effect of climate change on the intra-annual water stress experienced by thermal power plants in India. The Integrated Environmental Control Model (IECM v11.5) is used to quantify the monthly water withdrawal and consumption for thermal power plants in four different water-stressed states of India. Current water withdrawal range was 2400–5500 l/MWh, and increased during the summer months by as much as 24 % compared to winter months. Simulations for two representative climate change scenarios, namely SSP2 – RCP 4.5 and SSP5 – RCP 8.5, showed 7–18 % increase in water withdrawal as compared to the present. For the state of Rajasthan, future surface water availability, estimated using Budyko's framework, decreased by more than 49 % for both scenarios as compared to present. Power plants in regions analysed will face water deficits during January-May, necessitating careful planning to manage climate change impacts in the future.

Farm dam accounting for healthy and safe agricultural catchments

ABSTRACT Farm dams are essential infrastructure for many farming operations, including livestock watering and crop irrigation. With demand for food increasing, many farmers are looking to capture, store and use more runoff to achieve higher yields under worsening climate extremes. The aim of this article is to advance understanding of farm dams in catchments and the current tools for accounting for them, providing an opportunity to consider a new runoff storage accounting framework to support integrated policy. The Australian dam management setting is provided for context. A longitudinal cohort survey of 254 South Australian farmers provides a snapshot of farmer perceptions of dams and dam management behaviours. Farmers express increasing concern about the future availability of water, how much is allocated to the environment and how this is accounted for. Whilst the field of IWRM and others have integrated disciplines for improved water decision-making, so far there has been limited attention to how to incentivise improved farm dam management through links to farm accounting and business. This study proposes a preliminary framework for assisting dam decision-making across scales to support the health and safety of environments and communities.

Climate Variability and Glacier Evolution at Selected Sites Across the World: Past Trends and Future Projections

AbstractThe availability of freshwater from glaciers and snowmelt is of vital importance for people and ecosystems in the context of global climate change. Here, we focus on 25 glaciers located in different climates and latitudes and investigate their recent (1958–2020) and future projected trends (2020–2050 and 2070–2100) in monthly precipitation (Pr), maximum and minimum temperatures, ice mass loss, and their relationships with cloud properties. The study sites are located in Temperate Europe (France), the Inner (Ecuador, Venezuela, and Colombia) and Outer Tropics (Bolivia and Peru), Central America (Mexico), tropical Southeast Asia (Indonesia), Equatorial Africa (Uganda), and the Southern dry and Patagonian Andes (Chile and Argentina). The climate analyses are based on TerraClimate data (Monthly Climate and Climatic Water Balance for Global Terrestrial Surfaces) and 28 CORDEX (Coordinated Regional Climate Downscaling Experiment) climate simulations. Our findings reveal that, extrapolating current glacier volume change trends, almost half of the studied glaciers are likely to vanish (95%–100% volume loss) by 2050, with widespread warming and drying trends since 1958. A shift toward wetter conditions at Pico Humboldt (Venezuela) and Martial Este (Argentina) identifiable in the CORDEX simulation will very likely not have a limiting impact on glacier mass loss owing to increasing temperatures, which will raise the elevation of the rain/snow limit. Our results provide useful new information to better understand glacier‐climate relationships and future scenarios dominated by ice mass loss trends across the globe. These findings suggest serious consequences for future water availability, which exacerbate the vulnerability of local populations and ecosystems.

Analysing the elevation-distributed hydro-climatic regime of the snow covered and glacierised Hunza Basin in the upper Indus

In the high altitude Hindukush Karakoram Himalaya (HKH) mountains, the complex weather system, inaccessible terrain and sparse measurements make the elevation-distributed precipitation and temperature among the most significant unknowns. The elevation-distributed snow and glacier dynamics in the HKH region are also little known, leading to serious concerns about the current and future water availability and management. The Hunza Basin in the HKH region is a scarcely monitored, and snow- and glacier-dominated part of the Upper Indus Basin (UIB). The current study investigates the elevation-distributed hydrological regime in the Hunza Basin. The Distance Distribution Dynamics (DDD) model, with a degree day and an energy balance approach for simulating glacial melt, is forced with precipitation derived from two global datasets (ERA5-Land and JRA-55). The mean annual precipitation for 1997–2010 is estimated as 947 and 1,322 mm by ERA5-Land and JRA-55, respectively. The elevation-distributed precipitation estimates showed that the basin receives more precipitation at lower elevations. The daily river flow is well simulated, with KGE ranging between 0.84 and 0.88 and NSE between 0.80 and 0.82. The flow regime in the basin is dominated by glacier melt (45%–48%), followed by snowmelt (30%–34%) and rainfall (21%–23%). The simulated snow cover area (SCA) is in good agreement with the MODIS satellite-derived SCA. The elevation-distributed glacier melt simulation suggested that the glacial melt is highest at the lower elevations, with a maximum in the elevation 3,218–3,755 masl (14%–21% of total melt). The findings improve the understanding of the local hydrology by providing helpful information about the elevation-distributed meltwater contributions, water balance and hydro-climatic regimes. The simulation showed that the DDD model reproduces the hydrological processes satisfactorily for such a data-scarce basin.

Potential Impacts of Climate Change on the Al Abila Dam in the Western Desert of Iraq

The potential impacts resulting from climate change will cause significant global problems, particularly in underdeveloped nations where the effects are felt the most. Techniques for harvesting water such as small dams provide an alternative supply of water and are adaptive solutions to deal with water scarcity in the context of future climate change. However, it is difficult to determine how rainwater harvesting (dams) may be impacted by climate change since general circulation models (GCMs), widely utilized for predicting potential future climate change scenarios, work on an extremely large scale. The primary aim of this research was to quantify the effect of climate change on water availability at the catchment scale by statistically downscaling temperature and rainfall from the GCMs. Then, using a water harvesting model, the performance of the Abila Dam in Iraq’s western desert was evaluated in both the current climate (1990–2020) and various future climate change scenarios (2020–2100). Precipitation generally decreases as the annual temperature increases. To simulate future water availability, these changes in meteorological factors were incorporated into the water harvesting model. In total, 15% or less of net storage might fulfil the whole storage capacity during the baseline period, whereas it is 10% in RCP 2.6 in 2011–2040 for future scenarios. In contrast, RCP 8.5 will be able to meet water needs at a pace of 6% in 2011–2040. The findings of this study proved that the Al Abila dam will be unable to supply the necessary water for the area surrounding the Al Abila dam in the future scenarios.

Availability of clean water and discharge reliable for housing taman argo subur cisoka, tangerang district

The problem of water availability is an important issue in the development of a residential area, because the availability of water resources is the supporting capacity for the development of a residential area. Adequate water availability for now and predictions of future water availability are very important to know for ensuring an area that is feasible for development. The purpose of this study is to determine the amount of water availability through the method of calculating the water balance and calculating the mainstay discharge to find out whether the water needs are fulfilled or not. Household water consumption is one of the biggest contributors to the water crisis in residential areas. For this reason, it is necessary to have information that has high accuracy regarding the existence of water sources and the amount of water reserves owned by a location. The water balance is one way to determine the availability of water in an area so that it can be calculated whether the location will experience a water crisis or not. Calculation of water balance using the FJ Mock method can provide the information needed whether an area has a surplus of water or not and can be used to calculate the mainstay discharge which is useful for distributing water to residents. Making reservoirs or tendons is an alternative to overcome the occurrence of a water crisis when the dry season comes because often residential areas experience water shortage problems. For this reason, a calculation is made regarding the amount of water debit produced by the water reservoir made by the manager and the amount of surplus water is based on the monthly average method. The results of the calculation of the FJ Mock discharge can be seen that the resulting maximum discharge is 0.504 m3/second and the minimum discharge is 0.069 m3 / sec. The results of the reliable discharge calculation show that the water discharge is still acceptable or meets the criteria because even though in August the water discharge that was achieved was only 0.069 m3/sec, this amount still meets the requirements at a reliability value of 99% and at an error value of 1%. These results provide evidence that the discharge generated by the two residential tendons of Taman Argo Subur still meets the requirements.

Estimation of the impact of combined sewer overflows on surface water quality in a sparsely monitored area

Combined sewer overflows (CSOs) can have a severe negative, local impact on surface water systems. To assure good ecological surface water quality and drinking water production that meets the demands, the impact of sewer system overflows on the surrounding water bodies for current and future climate conditions needs to be assessed. Typically, integrated, detailed hydrological and hydrodynamic water quantity and quality models are used for this purpose, but often data and computational resource requirements limit their applicability. Therefore, an alternative computationally efficient, integrated water quantity and quality model of sewer systems and their receiving surface waters is proposed to assess the impact of CSOs on surface water quality in a sparsely observed area. A conceptual model approach to estimate CSO discharges is combined with an empirical model for estimating CSO pollutant concentrations based on waste water treatment plant influent observations. Both methods are compared with observations and independent results of established reference methods as to evaluate their performance. The methodology is demonstrated by modelling the current impact of CSOs on the water abstraction area of a major drinking water production centre in Flanders, Belgium. It is concluded that the proposed conceptual models achieve similar results for daily WWTP effluent and CSO frequency, whereby the accumulated CSO volume is similar to more detailed full hydrodynamic models. Further, the estimated pollutant concentrations correspond with another dataset based on high resolution sampled overflows. As a result, the proposed computational efficient method can give insights in the impact of CSOs on the water quality at a catchment level and can be used for planning monitoring campaigns or performing analyses of e.g. the current and future water availability for a data scarce areas.

Irrigation benefits outweigh costs in more US croplands by mid-century

Irrigation can increase crop yields and could be a key climate adaptation strategy. However, future water availability is uncertain. Here we explore the economic costs and benefits of existing and expanded irrigation of maize and soybean throughout the United States. We examine both middle and end of the 21st-century conditions under future climates that span the range of projections. By mid-century we find an expansion in the area where the benefits of irrigation outweigh groundwater pumping and equipment ownership costs. Increased crop water demands limit the region where maize could be sustainably irrigated, but sustainably irrigated soybean is likely feasible throughout regions of the midwestern and southeastern United States. Shifting incentives for installing and maintaining irrigation equipment could place additional challenges on resource availability. It will be important for decision makers to understand and account for local water demand and availability when developing policies guiding irrigation installation and use.

Threat of non-metallic mining on the integrity of the Tocuyo River basin, Lara state, Venezuela

There are various conflicts of usage in the Tokuyo River Basin of Lala Prefecture. The contradiction is that in a semi-arid and water scarce area, the soil has many natural resources, among which the most prominent are non-metallic minerals ((NMM), such as silica, the best clay and a series of decorative stones in the country. The public policies of the State and local governments prevail in this territory. They encourage NMM mining, therefore, criticism of an extractivist economy that has historically dominated the country arises. Through an exhaustive documentary review, results show that there are few references to environmental impact studies associated with NMM mining. There is evidence of open-pit mining near rivers and streams, which exposes areas to erosion and sediment production due to the typical erratic rains that affect the Tocuyo, Morere, Diquiva and Curarigua rivers. The promotion of mining activities by economic interests without the independent participation of environmental institutions puts the integrity of the basin at risk. The situation requires the activism of social movements to denounce the impacts that put, among other things, the future availability of water for human consumption and food production at risk.