Aquifer Recharge Research Articles

Hydraulic characterization of Pwales aquifer in Malta Island preparatory for planning managed aquifer recharge (MAR) pilot plant

Whitin the aim to reduce the water demand by increasing water use efficiency and providing alternative water resources, and mainly to meet the demand of good quality irrigation water for agriculture, the Energy and Water Agency of Malta is planning to develop a Managed Aquifer Recharge pilot plant in Pwales Valley to improve the quantitative and qualitative status of the groundwater body. For this reason a detailed hydraulic characterization of the valley was carried out. Specifically, hydraulic properties of the rocks that constitute strata atop of the Pwales aquifer were determined by means of both laboratory measurements on samples and field test carried out in the studied area. The water retention and hydraulic conductivity functions, which relate the matric potential, ψ, and hydraulic conductivity, K, to the water content, θ, respectively, were measured using three experimental methods because each of them allows to obtain data points in a specific wet range. The water retention and hydraulic conductivity functions were measured on samples extracted from blocks of Upper Coralline Limestone formation, that hosts the aquifer, collected in three different quarries: Ghian Tuffieha, Mellieha and San Martin areas. The measured water retention and hydraulic conductivity data were fitted with LABROS SoilView Analysis software that allows to describe the functions and obtain the parameters which are crucial for modelling the water flow and transport processes in the critical zone. In addition, large ring infiltrometer test was carried out to determine the field saturated hydraulic conductivity, Kfs, and the average infiltration rate. Knowledge of the hydraulic characteristics of the Upper Coralline Limestone, completely missing in the scientific literature, allows developing a local groundwater-flow numerical model in order to better describe and understand how the water flows from the soil to the groundwater of the valley and visualize different environmental scenarios such as the potential effects of Managed Aquifer Recharge plant in the Pwales Coastal Groundwater Body.

Groundwater development and management constraints in drought prone Chiredzi and Zvishavane Districts, Zimbabwe

Communities in drought-prone areas continued to fall into new vulnerability traps due to increasing water demand and stress. The study assessed groundwater development and management constraints in the Chiredzi and Zvishavane districts of Zimbabwe. Groundwater development and management activities implemented in the study area were supported by the Government of Zimbabwe, development partners, humanitarian agencies, private sector corporate social responsibility, and individual households. Interpretivism and realism philosophical positionalities were employed in the study. Whilst interpretivism’s inductive approach enabled an in-depth qualitative methodology and understanding of the groundwater constraints, the direct realism provided quantitatively driven scientific and statistical data to answer the research questions exhaustively. Quantitative data was gathered through a household questionnaire administered to randomly selected respondents. Qualitative data was gathered using focus group discussions, key informant interviews, direct field observations and measurements. Respondents to the key informant interview were drawn from district-level government officials, local authorities, traditional leaders, village pump minders and water point committee members.Due to climate change, communities have experienced an increase in the decline in groundwater levels during the dry season evidenced by demand surpassing supply. Temperature increase and rainfall decline experienced by 97%, and 73% of respondents from Chiredzi and Zvishavane districts, respectively, resulted in increased withdrawal and reduced groundwater recharge. Participants revealed that groundwater withdrawal is on the increase while recharge is declining as evidenced by the increase in conflicts at waterpoints. The 85% coverage by low groundwater-yielding basement hydrogeological formation suggested a slight reduction in groundwater recharge due to reduced rainfall and increased community vulnerability to drought. Village Pump Minders and Water Point Committees experienced operational challenges that affected the maintenance of groundwater sources. This was mainly due to the incapacitation of local institutions in terms of financial resources, equipment, and skills. The study recommends a groundwater replenishment model to improve groundwater aquifer recharge. Strengthening of local institutions improves the management of groundwater using integrated water resources management (IWRM) framework that promotes coordination between competing uses.

Enhancing groundwater recharge in drinking water protection zones in Flanders (Belgium): A novel approach to assess stormwater managed aquifer recharge potential

Study regionFlanders (Belgium) Study focusStormwater infiltration for managed aquifer recharge is increasingly recognized as a drought adaptation measure. Given the high degree of urbanization and imperviousness, stormwater infiltration has significant potential in Flanders (Belgium). This research presents a novel approach to quantify stormwater availability and its potential to enhance groundwater recharge. Stormwater volumes available for recharge are calculated based on the imperviousness level, yearly average precipitation volumes, and runoff coefficients. This study focuses on groundwater protection zones around drinking water wells to assess the role of increased infiltration for sustainable drinking water production. Calculated potential stormwater volumes for recharge are compared to natural groundwater recharge and pumping volumes for drinking water production to quantify the potential significance of stormwater infiltration for aquifer recharge. New hydrological insights for the regionResults show a high potential for stormwater infiltration in Flemish protection zones with an average of 17% (7%-33%) additional groundwater recharge from stormwater infiltration. Additionally, stormwater recharge could potentially compensate for 19% (8%-37%) of abstracted drinking water production from phreatic aquifers. Locally, higher groundwater recharge potentials were calculated, especially in protection zones around the city of Leuven. Therefore, stormwater harvesting for infiltration and groundwater recharge should be further encouraged throughout the region, with special attention to urban areas. However, further research is needed on stormwater quality to assess groundwater quality risks in this water quantity-quality balancing exercise.

Managed aquifer recharge as a strategy to redistribute excess surface flow to baseflow in snowmelt hydrologic regimes

Water management in snowmelt hydrologic regimes, characterized by large annual fluctuations in stream flow driven by seasonal snow melt, faces the challenge of highly variable supply that often does not align with timing of demand. Climate change may exacerbate management challenges by significantly reducing snowpack or shifting snow melt earlier. Here, managed aquifer recharge (MAR) is evaluated as a potential strategy to reallocate excess early-season stream flow to time periods when less surface water is available. This strategy differs from traditional MAR, where the goal is to minimize loss to surface water. We assess how to site MAR operations such that groundwater recharge flows back to the surface water system in a lagged manor to benefit water management objectives, which we term “enhanced baseflow.” We use a regional groundwater model for the Treasure Valley aquifer located in southwestern Idaho, United States to demonstrate a generalizable approach using regional groundwater models as tools to identify favorable baseflow enhancement locations. Hypothetical MAR is simulated at 197 candidate locations, which are then evaluated for how effectively they meet potential management objectives. In addition to demonstrating the modeling and evaluation approach, we discuss lessons learned from applying a pre-existing regional groundwater model to MAR for enhanced baseflow and also describe important considerations, such as the physical and institutional availability of surface flows and specific management objectives, when assessing regional and site-specific suitability of MAR for enhanced baseflow as a potential management strategy.

Application of the fuzzy analytic hierarchy process for water resources in the Wadi AlHasa catchment, Jordan

This article introduces a groundwater vulnerability assessment model that utilises the fuzzy analytic hierarchy process (FAHP) in the Wadi AlHasa catchment, Jordan. The assessment takes into account both geomorphological and hydrogeological variables, employing a comprehensive methodology that integrates various parameters. To evaluate the catchment, the study employs remote sensing and Geographic Information System (GIS) techniques. The analysis of the digital elevation model enables the creation of a map illustrating the diverse geomorphology of the catchment. This geomorphology significantly influences drainage density, direction, and the spatial distribution and intensity of flash flood events. Moreover, the study develops and maps a fuzzy FAHP DRASTIC vulnerability index, which proves to be a valuable tool for assessing the susceptibility of groundwater resources to contamination. The unique feature of the index is its ability to incorporate uncertain or subjective data, providing a means to evaluate the significance of various influencing factors. This information serves as critical support for decision-making and management efforts geared towards safeguarding and enhancing groundwater resources. Within the study area, the DRASTIC vulnerability index values span from 0.08325 to 0.28409, with 18% of the site exhibiting a high vulnerability rate. Additionally, the article implements a managed aquifer recharge model (MAR), with 31% of the area falling into MAR classes. Among these, 22.1% are classified as a high MAR class, while 0.7% belong to a very high MAR class. These findings underscore the feasibility of MAR projects in regions with limited water resources.

ASSESSMENT OF RAINFALL IMPACT ON GROUNDWATER VULNERABILITY FOR AGRICULTURAL PRODUCTION

The research study was conducted in Northern Lake Victoria basin to assess rainfall impact on groundwater as a fresh water source on 30 farms for agricultural production. Depth Aquifer Recharge and Transmissivity (DART) index quantitative method was applied that revealed that rainfall was directly related to groundwater vulnerability index. Positive DART index was realized during long rainfall season between April and June, and during short rainfall season in September and October. The other months had negative values during dry season. DART indices ranged between -8.40 and 2.50 with positive values representing more resilience to negative impact of erratic rainfall. There were two groundwater vulnerability Index Thresholds of -8.40 and -4.80 that marked onset of long and short rainfall seasons respectively. Mann-Kendall trend analysis and t-test performed indicated a downward trend and a significant difference of groundwater vulnerability index values because of seasonal rainfall changes that caused wells to dry up thus increasing water insecurity. The research study results confirmed the severity of rainfall patterns on groundwater recharge that can affect agricultural production and food security to households.

Identifying suitable zones for integrated aquifer recharge and flood control in arid Qatar using GIS-based multi-criteria decision-making

Groundwater resources in arid regions play a vital role in meeting water demands; however, they are facing rapid depletion due to unsustainable exploitation practices, exacerbated by climate change. Floods can present a unique opportunity for restoring groundwater levels and mitigating saltwater intrusion into aquifers. The use of properly managed floodwater for aquifer recharge offers a dual advantage by maximizing the potential of floods as a valuable water resource, while minimizing their negative impacts. In this work, we applied a GIS-based Multi-Criteria Decision-Making (MCDM) method, namely the Analytic Hierarchy Process (AHP), to delineate flood susceptible zones and groundwater recharge zones in Qatar, considering several influential topographical, hydrological, environmental, and anthropological criteria. The maps of flood susceptibility and groundwater recharge potential were validated using recent flooding events and existing recharge wells data, respectively. Sensitivity analysis was conducted on both variables to further assess their accuracy. The overlay analysis of the two validated maps suggests that approximately 64% of the Qatar peninsula presents medium to excellent suitability for aquifer recharge using floodwater. The areas best suited for floodwater-based recharge intervention are the northern and coastal regions of the peninsula, while the urban areas and southwestern area are less suitable. This study provides decision-makers with spatially explicit information on areas in Qatar that can be targeted for aquifer recharge projects using floodwater as well as recommendations on technical, economic, and regulatory considerations that require additional investigation. The approach employed can be effectively applied in similar flood-prone arid regions and is adaptable to diverse contexts.

Temporal and spatial variations of groundwater quantity and quality for drinking and irrigation purposes in the arid and hot weather of Southern Iran

Groundwater provides a reliable water supply of fresh water worldwide for drinking, agricultural, and industrial purposes, especially in areas where surface water is scarce or unreliable, making it an essential resource for human and economic development. Proper management and protection of groundwater resources are crucial to ensure their sustainability and continued contribution to fulfilling the growing water demand worldwide. This study focused on the quantitative and qualitative changes in groundwater in the Kahoorestan Plain, located northwest of the Persian Gulf in southern Iran. The zoning maps produced by Arc GIS revealed a declining trend in the aquifer level and a drop in the groundwater level of 5.24 m over 20 years. The maps of the flow directions also indicated a general trend from the western highlands to the south and southeast regions of the plain. The Piper diagram showed that the predominant hydrochemical facies of the plain area is NaCl. Temporal changes analysis by the Mann-Kendall test revealed that EC, TDS, TH, Na, Mg, Ca, SO4, and Cl parameters have a rising trend in the majority of wells, which attributes to groundwater over-withdrawal, drought, excessive well drilling, and insufficient aquifer recharge. The study’s analysis of the temporal and spatial changes of the water quality index, Schoeller diagram, and Wilcox diagram revealed that the aquifer’s water quality is unsuitable for drinking and irrigation use due to its high salinity and sodium content. The findings underscore the urgency of adopting effective management strategies to ensure the sustainable management of groundwater resources in the region.

Island hydrogeology in the tropics: Constraining a 3D variable-density groundwater flow and solute transport model with geophysics

Saltwater intrusion is the greatest risk to coastal community water supplies where they are dependent on fresh groundwater as the main source of supply. For small, fractured bedrock island aquifers, the fresh groundwater lens dynamics and transition zone geometry are complex. This study investigated the impacts of projected increases in groundwater pumping on a fresh groundwater lens to evaluate changes to the lens geometry and localized up-coning from the deeper, more saline aquifers beneath a small bedrock island in the tropics. A combination of traditional hydrogeological datasets and an airborne electromagnetic survey were used to develop a three-dimensional density-dependent groundwater flow and solute transport model using the SEAWAT code. This investigation represents one of very few studies that have taken such an approach. The model was calibrated using observed groundwater hydraulic heads and chloride concentration data, and calculated chloride values based on bulk conductivity measurements determined from inverted geophysical data. A staged calibration approach was adopted, firstly assessing the time-average lens extent and geometry, and secondly considering the seasonal groundwater level response. In the calibration, the geophysical data helped constrain the lens geometry in the absence of hydraulic head and chloride data. The calibrated model was used to test scenarios where groundwater pumping rates were increased above the current demand of 452 m3 d−1, showing that the lens is likely to be stable, i.e., its available storage is not expected to contract excessively, for extraction rates of up to 3,000 m3 d−1. The combined use of geophysical data and a numerical modeling approach was advantageous in investigating the lens characteristics. It also demonstrated how these techniques can be used together to evaluate coastal water resources and to manage water supply risks for coastal communities. The study demonstrated that the freshwater lens can likely support the freshwater demands of the remote community, and is a preferred option compared with high-cost and more complicated options such as seawater desalination and managed aquifer recharge.

Assessments of groundwater recharge process and residence time using hydrochemical and isotopic tracers under arid climate: Insights from Errachidia basin (Central-East Morocco)

The aquifer systems in the Errachidia basin, located to the south of the High Atlas limestone, are constituted by three superimposed and exploitable aquifers (Senonian, Turonian, and Infracenomanian). These aquifers hold economic significance for the central-east region of Morocco. This area experiences an arid to Saharan climate characterized by low precipitation, high temperatures, and very high evaporation. It is one of the most exposed and vulnerable regions to climate change in Morocco. The low local rainfall cannot explain the recharge of the deep aquifers. However, the significant spring discharges from these aquifers indicate the existence of other recharge contributions.The aim of this study is to elucidate the recharge processes of the Cretaceous aquifers in the investigated basin, clarify hydraulic relationships between them and the Jurassic aquifers of the High Atlas Mountains and estimate the residence time of groundwaters. Water samples from aquifers are collected and analyzed for chemical and isotopic elements. Several statistical methods (SOM, discriminant factorial analysis, CPA) are employed. The results reveal that many samples from different aquifers exhibit clear similarities in chemical characteristics, providing evidence of water transfer between aquifers. Isotopic findings are consistent with chemical characterization and mineralization anomalies.Recharge of the investigated aquifers originates from the Jurassic limestone of the High Atlas Mountains, facilitated by the karstic nature of the Jurassic in contact with the permeable formations of the Cretaceous basin. Age dating results, using 3H and 14C values, confirm that most of the investigated groundwater results from a mixing of old and recent recharges. This process of groundwater renewability is relevant. All the findings are valuable for decision-makers to enhance their understanding of the aquifer system's functioning and inform sustainable management strategies for future sustainability.

Beyond land use planning and ecosystem services assessment with the conservation use potential framework: A study in the Upper Rio das Velhas basin, Brazil

Human actions can damage the ecosystems and affect the services depending on them, with ample detrimental consequences. In earlier studies, the Conservation Use Potential (PCU) framework proved useful in assessing the capacity for aquifer recharge, suitable land uses and resistance to erosion at the river basin scale. On the other hand, the joint analysis of PCU and land uses allowed identifying the adequacy of current uses in relation to suitability (natural uses) in various basins. This was especially useful from the management perspective in basins with environmental conflicts, where current uses differed from suitability, because the PCU indicated how and where the conflicts should be mitigated. Besides the use as management tool, the PCU has potential to shed light over environmental issues such as ecosystem services, but that was not tempted so far. The aim of this work was therefore to bridge that knowledge gap and frame the PCU's application from the standpoint of Ecosystem Services (ES) assessment. We demonstrated how the PCU could be used to improve provision (recharge), support (sustainable agriculture) and regulation (resistance to erosion) services in a specific basin with land use conflicts (the Upper Rio das Velhas basin, located in Minas Gerais, Brazil), through the planning of suitable uses. It was noted that the studied basin is mostly composed of Very Low, Low and Medium potentials. These classes occur because steep slopes, fragile soils and lithologies with high denudation potential and low nutrient supply dominate in the basin. On the other hand, urban sprawl has a negative impact on all ES, while maintaining agricultural areas with appropriate management can effectively regulate erosion. As per the current results, the premise of using the PCU as joint management-environmental tool was fully accomplished, and is recommended a basis for public policy design and implementation in Brazil and elsewhere.

AI-Driven Groundwater Level Enhancement System using Advanced Prediction Algorithms

This research focuses on predicting water sources in various areas by analyzing historical data on groundwater levels, rainfall, and borewells. The study explores the relationships between groundwater levels and environmental factors, emphasizing the influence of rainfall on aquifer recharge. Borewell data, including depth and water quality, is incorporated to identify potential water sources. The research involves data cleaning, exploratory analysis, and machine learning to predict groundwater levels based on diverse features such as rainfall patterns and geographical characteristics. Spatial analysis using GIS tools visualizes the distribution of groundwater levels and rainfall. The model's performance is evaluated, considering metrics and local hydrogeological conditions, with an emphasis on integrating borewell data. Continuous monitoring and updates ensure the model's ongoing relevance. This integrated approach aims to provide insights for sustainable water resource management, assisting decision-makers in planning water sources in diverse areas.

Transport, dispersion, and degradation of nonpoint source contaminants during flood‐managed aquifer recharge

AbstractIn water‐stressed regions of the world, the inundation of working landscapes to replenish aquifers—known as flood‐managed aquifer recharge (flood‐MAR)—has become a valuable tool for sustainable groundwater management. Due to their diverse land use histories, however, many potential recharge sites host nonpoint source contaminants (such as salts, pesticides, and fertilizers) within the vadose zone that may flush to groundwater during recharge operations. To identify the controls on contaminant migration, we perform stochastic simulations of flood‐MAR through a heterogeneous alluvial aquifer and apply transient particle tracking to evaluate conservative and reactive contaminant transport over 80 years of recharge operations. With semi‐annual recharge events, the water table begins to rise 0.13–1.84 years after the first inundation event while solutes take much longer (11 to 80 years) to transit the 45‐m thick unsaturated zone. We derive a parametric expression for the ratio of celerity (or rate of pressure transmission) to velocity of the flood‐MAR wetting front and show that this simplified expression agrees with values calculated from heterogeneous model simulations. Slow solute velocities (0.25–1.75 m year−1) allow for significant contaminant removal through denitrification, but the contaminant plume experiences minimal dispersion or dilution over this time, reaching the water table as a sharp front. Our results suggest that minimizing groundwater velocity and maximizing groundwater celerity during flood‐MAR should optimize increases in water supply while limiting water quality degradation.

Resilient agriculture: water management for climate change adaptation in Lower Saxony

Abstract Climate change has increased the intensity, frequency and duration of heatwaves and droughts in Europe turning water management into an even more complicated issue. Because water is a fundamental resource for agriculture, water management has to be addressed with climate change adaptation. While stakeholders in Lower Saxony are aware of adaptation measures they could implement to dampen the effects of climate change, evidence of the effectiveness of adaptation measures at a local scale is still missing. An analysis of adaptation measures using a new hydrological model was performed to test four adaptation measures suggested by stakeholders. Changing crops has the strongest effect followed by improving irrigation efficiency, humification and, finally, artificial aquifer recharge. If crops are changed, irrigation water demand and energy consumption could be reduced by up to 20.7%, costs could be reduced in 19.1%, the aquifer level could rise up to 284.85 mm and emissions could be reduced by 26.6% by the end of the century. Artificial recharge proved to be an inadequate method for the region as it does not impact the irrigation water demand, and an insufficient amount of water is available to have a substantial effect on the aquifer.

Recharge Assessment in Greek Karst Systems: Methodological Considerations and Implications

The recharge of karst aquifers is significant for the effective management of groundwater resources, and its estimation should be tailored to accommodate their specific hydrogeological characteristics. This study provides a two-step methodological approach for the determination of karst aquifer recharge. Initially, mean annual recharge rates were estimated in the karst system of Ziria (Southern Greece) utilizing the APLIS and modified APLIS methods in order to decipher which was the most suitable version for recharge assessments. The results indicated similar mean recharge rate values at 42.7% and 41.4%, respectively, but significant differences in the spatial distribution. The modified methodology emerged as a more accurate and realistic approach, mainly due to the incorporation of permeability assessments. The final phase of the methodological approach involved the application of modified APLIS in two additional karst hydrosystems, Planitero and Xiromero, while a quantitative cross-comparison of the recharge rates was obtained for a deeper understanding of the factors controlling the groundwater recharge process. In Ziria, recharge rates exhibit a relatively uniform distribution throughout the area, with a median value of 46.7%. Conversely, in Planitero, High recharge rates (60–80%) occupy 56.8% of the surface, while in Xiromero, Moderate recharge rates (40–60%) dominate, representing 53.4% of the land coverage. These variations underscore the spatial heterogeneity of recharge within the karst systems, highlighting the importance of considering local geological and hydrological conditions in its assessments. The methodological approach of this study is flexible and can be adapted to different karst sites for the determination of recharge regimes, contributing to the alleviation of the groundwater depletion issue.

Developments and applications of the HYDRUS computer software packages since 2016

AbstractThe HYDRUS codes have become standard tools for addressing many soil, agricultural, environmental, and hydrological problems requiring the evaluation of various subsurface physical, chemical, and biological processes. There are now many thousands of HYDRUS users worldwide, with thousands of applications of the HYDRUS models appearing in the peer‐reviewed literature. In this manuscript, we provide an overview of the capabilities of the most recent Version 5 of HYDRUS, focusing primarily on features implemented since 2016. We briefly describe the standard HYDRUS model and its standard and nonstandard specialized add‐on modules that significantly expand the capabilities of the software packages. The standard add‐on modules include HPx, UNSATCHEM, Wetland, Furrow, PFAS, COSMIC, DPU, SLOPE Cube, and Particle Tracking. Recent developments of the HYDRUS Package for MODFLOW are also described, along with additional capabilities incorporated into the graphical user interface supporting HYDRUS. Also discussed are new or improved options to simulate the fate and transport of environmental isotopes, multi‐cropping systems, compensated root water uptake, and hydraulic redistribution within the rootzone, which will be implemented in upcoming add‐on modules. Another objective is to review selected applications of the HYDRUS models, such as evaluations of various irrigation, low‐impact development (LID), and managed aquifer recharge (MAR) schemes.

Quantifying water loss in leaky micro-dam reservoir through water balance analysis and high-resolution water level data modeling

Abstract This study aimed to assess the runoff, recharge, and response of a shallow aquifer to leakage from the Arato micro-dam reservoir (MDR). The assessment was conducted using the Soil Conservation Service Curve Number (SCS-CN), soil moisture balance (SMB), and diver (automatic data logger) measurements in both the MDR and a shallow hand-dug well. Recharge was estimated using the chloride mass balance (CMB) and water table fluctuation (WTF) methods. The results revealed that the annual runoff from the catchment was 48.8 mm, which accounted for approximately 0.71 million m3. The yearly groundwater recharge was estimated to be 104, 92.8, and 100 mm using the SMB, CMB, and WTF methods, respectively. Furthermore, the water balance model of the Arato MDR indicated a leakage rate of 13.2 mm/day. It is noteworthy that the estimated leakage exceeded the seepage initially anticipated during the project's design phase (9,965 m3/year). This research project highlights the significance of utilizing local climatic and physical data from the specific watershed under investigation when planning reservoirs and other water resources. It also underscores the importance of conducting thorough site investigations to accurately quantify hydraulic conductivity for leakage estimation purposes.

Quantitative Groundwater Modelling under Data Scarcity: The Example of the Wadi El Bey Coastal Aquifer (Tunisia)

The Grombalia aquifer constitutes a complex aquifer system formed by shallow, unconfined, semi-deep, and deep aquifers at different exploitation levels. In this study, we focused on the upper aquifer, the Wadi El Bey coastal aquifer. To assess natural aquifer recharge, we used a novel physiography-based method that uses soil texture-dependent potential infiltration coefficients and monthly rainfall data. The developed transient flow model was then applied to compute the temporal variation in the groundwater level in 34 observation wells from 1973 to 2020, taking into account the time series of spatially variable groundwater recharge, artificial groundwater recharge from 5 surface infiltration basins, pumping rates on 740 wells, and internal prescribed head cells to mimic water exchange between the wadis and aquifer. The quantified deviations in the computed hydraulic heads from measured water levels are acceptable because the database used to construct a scientifically sound and reliable groundwater model was limited. Further work is required to collect field data to quantitatively assess the local inflow and outflow rates between surface water and groundwater. The simulation of 12 climate scenarios highlighted a bi-structured north‒south behaviour in the hydraulic heads: an increase in the north and a depletion in the south. A further increase in the pumping rate would, thus, be severe for the southern part of the Wadi El Bey aquifer.

Groundwater Hydraulics in Increased Spring Discharge following Earthquakes: Some Applications and Considerations

Earthquakes often entail alterations in the groundwater flow regime, in the phreatic level, surges and losses of springs, and the discharge in brooks. A variety of theoretical approaches attempt to elucidate the post-earthquake effects on spring discharge. This study adopts a conceptual approach, primarily presenting diverse methods to estimate water released by earthquakes involving calculations of discharge surpluses in springs. This study delves into refined techniques rooted in groundwater hydraulics, displaying applications of analytical and simulation methodologies to quantify earthquake-induced groundwater discharge in springs. This research investigates springs as natural indicators and applies mathematical precipitation–runoff models, particularly the CREC model, to simulate hydrographs in post-earthquake scenarios. We apply analytical procedures or mathematical simulation techniques employed in groundwater hydraulics for natural aquifer recharge calculations. Firstly, we briefly describe the methods based on the analysis of depletion curves of hydrographs in spring discharge. Additionally, specific mathematical rainfall–runoff models used to simulate hydrographs of karstic springs, along with derived analytical approximations, are adapted for this scenario. These hydraulic calculations involve the depletion coefficient and hydrodynamic volumes of aquifers, parameters that reveal certain aspects of the relation between groundwater and earthquakes. Three main features are: (a) Acknowledging faults as the primary geological structures in transmitting pore pressures due to earthquakes. Thus, for large and deep faults, which connect the ground surface with the Earth’s crust bottom—where earthquakes trigger—the depletion coefficient, α, usually reaches high values (α = 0.1 days−1). Therefore, these faults become more sensitive to pore pressure than other lithologies. (b) Elucidating the mechanisms of permeability enhancement caused by earthquakes. (c) Highlighting the substantial volumes in motion within the Earth’s interior, which, for instance, could constitute a significant source for the origin of mineral deposits. Mathematical calculations enable the determination of the volume of mobilized water that can be discharged by gravity in each earthquake. This, along with its recurrence, justifies the substantial mineralization volumes.

Managed aquifer recharge site suitability analysis in the Nabogo Basin of Ghana using GIS and Monte Carlo simulation-aided analytic hierarchy process

Managed aquifer recharge site suitability analysis in the Nabogo Basin of Ghana using GIS and Monte Carlo simulation-aided analytic hierarchy process