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Groundwater availability has become a global challenge due to climatic droughts and human interventions. North India has emerged as one of the most groundwater-depleted regions. Our study delves into the linkage between groundwater variability, climatic and anthropogenic factors for the last two decades using the Gravity Recovery and Climate Experiment (GRACE) and GRACE-Follow On (GRACE-FO) observations, groundwater levels, climatic and socioeconomic datasets. Our novel spatiotemporal analysis of groundwater storage (GWS) anomaly reveals five episodes of notable changes in north India affected by rainfall variability and groundwater abstraction. The standardized precipitation index (SPI) reveals that the prolonged drought and groundwater pumping during 2015 to 2017 significantly affected GWS. Our results suggest that sufficient rainfall contributed to the replenishment of GWS in some zones during 2018 to 2023, likely due to government recharge programmes. Our findings elucidate the current scenario and underscore a pressing necessity to accelerate groundwater management strategies, ensuring its resilience in future periods of intense drought. [ABSTRACT FROM AUTHOR]

This study presents a new holistic framework for modeling farmer decisionmaking by integrating both top-down and bottom-up approaches. It uses three interlinked subsystems to evaluate how changes in water policies impact farmer decisions and profits: the first model simulates water balance, the second simulates farmer behavior, and the third assesses farmer profits. Two scenarios are explored: Scenario I introduces penalties for groundwater overexploitation, and Scenario II implements awareness raising and training to encourage using modern irrigation systems. The results show that penalties lead to reductions in water requests exceeding limits by 8%, 45%, and 68% for fines of 1000, 5000, and 10,000 IRR·m-3, with corresponding net profit decreases of 1.3%, 8.0%, and 11.6%. The ranges of farmer cooperation for groundwater management vary from 20% to 50% over the 10-year simulation period. In Scenario II, increasing the radius of awareness from 0.5 to 2 km substantially increases the adoption of modern irrigation from 1457 to 2057 farmers. These findings highlight how different policy measures impact various types of farmer based on their specific characteristics and preferences. [ABSTRACT FROM AUTHOR]

The Meskiana Plain, in the extreme northeast of Algeria, has experienced distinct climatic periods over the last few decades, ranging from wet to dry and balanced climates. Understanding these climate variations is crucial, especially considering the region's dependence on groundwater for various purposes, including drinking water supply, agriculture and industrial needs. The delicate balance between aquifer recharge and human-induced withdrawals has significant implications for the Meskiana water table. This study aims to comprehensively investigate the interplay between climate variability, groundwater recharge, and human activities to provide valuable insights for sustainable water resource management. The primary objective of this research is to assess the impact of rainfall variability, drought occurrences, and groundwater withdrawals on the Meskiana water table. The overarching goal is to contribute to informed decision-making for sustainable water resource management in this semi-arid region to provide a holistic understanding of the complex interactions shaping the groundwater dynamics in the area. Our findings reveal a delicate balance between climate variability and human activities, particularly groundwater withdrawals. The water table has experienced a substantial drop (up to 66 m), indicating the vulnerability of the region's groundwater resources to drought events and overexploitation. This study underscores the importance of considering both natural and anthropogenic factors in water resource planning for semi-arid regions, providing valuable insights for policymakers, water resource managers, and stakeholders involved in ensuring the long-term sustainability of the Meskiana water table. [ABSTRACT FROM AUTHOR]

Groundwater depletion due to overextraction poses a significant challenge in arid and semiarid rural regions, leading to heightened vulnerability to water scarcity. A comprehensive study of groundwater potential is crucial to employing effective and efficient technologies to address this issue. In this research, groundwater potential zones (GPZs) were generated for the semiarid Anantapur district using an integrated approach of a geographic information system (GIS) and multicriteria decision analysis (MCDA). Three MCDA models—analytical hierarchical process (AHP), best worst method (BWM), and full consistency M-method (FUCOM)—were applied to obtain GPZs by considering 20 groundwater influencing factors for a realistic analysis. A relationship assessment between variables and consistency tests were conducted before evaluating the GPZs to ensure high prediction accuracy. Subsequently, the GPZs were evaluated in the GIS environment using efficient MCDA techniques. The highest prediction accuracy was achieved by FUCOM at 80.6%, followed by BWM at 70.4% and AHP at 63.0%. The best of the three models, FUCOM, reveals that only 0.10% of the district was classified as having high GPZs, whereas 65.49% and 34.41% were classified as medium and low potential areas, respectively. For a better understanding of the contribution of various topographical, hydrological, geological, land use, and proximity parameters toward groundwater potential, map removal and single parameter sensitivity analysis were performed. The results highlighted the efficiency and reliability of geospatial modeling using MCDA techniques when evaluating groundwater potential and understanding the influence of various parameters. This study emphasizes the importance of employing GIS and MCDA methods for assessing groundwater potential in water scarcity regions. The findings provide valuable insights for sustainable groundwater management and resource planning in arid and semiarid regions. [ABSTRACT FROM AUTHOR]

Pakistan's diverse landscapes and agrarian economy heavily rely on its water resources; however, groundwater scarcity poses a pressing challenge, particularly in the context of agriculture, industry, and households. Groundwater is the predominant water source that faces critical fluctuations influenced by seasonal precipitation changes and agricultural acts. Using Gravity Recovery and Climate Experiment (GRACE) based terrestrial water storage anomalies (TWSA), and water storage components from the Global Land Data Assimilation System (GLDAS), significant variations in groundwater storage are revealed. The analysis uncovers uneven groundwater storage patterns across the country, with distinct trends observed in different provinces. Over the past decade, at the national level, groundwater storage has significantly declined, Punjab showed notable decreases in groundwater storage attributed to overexploitation and rising water consumption; Balochistan, Khyber Pakhtunkhwa, Gilgit Baltistan, and Kashmir have declining trends, and Sindh experienced slightly higher levels of groundwater storage due to flood events. Furthermore, analyses showed that floods have led to substantial increases in storage, impacting all provinces, while droughts have caused significant drops in groundwater storage. These findings underscore the importance of sustainable groundwater management acts and emphasize the importance of provincial strategies and autonomy in developing integrated water resource management approaches, aligning with the country's National Water Policy. [ABSTRACT FROM AUTHOR]

Artificial Intelligence (AI), including models like ChatGPT, is transforming water resources management by improving hydrological modeling, water quality assessment, and flood prediction. AI techniques such as Artificial Neural Networks (ANNs) and Support Vector Machines (SVMs) have enhanced streamflow predictions and groundwater management, particularly in data-scarce regions. AI-powered systems like Smart Microclimate Control Systems (SMCS) optimize agricultural practices, leading to better resource conservation and higher crop yields. However, the scalability and applicability of AI across diverse environments pose challenges, especially where data is limited. The success of AI models depends on data quality, requiring ongoing interdisciplinary research to refine these technologies for real-world use. Additionally, tools like ChatGPT, while valuable for knowledge dissemination and data analysis, raise concerns about accuracy in critical decision-making contexts. In conclusion, while AI offers significant potential for improving water resources management, addressing challenges related to data quality, model scalability, and interdisciplinary collaboration is essential for achieving sustainable and effective outcomes. [ABSTRACT FROM AUTHOR]

Based on reasonable management of vegetation in arid area, we consider the effect of artificial irrigation and proposed a vegetation management model with seasonal rainfall and groundwater diffusion. In this work, we describe the relationship between vegetation and groundwater by impulsive differential equation. Sufficient conditions are derived to ensure global asymptotic stability of the vegetation-extinction boundary periodic solution. Sufficient conditions are also derived to examine the permanence of the investigated system. Besides, the correctness of our results is further verified through numerical simulations. These results show that artificial irrigation and groundwater diffusion have a positive effect on the survival of vegetation in arid area. [ABSTRACT FROM AUTHOR]

The shortage in surface water quantities led to a shift in dependence on the groundwater as an alternative water source in southern parts of Iraq. The groundwater is decreasing in quantity and water quality is degrading due to different factors. Therefore, it is important to assess the groundwater quality of the Missan Governorate of the country by analyzing the physicochemical parameters and distinguishing the probable sources of contaminants in the area. The present study used water quality diagrams and statistical methods such as factor analysis and agglomerative cluster analysis to determine the sources of chemical ions in the forty-four groundwater samples collected from wells in the study area. In addition, the Water Quality Index (WQI) was calculated to evaluate the groundwater quality by combining the parameters into a single index. The WQI results varied from − 66.27 to 1064.13 indicating that the groundwater is unsuitable for drinking at various places and good in quality at most of the wells of the area. The main factors that contribute to the differences in the groundwater quality include the variation in geological materials, influence of climate such as the high rate of evaporation, and anthropogenic factors such as industrial activities in central areas such as oil production in the Bazergan oil field. The most affected wells by the petroleum industry that were clustering in cluster R1which show high levels in most water chemistries. The results have implications for the management of the groundwater resources, which are expected to be under more risk of contamination in near future. [ABSTRACT FROM AUTHOR]

This study examines the combined effects of decommissioning lignite mining operations and long-term climate trends on groundwater systems and land surface movements in the Konin region of Poland, which is characterised by extensive open-pit lignite extraction. The findings reveal subsidence rates ranging from −26 to 14 mm per year within mining zones, while land uplift of a few millimetres per year occurred in closed mining areas between 2015 and 2022. Groundwater levels in shallow Quaternary and deeper Paleogene–Neogene aquifers have declined significantly, with drops of up to 26 m observed near active mining, particularly between 2009 and 2019. A smaller groundwater decline of around a few metres was observed outside areas influenced by mining. Meteorological data show an average annual temperature of 8.9 °C from 1991 to 2023, with a clear warming trend of 0.0050 °C per year since 2009. Although precipitation patterns show a slight increase from 512 mm to 520 mm, a shift towards drier conditions has emerged since 2009, characterised by more frequent dry spells. These climatic trends, combined with mining activities, highlight the need for adaptive groundwater management strategies. Future research should focus on enhanced monitoring of groundwater recovery and sustainable practices in post-mining landscapes. [ABSTRACT FROM AUTHOR]

Groundwater is a critical resource that supports agriculture and ecosystems which is increasingly threatened by anthropogenic activities and climate change. Despite the advancements in spatial analysis methods, there remains a lack of comprehensive reviews that synthesize these techniques specifically for groundwater vulnerability assessment as existing literature often focuses on isolated methodologies without integrating them into a cohesive framework that addresses the complexities of groundwater systems. Hence, the need for proactive conservation and mitigation strategies on how spatial analysis can enhance groundwater vulnerability assessments is crucial for developing effective policies and practices aimed at safeguarding this vital resource. This review evaluates various spatial analysis techniques used in assessing groundwater vulnerability, identify their strengths and limitations, and propose a strategic framework for their application in conservation efforts. A systematic literature review was conducted, focusing on peer-reviewed articles published in the last two decades. Techniques such as remote sensing (RS), Geographic Information Systems (GIS), Multi-Criteria Decision Analysis (MCDA), and statistical modelling were analyzed in terms of their applicability to groundwater vulnerability assessments. The findings reveal that spatial analysis techniques significantly enhance the accuracy of groundwater vulnerability assessments (GVAs) by incorporating diverse data sources such as land use, soil characteristics, and hydrological features. Key results indicate that GIS-based models provide robust frameworks for identifying vulnerable areas, while MCDA facilitates stakeholder engagement by integrating socio-economic factors into decision-making processes. The study concludes that a strategic approach combining various spatial analysis techniques offers a promising pathway for enhancing groundwater vulnerability assessments. This integrated methodology not only aids in identifying vulnerable areas but also supports informed decision-making processes regarding conservation efforts. However, future research should focus on developing standardized protocols for integrating diverse spatial analysis methods as well as longitudinal studies to assess the long-term effectiveness of implemented conservation strategies based on these assessments. [ABSTRACT FROM AUTHOR]

Groundwater depletion in arid regions poses a significant threat to agricultural sustainability and rural livelihoods. This study employs geospatial analysis and economic modeling to address groundwater depletion in the arid Barind region of Northwest Bangladesh, where 84% of the rural population depends on agriculture. Using remote sensing and GIS, we developed an elevation map revealing areas up to 60 m above sea level, exacerbating evaporation and aquifer dryness. Field data collected through Participatory Rural Appraisal tools showed farmers exhibiting "ignorant myopic" behavior, prioritizing short-term profits over resource conservation. To address this, an Increasing Block Tariff (IBT) water pricing model was developed, dividing water usage into three blocks based on irrigation hours: 1–275 h, 276–550 h, and 551+ h. The proposed IBT model significantly increases water prices across the three blocks: 117 BDT/hour for the first block (from current 100–110 BDT/hour), 120 BDT/hour for the second block, and 138 BDT/hour for the third block. A demand function (y = −0.1178x + 241.8) was formulated to evaluate the model's impact. The results show potential reductions in groundwater consumption: 59 h in the first block, 26 h in the second block, and 158 h in the third block. These reductions align with the principles of integrated water resource management (IWRM): social equity, economic efficiency, and environmental integration. The model incorporates economic externalities (e.g., well lifting costs) and environmental externalities (e.g., crop pattern shifts), with total costs reaching 92,709,049 BDT for environmental factors. This research provides a framework for sustainable groundwater management in arid regions, potentially reducing overextraction while maintaining agricultural productivity. The proposed IBT model offers a locally driven solution to balance resource conservation with the livelihood needs of farming communities in the Barind tract. By combining remote sensing, GIS, and economic modeling, this research provides a framework for sustainable groundwater management in arid regions, demonstrating the power of geospatial technologies in addressing complex water resource challenges. [ABSTRACT FROM AUTHOR]

We analyze the variation in groundwater budget by modeling an aquifer in a semi-arid region in southern Italy, using different good pumping scenarios. This aquifer is overexploited due to the agricultural vocation of the area. We propose an integrated method to assess the distribution of hydrogeological parameters and the recharge rates. The hydrogeological parametrization is performed through a hydrostratigraphic approach using the geostatistical tool. Recharge rates are computed through a soil water balance application, using different monitoring stations over the area for the whole period of interest. Integrating the results of this analysis with pumping scenarios based on the water irrigation requirement of the main crops in the area, different water budgets are estimated. The results show how different pumping scenarios affect the availability of water resources and thus underline the importance of management. This integrated hydrogeological model can be applied to other areas with similar hydrogeological characteristics, and it can be considered a valuable tool for evaluating sustainable groundwater management strategies, considering land use practices and socio-economic factors. [ABSTRACT FROM AUTHOR]

The combined effect of climate change and increased water demand has put significant strain on groundwater resources globally. Managed aquifer recharge (MAR) has become an effective approach for addressing groundwater depletion problems and sustainable management of groundwater resources. This review article provides an extensive insight into the existing knowledge of MAR, including the main objectives and applications, implementation techniques (surface spreading, sub-surface, and induced recharge) being practiced over the years, risks and challenges associated with the MAR, and the developments in the field of MAR. This review also explores the potential of MAR in the Friuli Venezia Giulia (FVG) region, north-eastern Italy. An average increase in temperature and a decrease in precipitation and piezometric levels in the region suggest the development of a proper MAR plan to manage water resources in the decades to come. Additionally, a comparative analysis of studies published over the last 20 years, focusing on the quantitative and qualitative aspects of water resource management, is conducted to analyze the research trends in the field of MAR. The reviewed literature reveals a notable research trend towards the quantitative aspect compared to the qualitative one. This review also identifies a notable disparity in qualitative studies during the analysis of water quality parameters considered in different MAR studies. Based on this review, a prospective viewpoint to address the challenges and expand the scope of the field is presented. This calls for an optimized strategy that considers both water quality and quantity issues, along with incorporating environmental and socio-economic aspects within the framework of MAR. [ABSTRACT FROM AUTHOR]

Groundwater is essential for drinking water and economic development, yet its availability and quality are threatened by climate change, pollution, and rising demand. Effective groundwater management relies on accurate numerical models for flow and contaminant transport. Traditional calibration techniques often struggle with the uncertainty and spatial variability inherent in hydrogeological data. Although geostatistical simulations can represent this variability, their computational complexity limits their use in large-scale models. To overcome these challenges, ensemble methods like the Ensemble Kalman Filter (EnKF) and Ensemble Smoother (ES) have been introduced for model updates using spatiotemporal data. However, they face limitations in high-dimensional systems with sparse observational data, common in hydrogeology. This paper introduces an innovative data assimilation method combining Well-by-Well (WbW) and observation Type-by-observation Type (TbT) techniques. This approach utilizes local analysis to effectively calibrate large, complex groundwater models with limited observations, resulting in a more stable and accurate calibration process. The method is tested on a synthetic 3D model and a real regional groundwater flow model, showing significant improvements in calibration and predictions. A 3D synthetic model of a coastal aquifer with saltwater intrusion was developed to evaluate the WbW & TbT updates within the Ensemble Smoother with Multiple Data Assimilation (ES-MDA 4x) method. The results indicate improved calibration and reduced errors in hydraulic head and salt concentration predictions. This study demonstrates the robustness of the WbW & TbT method in calibrating the Ville Mercier regional hydrogeological model, showcasing its potential for complex hydrogeological settings. By updating parameters locally around each observation well, the WbW & TbT method addresses high-dimensional challenges while preserving data amplitude and managing the complexity of regional hydrogeological systems. Results confirm that this method enhances the accuracy and reliability of groundwater flow models, making it a vital tool for resource management amid environmental challenges. [ABSTRACT FROM AUTHOR]

Groundwater sustains human well-being and ecosystems functioning. Many regions in Europe have experienced declining groundwater levels caused by decreasing groundwater recharge (GWR) or increasing groundwater abstractions (GWAs). These changes can lead to groundwater-related stress, threatening ecosystems and water supplies. Existing groundwater stress indicators estimate stress during a given period but do not address how stress changes or show the uncertainty of future stress. We propose a novel indicator of future groundwater stress (GWSI) due to changes in GWR and GWA and, thus, the alteration of long-term mean annual groundwater discharge (GWD). Groundwater stress is defined as any alteration in GWD since ecosystems are adapted to an equilibrium state. Focusing on decreasing GWD, which is generally more harmful than increasing GWD, we quantified the future GWSI in Europe by integrating scenarios of GWR and GWA in 2070–2099. GWR was evaluated using an ISIMIP2b multi-model ensemble of eight global hydrological models driven by the output of four global climate models under two greenhouse gas emission scenarios. GWA scenarios for irrigation, domestic and manufacturing sectors were combined with the GWR projections to generate an ensemble of GWSIs, simplified into three groundwater stress scenarios (high, intermediate, low). Projected GWSIs vary significantly among the scenarios. For the high-stress scenario, 58% of Europe's land area is projected to experience a GWD decrease of at least 25% under RCP8.5 compared to 38% under RCP2.6, while the respective values are 26 and 1% for the intermediate-stress scenario. Groundwater demand management alone might not prevent GWD declines under the high-stress and intermediate scenarios, particularly under RCP8.5. Therefore, climate change mitigation might imperative for reducing the decline of GWD, especially in Eastern and Southeastern Europe, where changes in GWR are projected to be the primary cause of declining GWD (in the high abstraction scenario under RCP8.5). Under RCP2.6, reductions in GWAs by 25–75% might balance a GWD decline in parts of Spain and Italy where GWAs are high, even in the high-stress scenario. In line with the precautionary principle, we recommend adapting to the high-stress scenario to minimize harm to the beneficiaries of groundwater. [ABSTRACT FROM AUTHOR]

Small island communities often rely on groundwater as their primary source of fresh water. However, the limited land area and high proportion of coastal zones pose unique challenges to groundwater management. A detailed understanding of the subsurface structure can provide valuable insights into aquifer structure, groundwater vulnerability, saltwater intrusion, and the location of water resources. These insights can guide groundwater management strategies, for example, pollution regulation, promotion of sustainable agriculture, establishment of coastal buffer zones, and re‐naturalization of land cover. Ordinarily, structural characterization relies on geological mapping and boreholes, however, such approaches can have insufficient spatial resolution to aid groundwater management. In this study, transient electromagnetic (TEM) methods are used to map the subsurface of a small, 13.2 km2, Danish Island. The approach successfully identified two previously unknown paleochannels, where the interface between Quaternary aquifer units and an underlying Paleogene Clay aquiclude had maximum depths of 100 and 160 m below sea level. Before this, the interface was assumed to be 15 to 25 m below sea level: therefore, these paleochannels present substantial potential groundwater resources. Resolving geological heterogeneity within the Quaternary deposits was less successful and future work will focus on addressing these limitations. Nonetheless, in several locations, evidence of saltwater intrusion was observed within the Quaternary units. This work demonstrates how TEM mapping can identify water resources, define aquifer boundaries, and aid water management decisions. Such approaches could be applied in other areas, particularly small islands, where similar groundwater challenges exist. [ABSTRACT FROM AUTHOR]

This paper demonstrates an automated workflow for extracting network data from policy documents. We use natural language processing tools, part‐of‐speech tagging, and syntactic dependency parsing, to represent relationships between real‐world entities based on how they are described in text. Using a corpus of regional groundwater management plans, we demonstrate unique graph motifs created through parsing syntactic relationships and how document‐level syntax can be aggregated to develop large‐scale graphs. This approach complements and extends existing methods in public management and governance research by (1) expanding the feasible geographic and temporal scope of data collection and (2) allowing for customized representations of governance systems to fit different research applications, particularly by creating graphs with many different node and edge types. We conclude by reflecting on the challenges, limitations, and future directions of automated, text‐based methods for governance research. [ABSTRACT FROM AUTHOR]

Analytical and semi‐analytical models for stream depletion with transient stream stage drawdown induced by groundwater pumping are developed to address a deficiency in existing models, namely, the use of a fixed stream stage condition at the stream–aquifer interface. Field data are presented to demonstrate that stream stage drawdown does indeed occur in response to groundwater pumping near aquifer‐connected streams. A model that predicts stream depletion with transient stream drawdown is developed based on stream channel mass conservation and finite stream channel storage. The resulting models are shown to reduce to existing fixed‐stage models in the limit as stream channel storage becomes infinitely large, and to the confined aquifer flow with a no‐flow boundary at the streambed in the limit as stream storage becomes vanishingly small. The model is applied to field measurements of aquifer and stream drawdown, giving estimates of aquifer hydraulic parameters, streambed conductance, and a measure of stream channel storage. The results of the modeling and data analysis presented herein have implications for sustainable groundwater management. [ABSTRACT FROM AUTHOR]

In the investigation of optimal groundwater extraction in coastal regions, conventional assumptions typically revolve around unconfined aquifers with specified boundary conditions. In such cases, intricate solutions for groundwater management have been documented. However, within extensive delta plains, the extraction wells are frequently drilled in confined aquifers with not much variable-density flow. This circumstance, characterized by paleo-saltwater intrusion, is further complicated by the placement of wells at a considerable distance from the coastal line. As a result, the design and implementation of groundwater supply systems in these areas necessitate strategic groundwater management to optimize groundwater utilization while mitigating the potential risk of saltwater intrusion. Analytical solutions and an optimization problem approach have been applied to address this challenge and solve the differential equations governing confined aquifers with salt–freshwater interfaces. These methodologies provide simplified yet dependable conditions tailored to the study area. A case study conducted in Vinh Hung district, Long An province, is focused on determining the optimal pumping rate for production wells to forestall saltwater intrusion during groundwater extraction. Here, the focus is on the migration of older saltwater towards inland pumped wells, rather than the influence of recent seawater encroachment. The findings contribute valuable insights into achieving an equilibrium between maximizing groundwater utilization and preventing saltwater intrusion in the aquifer systems by a simplified approach. [ABSTRACT FROM AUTHOR]

The Qinglian River plays a significant role in China's national water conservation security patterns. To clarify the relationship between hydrogeochemical properties and groundwater quality in this karst-fissure aquifer system, drilling data, hydrochemical parameters, and δ2H and δ18O values of groundwater were analyzed. Multiple indications (Piper diagram, Gibbs diagram, Na+-normalized molar ratio diagram, chloro-alkaline index 1, mineral saturation index, and principal component analysis) were used to identify the primary sources of chemicals in the groundwater. Silicate weathering, oxidation of pyrite and chlorite, cation exchange reactions, and precipitation are the primary sources of dissolved chemicals in the igneous-fissure water. The most relevant parameters in the karst water are possibly from anthropogenic activities, and other chemicals are mostly derived from the dissolution of calcite and dolomite and cation exchange reactions. Notably, the chemical composition of the deep karst water from the karst basin is mainly influenced by the weathering of carbonate and cation exchange reactions and is less affected by human activities. The hydrogeochemical properties of groundwater in the karst hyporheic zone are influenced by the dissolution of carbonates and silicates, evaporation, and the promotion effect of dissolution of anorthite or Ca-containing minerals. Moreover, the smallest slope of the groundwater line from the karst hyporheic zone among all groundwater groups revealed that the mixing effects of evaporation, isotope exchange in water–rock interaction or deep groundwater recharge in the karst hyporheic zone are the strongest. The methods used in this study contribute to an improved understanding of the hydrogeochemical processes that occur in karst-fissure water systems and can be useful in zoning management and decision-making for groundwater resources. [ABSTRACT FROM AUTHOR]

In arid and semi-arid regions, groundwater is often the only available water source. However, overexploitation and pollution have led to a decrease in groundwater quantity and quality. Therefore, the proper management of groundwater resources is essential to promote sustainable development. Numerical simulation models (NSMs) have emerged as a valuable tool to address these challenges due to their ability to accurately and efficiently model groundwater systems. This study provides a comprehensive systematic review to evaluate the current knowledge on using numerical groundwater flow models for planning and water resource management in countries in the American region. A total of 166 research articles were published between the years 2000 and 2024. We analyzed and summarized details such as the study regions, numerical simulation methods and applied software, performance metrics, modeling units, modeling limitations, and prediction scenarios. In addition, we discuss alternatives to address the constraints and difficulties and suggest recommendations for future research. The continued research, improvement, and development of numerical groundwater models are essential to ensure the sustainability of groundwater resources. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Over the last decades, as a consequence of wastewater discharges and other anthropogenic sources, severe nitrate (NO3−) pollution has developed in municipal environment causing global concern. Thus, eliminating the potential sources of pollution is one of the major challenges of the twenty-first century, whereby sanitation services are essential for ensuring public health and environmental protection. In the present study, long-term monitoring (2011–2022) of shallow groundwater NO3− contamination in municipal environment was carried following the construction of the sewerage network (2014) in the light of the pre-sewerage situation. Our primary aim was to assess the long-term effects of sewerage on nitrate NO3− levels in the shallow groundwater and evaluate the efficiency of these sanitation measures over time. Based on the results, significant pollution of the shallow groundwater in the municipality was identified. During the pre-sewer period, NO3− concentrations exceeded the 50 mg/L limit in the majority of monitoring wells significantly, upper quartile values ranged between 341 and 623 mg/L respectively. Using Nitrate Pollution Index (NPI) and interpolated NO3− pollution maps, marked spatial north–south differences were detected. In order to verify the presence of wastewater discharges in the monitoring wells, the isotopic ratio shifts (δ) for 18O and D(2H) were determined, confirming municipal wastewater effluent. Variations in NO3−/Cl− molar ratios suggest also contamination from anthropogenic sources, including septic tank effluent from households and the extensive use of manure. Data series of 7 years (2015–2022) after the investment indicate marked positive changes by the appearance of decreasing trends in NO3− values confirmed by Wilcoxon signed rank test and ANOVA. By comparing the pre- and post-sewerage conditions, the mean NO3− value decreased from 289.7 to 175.6 mg/L, with an increasing number of monitoring wells with concentrations below the limit. Our results emphasise the critical role of sanitation investments, while also indicating that the decontamination processes occur at a notably slow pace. Detailed, long-term monitoring is therefore essential to ensure accurate follow-up of the ongoing changes. The results can provide information for local citizens and authorities to improve groundwater management tools in the region. [ABSTRACT FROM AUTHOR]

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

In California, Groundwater Sustainability Agencies (GSAs) are basin/catchment-specific water organizations mandated by the Sustainable Groundwater Management Act of 2014 to manage groundwater sustainably by 2040/2042. A GSA can charge replenishment fees for pumped groundwater and these fees can be used to: (a) monitor basin hydrologic conditions; (b) improve the water budget accuracy; (c) increase water availability through management actions and projects; (d) mitigate undesirable results; and/or (e) pay for activities including issuing allocations and limiting production to allocations. In England, housing is frequently proposed in river basin catchments that face water resource challenges. High profile examples are the Arun Valley and Cambridge. The current National Planning Policy Framework manages water resource planning strategically through water company Water Resource Management Plans or Environment Agency River Basin Management Plans. These processes can be slow to respond to development requirements. England might look to California's practices that require water users and developers to pay for 'water credits' or fees. This could involve a 'Watermaster' charged with local or catchment scale resource management and project implementation. This Watermaster could engage all stakeholders including the local water company, farmers, the Environment Agency and the local authority, none of whom is well positioned to act in isolation. [ABSTRACT FROM AUTHOR]

Many major cities worldwide have inevitably experienced excessive groundwater pumping due to growing demands for freshwater in urban development. To mitigate land subsidence problems during urbanization, various regulations have been adopted to control groundwater usage. This study examines the transition in the post‐subsidence stage, especially in metropolitan areas, to adaptively adjust subsidence prevention strategies for effective groundwater management. Taking the Taipei Basin as an example, historical data reveals significant subsidence of more than 2 m during early urban development, with subsidence hazards largely mitigated over decades. However, the rising groundwater level poses a risk to the stability of engineering excavations. In this study, 29 X‐band Cosmo‐Skymed constellation (CSK) images were utilized with the Persistent Scatterer InSAR (PSInSAR/PSI) technique to monitor surface displacements during the construction of the Mass Rapid Transit system. Correlating groundwater levels helps identify the heterogeneous hydrogeological environment, and the potential groundwater capacity is assessed. PSI time‐series reveal that approximately 2 cm of recoverable land displacements correspond to groundwater fluctuations in the confined aquifer, indicative of the typically elastic behavior of the resilient aquifer system. The estimated groundwater storage variation is about 1.6 million cubic meters, suggesting this potential groundwater capacity could provide available water resources with proper management. Additionally, engineering excavation safety can be ensured with lowered groundwater levels. This study emphasizes the need to balance groundwater resource use with urban development by adjusting subsidence prevention and control strategies to achieve sustainable water management in the post‐subsidence stage. Plain Language Summary: Groundwater is used as an important freshwater resource in global urban development, but over‐exploitation often leads to subsidence problems. Once land subsidence situation is under controlled, attention turns to how to balance urban development with environmental protection. This study takes a metropolitan area in a post‐subsidence period as an example and uses satellite technique to estimate potential groundwater volumes. It suggests that with proper management, groundwater resources can be fully utilized and related engineering disasters can be prevented. Key Points: Integrating InSAR and numerical model for transient‐like state groundwater level mappingQuantifying changes in potential groundwater storage as available freshwater resourcesEfficient groundwater utilization for achieving sustainability in post‐subsidence stages [ABSTRACT FROM AUTHOR]

Groundwater resources frequently trend toward unsustainable levels because, absent effective institutions, individual water users generally act independently without considering the impacts on other users. Hydro‐economic models (HEMs) of human‐natural systems can play a positive role toward successful groundwater management by yielding valuable knowledge and insight. The current study explores how an HEM that captures essential physical and economic characteristics of a system can shed light on the system's processes and dynamics to benefit stakeholders, managers, and also researchers. These propositions are illustrated using the Harney Basin, Oregon, which has seen large groundwater declines in the past 20 years. The HEM shows that: (a) although current groundwater pumping rates will gradually raise costs and reduce well yields, irrigators gain the highest aggregate economic return by continuing current pumping; (b) lowland areas of the basin are hydrologically connected, which limits the efficacy of remedies focused on regulations only in some portions of the basin; (c) community expectations regarding the efficacy of several proposed solutions are overly optimistic; and (d) the study's scenarios identify interventions that would stabilize the groundwater system and prevent additional adverse impacts on residential and livestock wells and groundwater‐dependent ecosystems. These interventions would require limiting groundwater pumping by nearly half and reducing annual profits by $7.5–$9.0M. The HEM also demonstrated its value to researchers: its insights shifted attention toward questions about Oregon's existing groundwater institutions and their inability to adaptively manage the transition from abundant groundwater to scarce groundwater in a timely manner. Plain Language Summary: This study develops a hydro‐economic model (HEM) linking an economic model of irrigated agricultural production with a three‐dimensional groundwater hydrology model of the Harney Basin, Oregon, to better understand the causes and possible solutions to the large groundwater declines in the past 20 years. Those declines have had adverse impacts on the farmers who irrigate with groundwater, but also on residential wells and environmental flows supplying groundwater‐dependent ecosystems. The HEM simulates 30‐year future scenarios for a baseline and alternative scenarios representing interventions aimed at stabilizing the groundwater system. Results reveal that although current groundwater pumping rates will gradually raise costs and reduce well yields, irrigators gain the highest aggregate economic return by continuing current pumping rates. The analysis shows that sustainable pumping rates were surpassed 20 years before declining groundwater levels were generally recognized. Results show that because the basin is hydrologically connected, the efficacy of regulations focused only in some portions of the basin are limited; and community expectations regarding benefits from several proposed solutions are found to be overly optimistic. A number of interventions are identified that would stabilize the groundwater system; however, these interventions would require lowering pumping by nearly half and reducing annual profits by $7.5–$9.0M. Key Points: A hydro‐economic groundwater model (HEM) of the Harney Basin shows that HEMs can improve understanding and advance successful managementModeled scenarios reveal, for example, that proposed technology or spatially‐targeted solutions do little to stabilize groundwater levelsHEM studies can alter the way researchers understand a system, bringing focus toward key factors or even changing the key research question [ABSTRACT FROM AUTHOR]

Large, confined aquifer systems play a vital role in sustaining human settlements and industries in many regions. Understanding the sustainability of these water resources requires the evaluation of groundwater storage change. Direct in‐situ observation of groundwater storage is limited by the distribution and availability of groundwater level and aquifer storativity data. Here, we use and compare two auxiliary methods, applied at basin and sub‐basin scales, to assess groundwater storage changes in the Great Artesian Basin (GAB), one of the World's largest confined aquifer systems. The first, the groundwater budget, derives storage change as the residual of fluxes in and out of the GAB, assuming they are all accounted for and accurately estimated. The second uses time‐variable gravity data from GRACE satellites to estimate temporal changes in groundwater mass, assuming that all other components of the terrestrial water mass change detected by GRACE are correctly subtracted. Despite the depletion observed during the 20th century, groundwater storage is mostly stable during 2002–2022. An increase in storage is detected in the Surat sub‐basin, a major recharge area. This increase is attributed to an over‐representation of large recharge events during the study period and/or storage recovery following rehabilitation of free‐flowing bores. The approach consisting in disaggregating GRACE data assumes that water storage changes in confined aquifers is dominated by changes in the GAB, and as such, it may overestimate the increase in the GAB by incorrectly attributing the increase occurring in overlying aquifers to the GAB. In contrast, the recharge estimates used in the groundwater budgets do not account for flood recharge and might underestimate storage increase in the GAB. Plain Language Summary: Monitoring groundwater storage in large, confined aquifers is often impossible as it requires large groundwater level and lithological data sets that are often unavailable. However, monitoring is crucial for assessing and managing the sustainability of this resource and manage it appropriately. This study uses and compares two auxiliary methods, applied at basin and sub‐basin scales, to assess groundwater storage changes in the Great Artesian Basin (GAB), one of the World's largest confined aquifer systems. The groundwater budget approach estimates water storage changes by adding up the amounts of groundwater that goes in and out of the aquifer system. The satellite gravimetry approach uses the temporal changes of Earth's gravity field to infer changes in groundwater mass. Both methods agree that, despite the depletion observed during the 20th century, groundwater storage in the GAB was mostly stable during 2002–2022. An increase in groundwater storage is detected near major recharge areas. It is attributed to an over‐representation of large recharge events during the study period and/or groundwater storage recovery following capping of free‐flowing bores. Key Points: GRACE and groundwater budgets agree that water storage in the Great Artesian Basin was stable for the period 2002–2022Increased storage in the Surat sub‐basin is attributed to bore rehabilitation and/or increased recharge during the study periodWithin the Surat sub‐basin, increased storage may be overestimated by GRACE and/or underestimated by the groundwater budgets [ABSTRACT FROM AUTHOR]

The management of transboundary aquifers across the Americas faces significant challenges, especially as climate change and population growth intensify groundwater stress. Groundwater use has increased to support domestic, industrial, and agricultural demands but has been extracted through unregulated withdrawals, leading to the severe degradation of aquifer health and transboundary frictions. This study focuses on how hydro-diplomacy can accelerate the adaptive governance of shared groundwater resources in three key regions: Canada–USA, USA–Mexico, and Mexico–Guatemala–Belize. We utilized a mixed methodology by integrating a transect approach, borrowed from ecology, into the field of geopolitics. To compare the hydro-diplomatic relations and groundwater governance across a continental gradient in the Americas, we conducted a literature review and employed the TWINS conflict–cooperation matrix to evaluate governance frameworks and hydro-diplomatic interactions across time. Our findings demonstrate that hydro-diplomacy plays a pivotal role in expediting agreements, fostering transboundary data sharing, and supporting participatory governance models. In particular, the presence of supranational bodies such as the International Joint Commission (IJC) between Canada and the USA has been effective in maintaining long-term collaboration through social learning and technical cooperation. Meanwhile, in regions like Mexico–Guatemala–Belize, the absence of robust institutions has hindered progress, with limited financial and knowledge-sharing networks. This study highlights the need for improved cross-border cooperation mechanisms and the establishment of common monitoring protocols to better manage aquifer resources under the pressures of climate change. The results support the development of more adaptive transboundary groundwater management strategies aligned with Sustainable Development Goal (SDG) 6.5.2 and call for broader geopolitical cooperation to address the complexities of groundwater governance. [ABSTRACT FROM AUTHOR]

The document discusses the impact of climate change, human activities, and socio-economic factors on irrigation water management and agricultural water productivity. It emphasizes the importance of improving agricultural water productivity to ensure global water and food security. The document presents research on various topics, including the adoption of water-saving technologies like Alternate Wetting and Drying (AWD), the role of zeolite in rice cultivation, plastic film mulching, groundwater well placement optimization, and the effects of agricultural return flow on downstream rivers. Additionally, it explores the impact of mining on water resources, factors influencing declining runoff, vegetation response to drought, and the decomposition of crop straw for sustainable agricultural development. [Extracted from the article]

Effective groundwater management is crucial under the current climatic conditions, addressing both qualitative and quantitative aspects. An important step in delineating groundwater potential zones involves remote sensing (RS) data and geographic information systems (GISs), facilitating resource assessment, and the implementation of suitable field data management. This study introduces the delineation of potential groundwater zones using seven layers and the Multi-Criteria Decision Analysis (MCDA) method. Satty's Analytic Hierarchy Process (AHP) was employed to rank the seven selected parameters, contributing to the advancement of groundwater research and resource assessment. All seven thematic layers (Rainfall, Geology, Land Use/Land Cover, Drainage Density, Elevation, Slope, and Soil) were prepared and analyzed to delineate groundwater potential zones. The resulting groundwater potential zone map was categorized into four classes, Very Good, Good, Moderate, and Poor, covering areas of 81.53 km2 (45.1%), 56.36 km2 (31.2%), 19.54 km2 (10.8%), and 23.17 km2 (12.8%) of the total area, respectively. The accuracy of the output was validated by comparing it with information on groundwater prospects in the area, and the overall accuracy of the method was approximately 72%. High-yield boreholes were drilled and concentrated in the Very Good groundwater potential zones, while low-yield ones were developed in the Poor areas. [ABSTRACT FROM AUTHOR]

Introduction: Moral Intelligence (MI) as a concept has gained importance Increasing water scarcity as a result of climate change and its coincidence with population growth, economic development, and the resulting rising demand has become an important challenge in most parts of the world. In numerous nations, such as Iran, frequent occurrences of droughts, combined with the extensive utilization of surface and groundwater resources, have resulted in numerous environmental detriments, including a decrease in groundwater levels, land subsidence, deterioration of water quality, and, more recently, the emergence of dust storms due to soil erosion and desertification. In this situation, stakeholders can play an efficient role in water management and the alleviation of water scarcity and its negative environmental externalities in the context of good water governance. Method: This investigation endeavored to examine the functions and importance of individuals or groups with a vested interest in groundwater resources within the Hamedan-Bahar Plain. Additionally, it aimed to evaluate their influence and motivations through the utilization of the power-interest matrix (PIM) and important-performance matrix techniques. A total of 86 people were identified who could and were allowed to be interviewed through the snowball method. Then a 10-point scale questionnaire was used to rate the questions. To examine the power and interest of the stakeholders, the IPM test was carried out using the smart pls.3 software, and the results were classified based on the average values and the overall impact. The results reveal that 20 institutions and agencies have an effective role in the governance of groundwater resources in the Hamedan- Bahar plain. Furthermore, the analysis of the PIM revealed that the most powerful organizations that play the most important role in the management of the groundwater resources of the studied area are the regional water organization, the representatives of the parliament, and the governor, respectively. Results and discussion: Based on the research findings, the governance "power" index of organizations and institutions with power (39.77%) and total impact (0.516) is higher and more effective than the value of benefits with power (36.13%) and total impact (0.48). Accordingly, paying attention to the role and influence of the power of stakeholders will be an important and effective point in the plans and strategies for groundwater resources in the Hamadan-Bahar plain. In the end, strategies are suggested to each stakeholder for better implementation of the programs and strategies. [ABSTRACT FROM AUTHOR]

Studying groundwater renewal time is a valuable tool to deepen the comprehension of sustainable groundwater resources specific to arid regions. Tritium is a radioactive isotope of hydrogen often used as an environmental tracer to study groundwater renewal time. The present work reports groundwater renewal times by the environmental tracer tritium to understand sustainable water resources in arid regions. First, groundwater samples were collected from wells in northeastern arid regions of Saudi Arabia. Then, an electrolysis process was employed to significantly increase the tritium level from twenty-five to thirty times the original concentration. Subsequently, the enriched water was analyzed using a liquid scintillation counter under optimized measurement conditions to determine the tritium concentration precisely. Two internationally recognized tritium laboratories conducted independent assessments to validate the estimated tritium levels. The verified tritium concentration was then used to estimate the groundwater renewal time using the Morgenstern and Pimenta curves. The results suggest that most of the monitored wells in the surveyed areas are more than a century old. Conversely, a few monitoring wells exhibit renewal times of several hundred years and may be considered nonrenewable water sources. These studies help to understand the geochemical characteristics of arid regions to ensure the sustainable management and protection of groundwater resources. [ABSTRACT FROM AUTHOR]

Groundwater quality is a critical concern for human health, particularly in urban areas like the eastern part of Tehran Plain, where geological features and anthropogenic activities contribute to contamination risks. This study aimed to assess the quality of groundwater in this region, focusing on its implications for public health. The objectives of the study were to identify factors influencing hydrogeochemistry, evaluate environmental risk based on metal(loid)s using water quality indices, and conduct a health risk assessment. Groundwater samples were collected and analyzed for chemistry, water quality, heavy metal contamination, and associated health risks. The results indicated a relatively stable pH condition and a wide variation in the concentration of dissolved solids. The Water Quality Index (WQI) was employed to evaluate the overall water quality, revealing that approximately 50% of the samples fell into the poor and very poor quality categories, with two samples deemed unsuitable for drinking. Heavy metal contamination varied across different metals, with some indicating low levels while others showed moderate to very high levels. Priority pollutants such as mercury and arsenic were identified as having a greater potential impact on water quality deterioration. Exposure and health risk assessments indicated a negligible risk associated with aluminum exposure but high risks associated with arsenic, chromium, and mercury exposure. Carcinogenic risk assessments for arsenic, chromium, and mercury exceeded acceptable thresholds, emphasizing the urgent need for further investigation into contamination sources and strategies for mitigation. These findings highlight the importance of continuous monitoring and sustainable groundwater management practices, providing valuable insights for other regions facing similar challenges in groundwater quality and public health. [ABSTRACT FROM AUTHOR]

The scarcity of freshwater resources in coastal plains has raised global concerns. Understanding the chemical characteristics and evolution of groundwater in coastal plains is crucial for ensuring sustainable water supply for residents and irrigation. This study focuses on a representative profile of the Luanhe plain, systematically analyzing hydrochemistry and stable isotopes of seawater, river water, and groundwater samples to elucidate groundwater chemistry evolution and investigate the influence of evaporation and mixing processes. Results showed that shallow groundwater was predominantly of the Ca-HCO3 type, formed through the dissolution of halite, carbonate, and silicate minerals in the aquifer. Under the influence of evaporation and mixing processes, there was a transition in the chemical type towards Ca-Na-HCO3 type. Especially in areas influenced by seawater intrusion at estuaries, a rapid shift towards Na-Cl type occurred. In addition, deep aquifers evolved predominantly into Ca-HCO3 type groundwater through the leaching of silicate and carbonate minerals within the aquifer matrix. Along the flow path, influenced by cation exchange and mixing processes, the water chemistry underwent a shift from the Ca-HCO3 type to the Na-HCO3 type. The river water chemistry was primarily influenced by evaporation and the erosion of silicate and sulfate minerals from the riverbed. At estuarine zones, intense seawater intrusion significantly increased salinity and shifted the water chemistry from a Ca-Cl type to a Na-Cl type. This study elucidated the evolution mechanisms and influencing factors of coastal groundwater chemistry, providing scientific insights for local groundwater resource management. [ABSTRACT FROM AUTHOR]

Groundwater depletion in Bangladesh's Barind tract poses significant challenges for sustainable water management. This study aims to delineate groundwater recharge potential zones in this region using an integrated geospatial and Analytical Hierarchy Process (AHP) approach. The methodology combines remote-sensing data with GIS analysis, considering seven factors influencing groundwater recharge: rainfall, soil type, geology, slope, lineament density, land use/land cover, and drainage density. The AHP method was employed to assess the variability of groundwater recharge potential within the 7586 km2 study area. Thematic maps of relevant factors were processed using ArcGIS software. Results indicate that 9.23% (700.22 km2), 47.68% (3617.13 km2), 37.12% (2816.13 km2), and 5.97% (452.70 km2) of the study area exhibit poor, moderate, good, and very good recharge potential, respectively. The annual recharge volume is estimated at 2554 × 106 m3/year, constituting 22.7% of the total precipitation volume (11,227 × 106 m3/year). Analysis of individual factors revealed that geology has the highest influence (33.57%) on recharge potential, followed by land use/land cover (17.74%), soil type (17.25%), and rainfall (12.25%). The consistency ratio of the pairwise comparison matrix was 0.0904, indicating acceptable reliability of the AHP results. The spatial distribution of recharge zones shows a concentration of poor recharge potential in areas with low rainfall (1200–1400 mm/year) and high slope (6–40%). Conversely, very good recharge potential is associated with high rainfall zones (1800–2200 mm/year) and areas with favorable geology (sedimentary deposits). This study provides a quantitative framework for assessing groundwater recharge potential in the Barind tract. The resulting maps and data offer valuable insights for policymakers and water resource managers to develop targeted groundwater management strategies. These findings have significant implications for sustainable water resource management in the region, particularly in addressing challenges related to agricultural water demand and climate change adaptation. [ABSTRACT FROM AUTHOR]

Groundwater recharge zone identification is vital for managing water resources, particularly in semi-arid and dry climates. Accurate and quantifiable assessment is necessary for the sustainable management of groundwater resources, and it is possible to carry this method out using modern techniques and technical standards. To identify likely groundwater locations in the Diyala River Catchment, Iraq, which serves as an example study basin, the current research examines a new methodology that employs a geographic information system, and an Analytical Hierarchy Process connected with remote sensing data. The technique of ArcGIS was employed to generate spatially distributed thematic layers of rainfall, lithology, slope, drainage density, land use/land cover, relief and soil. The raster data from these layers were then converted and categorized. The weights assigned to thematic strata depended on their significance relative to groundwater occurrence. A pairwise judgement matrix for the Analytical Hierarchy Process was used, with the categorized ranking, to assess the standardized weights of the layers under consideration. The layers for the formation of groundwater zones have then been placed using the overlay-weighted summation approach. Three regions, which are classed as excellent, good and moderate, have been identified on the resulting groundwater potential zones map, representing roughly 29, 69 and 2% of the basin's total area, respectively. The study's conclusions indicate that, in such a climate, the adopted strategy would produce favourable results to promote the organizing of opinions and the sustainable use of groundwater resources. [ABSTRACT FROM AUTHOR]

The Sangu Spring Basin is located in an important economic area, and groundwater is the main source of water for local life and industry. Understanding the sources of chemical components in groundwater is important for the development and utilization of groundwater. In this paper, we analyzed the origin of the chemical components of groundwater and their evolution in the Sangu Spring Basin using statistical analysis, Piper diagrams, Gibbs diagrams, ion ratios, and combined hydrochemistry–isotope analyses. The results show that the groundwater in the Sangu Spring Basin is mainly derived from atmospheric precipitation, that the groundwater in stagnant and confined environment zones was formed under colder climatic conditions, and that the surface water (SW) has a close hydraulic relation with the groundwater. Water–rock interaction is the main factor controlling the composition of groundwater. The compositions of groundwater are mainly derived from carbonate weathering, silicate weathering, and dissolution of gypsum. Na+ and K+ in groundwater mainly come from the dissolution of albite and potassium feldspar, rather than rock salt. Ion exchange occurs in karst groundwater (KGW) and fissure groundwater (FGW), and ion exchange is dominated by the exchange of Mg2+ and Ca2+ in the groundwater with Na+ and K+ in the rock or soil. Sulfate in groundwater is derived from dissolution of gypsum, infiltration of atmospheric precipitation, and leakage of SW. Groundwaters with the highest sulfate content are located in the vicinity of SW, as a result of receiving recharge from SW seepage. Groundwaters with higher sulfate contents are located in the stagnant and deeply buried zones, where sulfate is mainly derived from the dissolution of gypsum. SW seepage recharges groundwater, resulting in increased levels of Cl−, NO3− and SO42− in groundwater. These insights can provide assistance in the protection and effective management of groundwater. [ABSTRACT FROM AUTHOR]

The Main Karoo Basin in South Africa is a typical example of an expanding arid region dependent on groundwater resources. Dolerite dikes in the region, analogous to dolerite dikes worldwide, are known to influence subsurface groundwater flow and spatially relate to high-yielding boreholes. Here, the effect of dolerite dikes on groundwater flow is remotely assessed using the Modified Soil Adjusted Vegetation Index derived from high-resolution multi-spectral satellite imagery. From imagery collected during the wet and dry seasons of 2018 and 2021, two aquifer models relating to 505 dikes were identified; (1) barrier-controlled aquifers are induced by ~ 56% of dikes, (2) fractured aquifers are induced by ~ 35% of dikes. Surficial areas overlying aquifers are also shown to sustain vegetation growth through dry seasons. This research demonstrates the efficacy of vegetation indices to rapidly characterise dike-related aquifer models and their seasonal sustainability, critical for effective groundwater exploration and management. [ABSTRACT FROM AUTHOR]

Groundwater resource management and development should be done sustainably, which calls for accurate assessment based on new methods and scientific principles. There is an increasing demand for potable water supplies, to meet the woefully inadequate domestic water needs in the Batcham municipality (west of Cameroun). The dearth of knowledge on sustainable management of water resources is to blame for this predicament. As integrated methodologies are not used in groundwater exploration programs, the current problem has gotten worse. Innovative scientific principles of groundwater resource exploration are required to effectively counteract the non-rationalization of water and the problem of unacceptable failure rates in drilled water borehole development. This will improve the appropriate and sustainable use of these resources. Therefore, the goal of this research is to map groundwater potential zones by utilizing readily available datasets and remote sensing (RS), GIS, Frequency Ratios (FR), and multi-criteria analysis (AHP) techniques. The database used is made up of geological data, hydroclimatic data, well data, and satellite images. Each of the methods used is based on the study of the relationships between the factors controlling the groundwater potential. Among these factors, ten (10) were retained based on previous work; these are slope, elevation, land use, land cover, lineament density, drainage density, topographic wetness index, curvature, geology, rainfall, and the static water level. The AHP allowed, according to the user's expertise, to assign weights to each factor controlling the water potential. The FR made it possible to study the relationships linking each variable with high flow rates. The thematic layers obtained were integrated into a GIS environment to generate the groundwater potential map. Four classes of groundwater potential have been identified: bad, moderate, good, and excellent. The bad classes represent 8.32% and 11.21%; moderate 36.57% and 28.70%; good 43.55% and 38.93%; and excellent 11.56% and 21.16%, for the AHP and FR models, respectively. The overlying of wells with high flow rates on areas of excellent groundwater potential shows perfect concordance, which validated the final map. Likewise, the resulting map was validated by sensitivity curve analysis, and the receiver operating characteristic (ROC) curve from which result accuracy was obtained is 70.63% and 80.28% for the AHP method and FR method, respectively. Finally, the FR model outperformed the AHP model in terms of performance and it is possible to use these dependable models to describe groundwater potential zones in the other regions of Cameroon. [ABSTRACT FROM AUTHOR]

Concentrations of 222Rn and other toxic metals (Ni, Cu, Fe, Cd, Zn, Pb, Cr, and Mn) were measured by alpha spectrometry using Rad7 and atomic absorption spectrophotometry, respectively, in the water samples from the Ilokun dumpsite, Ado-Ekiti, Nigeria. The physicochemical parameters of the groundwater were also assayed to determine its suitability for drinking and irrigation purposes. While the physicochemical parameters met the World Health Organization (WHO)-safety standards, Cu, Fe, Cd, Pb, Cr, and Mn exceeded permissible limits. Hazard index (HI) values for adults (8.40) and children (39.23) indicated heightened susceptibility to non-carcinogenic health risks among both age group populations. The 222Rn concentrations present in the studied samples range from 5.4 to 23.1 Bq l−1 with an average of 13.9 Bq l−1. Approximately 60% of the samples have radon concentrations above the US Environmental Protection Agency (EPA)-maximum contaminant level of 11.1 Bq l−1. The evaluated radiation doses to the stomach and respiratory tract due to radon content in the water are well below the WHO-specified individual dose criterion of 0.1 mSv year−1. This study suggests a need for groundwater resource management strategies and measures to protect human health from radiological and toxicological risks associated with groundwater consumption around the Ilokun dumpsite. [ABSTRACT FROM AUTHOR]

Numerous and diverse groundwater habitats suitable for sustaining aquatic invertebrate communities exist across Australia. These habitats include enclosed subterranean aquifer systems, fractured rock, alluvial aquifers, perched aquifers, artesian springs, and spring-fed seeps and marshes. Crustaceans are a dominant member of these groundwater-associated invertebrate communities, and amphipods, both stygobiont and associated epigean species, are particularly diverse yet are still relatively poorly known. We review both the diversity and distributions of Australian amphipods associated with groundwater habitats, describing hotspots of diversity, providing notes on the unique Australian habitats, and examining the extraordinary species diversity and endemism of the Australian species. Our review highlights the significance of Australian groundwater ecosystems, their associated biodiversity, and the importance in considering these ecosystems in groundwater conservation management plans. [ABSTRACT FROM AUTHOR]

Driven by the need for integrated management of groundwater (GW) and surface water (SW), quantification of GW–SW interactions and associated contaminant transport has become increasingly important. This is due to their substantial impact on water quantity and quality. In this review, we provide an overview of the methods developed over the past several decades to investigate GW–SW interactions. These methods include geophysical, hydrometric, and tracer techniques, as well as various modeling approaches. Different methods reveal valuable information on GW–SW interactions at different scales with their respective advantages and limitations. Interpreting data from these techniques can be challenging due to factors like scale effects, heterogeneous hydrogeological conditions, sediment variability, and complex spatiotemporal connections between GW and SW. To facilitate the selection of appropriate methods for specific sites, we discuss the strengths, weaknesses, and challenges of each technique, and we offer perspectives on knowledge gaps in the current science. [ABSTRACT FROM AUTHOR]

The conjunctive use of surface water and groundwater is practiced worldwide as a measure to address water supply uncertainty. This paper focuses on a scenario in which an aquifer is open to multiple users and examines the impact of such an open-access environment on the stabilization function of conjunctive management. We construct a non-cooperative stochastic dynamic game model where multiple users utilize groundwater intake from a common aquifer as a complement to fluctuating surface water. We also propose a simpler baseline applicable to dynamic environments to compute the benefits of the stabilization function when users are unable to adjust groundwater intake to surface water uncertainties. We then apply the model to the real-world case of the water supply environment of the Cao'e River in China. Simulation results show that open access leads to diminishing stabilization values as higher pumping costs due to declining stocks lead to a weakening of users' incentive to utilize groundwater flexibly. Furthermore, the stabilization function itself is destabilized as the number of users increases. This is because greater groundwater intake and a decline in stocks amplify variations in pumping costs caused by different patterns of surface-water fluctuation. [ABSTRACT FROM AUTHOR]

Over-exploitation of groundwater in arid and semi-arid regions requires an understanding of dynamics for effective management strategies. This study uses an artificial neural network (ANN) to predict groundwater levels using initial water level, pumping, and hydrological and meteorological input variables. A sensitivity analysis assessed predictors' impact on accurate groundwater level prediction. The accuracy of predictions by the ANN model was examined through different performance evaluation criteria and the result achieved is satisfactory as compared to reasonable statistical indicator values. A comparison of results simulated by the ANN model and numerical groundwater flow model (MODFLOW) was carried out and it was found that the prediction of the ANN model was consistently superior to that of the numerical model. Therefore, data-driven models such as ANN can provide better predictions of groundwater level that will aid in groundwater resource management. [ABSTRACT FROM AUTHOR]

The analysis of the influence of human activities and climate change on groundwater is an important basis for formulating groundwater management policies. However, the relationship between climate change, human activities and groundwater system is complex, and the research on the response of groundwater to changing environment is in the initial stage. In this paper, the interactions between groundwater water cycle and climate change and human activities are analyzed, based on climate change data and hydrogeological information from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). The MODFLOW model was used to develop a numerical model of shallow groundwater movement in Zhongmu County, Henan province, and to predict the response of groundwater levels to climate change and human activities in three cases from 2016 to 2050. The results show that under the current scenario, the groundwater level will decrease at an average annual rate of 4.24 cm/A from 2016 to 2050. Under the climate change scenario, the precipitation increased by an average of 5.01%, the annual evaporation increased by an average of 17.84% and the annual temperature increased by an average of 1.29 °C from 2016 to 2050 under the three emission cases of RCP2.6, RCP4.5 and RCP8.5, under the climate change–autonomous human activities scenario, when water conservation and South–North Water Transfer Project water supply are implemented simultaneously, the water table will decrease by an average of 5.58 CMA per year under the direct impact scenario and by an average of 4.44 CMA per year under the indirect impact scenario, the water table dropped by 3.21 cm/A. The changing environment will have an important effect on groundwater circulation, and appropriate measures must be taken to deal with the continuous decline of groundwater level. [ABSTRACT FROM AUTHOR]

Groundwater is gradually becoming the primary water source for humans and other living organisms to sustain life on Earth. The groundwater quality in the industrial regions has been significantly contaminated in recent years due to anthropogenic activities, leading to various human health issues. In this study, the groundwater quality and hydrogeochemical characteristics of the Ranipet Industrial Corridor (RIC) were assessed by employing multivariate statistics, standard scatter plots, and the water quality index (WQI). Forty groundwater samples (12 bore wells and 28 open wells) were collected during the post-monsoon (January 2022) season, and the estimation of physicochemical parameters was carried out based on American Public Health Association (APHA) guidelines. The evaporation and rock-water interaction are controlling groundwater hydrochemistry in the study area, as illustrated by Gibbs's diagram. In contrast, 82% of groundwater samples are severely affected by human activity, and 12% are impacted by silicate weathering, illustrated by scatter plots. According to the Chadha diagram, gypsum dissolution is the primary reason for the chemical composition of groundwater in the RIC (87.5%). The primary hydrochemical processes in the study area include silicate weathering, evaporation, ion exchange, and rock-water interaction. The Mukundarayapuram, Navlock, and Melvisharam region's groundwater quality is unsuitable (92.5%) for irrigation due to the high concentration of sodium, based on Sodium Adsorption Ratio (SAR) results. Anthropogenic activities are the primary cause of groundwater degradation and hydrogeochemical changes, with the groundwater quality of RIC being over 60% very poor. A comprehensive treatment procedure before effluent discharge and stringent water regulating policies governed by environmental monitoring organizations are the pressing priorities to build a sustainable environment and reduce the health risks of groundwater. [ABSTRACT FROM AUTHOR]

This study evaluates the performance of infiltration wells using full-scale field experiments and 3D numerical modeling with GeoStudio SEEP/W, focusing on sandy soils. Infiltration wells are essential for improving groundwater recharge, lowering urban runoff, and controlling flood risks. However, differences in soil qualities and external environmental circumstances are the leading causes of the frequent disparities between modeled predictions and field observations. The process consists of two primary steps: numerical modeling to duplicate these conditions and compare results and field testing to measure the amount of water absorbed by the soil during an hour. Detailed records of the attributes of the soil, including water content and grain-size distribution, as well as hydraulic conductivity, were made. The field results indicate a logarithmic increase in water infiltration, reflecting rapid initial infiltration that gradually plateaued, demonstrating the changes in soil saturation. However, the numerical model predicted a more consistent infiltration rate across similar intervals, highlighting a significant field-model discrepancy. Comparative analysis revealed that soil heterogeneity and initial moisture content significantly influence the infiltration rates, which were not accounted for entirely in the numerical model. External factors such as atmospheric conditions and unanticipated groundwater movement complicate accurate modeling. Enhancement of model parameters, incorporating comprehensive soil data, and integration of laboratory experiments are suggested to bridge the gaps between the numerical and field measurements. Furthermore, this research contributes to the sustainable management of groundwater resources by optimizing the design and implementation of infiltration wells, providing valuable insights for both practical implications and academic endeavors. [ABSTRACT FROM AUTHOR]

This study examines the impacts of climate change on groundwater quality and recharge in the Tensift Basin, focusing on the Haouz, Bahira, and Essaouira aquifers. Analysis of data collected from 2013 to 2017 reveals significant spatial and temporal variability in water quality, driven by both natural and anthropogenic factors. In the Haouz aquifer, the proportion of water classified as "Excellent" quality dropped from 7% in March 2013 to 0% by July 2017, while "Good" quality water increased from 47% to 60%. The Bahira aquifer consistently showed 45% to 64% of water samples falling under "Average" quality, with occasional increases in "Poor" quality water up to 45%. The Essaouira aquifer exhibited a consistent presence of "Average" quality water at 75%, with "Poor" quality water observed in some instances. These trends indicate a decline in water quality exacerbated by climate change effects such as increased evapotranspiration, altered precipitation patterns, and rising sea levels. The study underscores the urgent need for comprehensive groundwater management strategies, including improved monitoring, sustainable water use practices, and adaptive measures to mitigate the impacts of climate change. These efforts are crucial for ensuring safe drinking water, protecting public health, and sustaining groundwater resources in the region. [ABSTRACT FROM AUTHOR]

Groundwater depletion and water scarcity are pressing issues in water-limited regions worldwide, including Pakistan, where it ranks as the third-largest user of groundwater. Lahore, Pakistan, grapples with severe groundwater depletion due to factors like population growth and increased agricultural land use. This study aims to address the lack of comprehensive groundwater availability data in Lahore's semi-arid region by employing GIS techniques and remote sensing data. Various parameters, including Land Use and Land Cover (LULC), Rainfall, Drainage Density (DD), Water Depth, Soil Type, Slope, Population Density, Road Density, Normalized Difference Vegetation Index (NDVI), Normalized Difference Built-Up Index (NDBI), Moisture Stress Index (MSI), Water Vegetation Water Index (WVWI), and Land Surface Temperature (LST), are considered. Thematic layers of these parameters are assigned different weights based on previous literature, reclassified, and superimposed in weighted overlay tool to develop a groundwater potential zones index map for Lahore. The groundwater recharge potential zones are categorized into five classes: Extremely Bad, Bad, Mediocre, Good, and Extremely Good. The groundwater potential zone index (GWPZI) map of Lahore reveals that the majority falls within the Bad to Mediocre recharge potential zones, covering 33% and 28% of the total land area in Lahore, respectively. Additionally, 14% of the total area falls under the category of Extremely Bad recharge potential zones, while Good to Extremely Good areas cover 19% and 6%, respectively. By providing policymakers and water supply authorities with valuable insights, this study underscores the significance of GIS techniques in groundwater management. Implementing the findings can aid in addressing Lahore's groundwater challenges and formulating sustainable water management strategies for the city's future. [ABSTRACT FROM AUTHOR]