Artificial Groundwater Recharge Research Articles

Transport and interaction of cadmium and active sludge extracellular polymeric substances in saturated sand influenced by ionic strength and composition.

Artificial groundwater recharge with reclaimed water (secondary effluent from wastewater treatment plants) has become an important approach to solving water scarcity worldwide. Microorganisms in activated sludge can secrete many extracellular polymeric substances (EPS). However, information on the impact of EPS on the movement of heavy metals in porous media and their environmental effects on underground networks is limited. To assess this risk, we extracted EPS from the aerobic section of a wastewater treatment plant using hot sodium hydroxide and conducted experiments using one-dimensional sand columns to investigate how ion composition and strength affect the movement and interaction of cadmium (Cd) and EPS in porous media. The results showed that EPS facilitated Cd migration in porous media. Sodium (Na) and calcium (Ca) ions promoted the migration of Cd in porous media and EPS-Cd complexation. The effect of Ca was more significant than that of Na. As the Na adsorption ratio increased, the migration ability of Cd in porous media and the complexation ability of EPS with Cd decreased. Therefore, when estimating the migration of EPS and Cd in subsurface environments, careful consideration should be given to prevent the risk of groundwater pollution.

Mapping Ground Water Potential Recharge Zones of Wadi Al-Batin Alluvial Fan, Using Remote Sensing and GIS Techniques, Southwestern Iraq

Groundwater potential recharge (GWPR) zones are an important process in managing water resources. Six thematic layers were used to produce GWPR mapping for Wadi Al-Batin alluvial fan, Southwestern Iraq with GIS environment and analytical hierarchical process (AHP), including geology, lineaments density, slope gradient, drainage density, soil, and slope aspect. Based on the importance, the thematic layers are ranked, which control the GWPR. Drainage density, lineament density, slope aspect, and slope gradient maps are classified into five classes, whereas, geology and soil are classified into six classes. The classes are weighted based on the magnitude of groundwater recharge potential. The AHP technique divides the entire into three zones based on GWPR values: high, moderate, and low. The final GWPR map demonstrated that the western and northwestern parts of the alluvial fan have greater groundwater recharge potentials with 70% of the total area due to the increase in the infiltration rates as a result of the gravely and sandy soils besides the agricultural land use in the present areas. However, the other part of the fan ranged between moderate and low with 25% and 5% of the total area, indicating suitable zones for groundwater artificial recharge processes.

Hydrological Inferences of Morphometric Parameters for Management of River Sub-basin in Semi-arid Tropics of India using Geospatial Technique

The runoff and sediment produced from a river basin due to effective precipitation depends on the characteristics of its catchment. The catchment characteristic is site-specific and varies from basin to basin. It depends upon the topographic characteristics, climatic parameters, soil properties, geology, and human-induced activities of the catchment. Knowledge of these factors is essential for sustainable management of natural resources, i.e. soil and water and site-specific conservation measures of the basin or watershed. Morphometric parameters of the basin truly reflect the combination of all characteristics, and this is one of the major indicators for the hydrological behaviour of any watershed or catchment. For the present study, Pairi River sub-basin, situated between 81°51'58.7"- 82°26'16.04" E longitude to 19°55'51.9"- 20°55'6.9" N latitude, has been considered for the morphometric analysis using geospatial technique . Results of morphometric analysis revealed that the Pairi sub-basin has seventh order drainage network with a dendritic pattern. The dendritic drainage pattern of the subbasin shows that the basin has homogeneous lithology and a lack of structural control. The drainage density and stream frequency indicates that the sub-basin has a gentle slope and good permeability of sub-surface material. So, this sub-basin is suitable for constructing artificial groundwater recharge structures to improve the groundwater resource. The length of overland flow revealed that surface runoff may reach the stream more quickly within the sub-basin. The bifurcation ratio varies different successive stream orders. The mean bifurcation ratio is low, indicating that the geologic structure does not distort the drainage pattern and produces low to moderate peak flow in the subbasin. The shape parameters such as form factor, circulatory ratioand elongation ratio indicate that the sub-basin is elongated in shape, high infiltration capacity, and flatter hydrograph with low to moderate runoff. This study can be useful for developing and managing natural resources of the Pairi sub-basin, like site-specific soil and water conservation measures such as check dam, percolation tank, water harvesting structure and development and management of groundwater, etc

Network dynamics for modelling artificial groundwater recharge by a cluster of infiltration basins

AbstractIn this paper we propose a simple approach for modelling the functioning of a cluster of interconnected infiltration basins: such a modelling is crucial for correctly managing artificial aquifer recharge. We model and dynamically quantify the flow from the bottom of each basin, towards the outer walls of the cluster, and between adjacent basins: as a result of this modelling, saturated hydraulic conductivity parameters are estimated. This goal is accomplished simply by using mass balance arguments and Darcy's law, considering only water levels data and the total water inflow daily bestowed to the trenches; by using a declipping technique, automated recorded data are suitably filtered; then, from these data, an efficient algorithm is implemented for determining which basin is instantaneously fed. This approach can be used for managing the efficiency and performance of such facilities over time, and it can be easily generalized. The model is tested over a real‐life site in Castellana Grotte (Southeastern Italy), where an infiltration basins cluster is used as final receptor of the effluents from a tertiary treatment wastewater plant.Novelty and International Appeal StatementWe propose a simple approach for modelling the functioning of a cluster of interconnected infiltration basins. By a dynamical systems approach, we model the flow from the bottom of each basin, towards outer walls of the cluster, and between adjacent basins: as a result, saturated hydraulic conductivity parameters are estimated.

Sub-Watershed Prioritization of Kariangote River in Kerala Based on Drainage Morphometry and Geomorphology – A Remote Sensing and GIS Approach

Objectives: This article examines the geohydrological behaviour of the Kariangote watershed and prioritizes its subwatersheds based on groundwater presence. Methods: Remote sensing and GIS techniques were used to study the morphometric and geomorphologic characteristic of the watershed. Six sub-watersheds were identified, and various morphometric and geomorphic parameters were calculated. Based on the relative importance to groundwater occurrence, sub-watersheds were prioritized by giving suitable weightage to morphometric and geomorphological units. Findings: Sub-watershed IV is the most deficit one and is given priority followed by III the next, V, II, I, and VI. Sub-watershed VI is with surplus groundwater and is given the last priority. Novelty: Higher priority should be given to conservation practices in sub-watersheds to prevent surface runoff and soil erosion and to increase groundwater levels. Sub-watersheds with highly permeable subsurface formation could be suggested for rainwater harvesting and artificial recharge of groundwater. Planning further groundwater development projects and managing watersheds would be aided by this study. Keywords: Morphometry; Coastal Alluvium; Flood Plain; Groundwater; Prioritization

Using Artificial Intelligence to Identify Suitable Artificial Groundwater Recharge Areas for the Iranshahr Basin

A water supply is vital for preserving usual human living standards, industrial development, and agricultural growth. Scarce water supplies and unplanned urbanization are the primary impediments to results in dry environments. Locating suitable sites for artificial groundwater recharge (AGR) could be a strategic priority for countries to recharge groundwater. Recent advances in machine learning (ML) techniques provide valuable tools for producing an AGR site suitability map (AGRSSM). This research developed an ML algorithm to identify the most appropriate location for AGR in Iranshahr, one of the major districts in the East of Iran characterized by severe drought and excessive groundwater consumption. The area’s undue reliance on groundwater resources has resulted in aquifer depletion and socioeconomic problems. Nine digitized and georeferenced data layers have been considered for preparing the AGRSSM, including precipitation, slope, geology, unsaturated zone thickness, land use, distance from the main rivers, precipitation, water quality, and transmissivity of soil. The developed AGRSSM was trained and validated using 1000 randomly selected points across the study area with an accuracy of 97%. By comparing the results of the proposed sites with those of other methods, it was discovered that the artificial intelligence method could accurately determine artificial recharge sites. In summary, this study uses a novel approach to identify optimal AGR sites using machine learning algorithms. Our findings have practical implications for policymakers and water resource managers looking to address the problem of groundwater depletion in Iranshahr and other regions facing similar challenges. Future research in this area could explore the applicability of our approach to other regions and examine the potential economic benefits of using AGR to recharge groundwater.

A hybrid MCDA approach for delineating sites suitable for artificial groundwater recharge using drywells

Artificial recharge in urban aquifers is of vital importance due to the increase in urbanization resulting in a reduction in natural recharge along with groundwater overdraft in many regions across the globe. Despite existing several managed aquifer recharge (MAR) technologies, land availability for installation and limited municipal budget restrict their usage, especially in urbanized areas. Hence, drywells were introduced as a vadose zone recharge (VZR) facilitating the recharge of stressed aquifers with low land impact and financial resources. Also, identifying suitable sites for drywell implementation is complex due to the number of driving factors involved. In this paper, the integrated fuzzy analytical hierarchy process (FAHP) and technique for order of preference by similarity to ideal solution (TOPSIS) approach was proposed to delineate a site suitability map for artificial groundwater recharge using drywells in the city of Kayseri, Turkey. Nine decision criteria were selected and the weights of each (sub-) criterion were determined through the FAHP. The results indicated that hydraulic conductivity, depth to groundwater, soil texture, and land use/land cover were the most determining criteria with 33.9%, 17.8%, 11.2%, and 10.1% of weights, respectively. Also, the stability and robustness of the criteria weights attained were validated through sensitivity analysis within the FAHP framework. Finally, the study area was divided into 54 sub-regions based on the road-network and the TOPSIS was applied to prioritize the sub-regions to help identify promising areas for the vadose zone wells construction. Here, a similar approach can be adopted by municipalities lacking guidelines and standards for sitting drywells.

Effect of biofilms on the clogging mechanisms of suspended particles in porous media during artificial recharge

Artificial recharge of groundwater is an effective technology for solving the shortage of water resources. The clogging of porous media is a bottleneck that limits the application of this technology. In this study, percolation experiments in sand columns were conducted to investigate the influence of different types of biofilms on the deposition of suspended particles and clogging evolution during artificial recharge. A unique aspect of this study is the consideration of biofilms coated on porous media when the clogging mechanisms of suspended particles in porous media are explored. At the end of the recharge process, the relative hydraulic conductivity (K’) of the porous media in descending order was Pseudomonas aeruginosa experimental group (PA) > Bacillus subtilis experimental group (BS) > mixed microbial consortium experimental group (MC) > suspended particle only group (SP). The suspended particles in SP- moved more deeply into the sand column than those in BS, PA, and MC. Electron microscopy, high-throughput sequencing, and confocal laser scanning microscopy were used to identify the mechanisms governing clogging evolution under the influence of biofilm existence. The presence of a biofilm not only alters the surface charge and physical roughness of the porous media, but also affects the electrostatic interaction between the porous media and suspended particles. Biofilms combine tightly with suspended particles by binding and adhesion, which can form tight biofilm-particle aggregations. Compared with deposition of particle-only in SP, the biofilm-particle aggregations on the surface of the porous media are more firm. The biofilm coated on the surface of porous media occupied the pore vacancy and narrowed the void space compared with that in clean sand, which induced physical straining. As the thickness of biofilm coated on the sand surface increased, the more suspended particles were deposited on the sand surface in PA. These findings provide insights into clogging under the influence of biofilms and have implications for future field-based artificial recharge.

Threshold Recognition of Water Turbidity for Clogging Prevention during Groundwater Recharge Using Secondary Effluent from Wastewater Treatment Plant

The recharge efficiency during artificial groundwater recharge (AGR) is reduced primarily by clogging that is triggered by suspended particles. However, there are loopholes in the current standards of recharge-water quality for clogging control during AGR, and the threshold values of turbidity to prevent clogging have not been reasonably determined. In this study, secondary effluents from wastewater treatment plants (WWTPs) were injected into saturated sand columns to simulate the process of AGR. Batch experiments under different turbidity conditions were conducted, and the numerical modeling of particle transport and deposition was performed to assess the clogging processes. Theories of single-collector contact and interfacial interaction energy were applied to elucidate possible microcosmic mechanisms. The results showed that the diluted secondary effluent (SE) with turbidities of 0.540 ± 0.050, 1.09 ± 0.050, and 1.84 ± 0.060 NTU caused considerable clogging in the porous media, which decreased the relative hydraulic conductivities (K/K0) by 13.2%, 17.6%, and 83.6%, respectively. The filtered SE with a turbidity of 0.160 NTU did not cause clogging, and K/K0 was reduced by only 1.70%. The clogging was attributed to the deposition of suspended particles in the sand matrix because they have a high collision efficiency (0.007–1.98) and attachment efficiency (0.029–0.589 kBT). Finally, this paper recommends that the turbidity of the recharge water should not exceed 0.500 NTU during AGR practices.

Experimental Study of the Microscopic Visualization of Gas Clogging during Groundwater Recharge

Clogging is one of the most important factors that restricts the development and popularization of artificial groundwater recharge technology. Gas clogging is an important but often overlooked form of clogging. In this study, a high-speed image acquisition system was used to obtain high-resolution images of the migration of water and gas in the pore. The bypass flow, trapped bubbles in the H-shaped pore channel, blind end, and corner of the pore were directly observed and their clogging mechanisms were analyzed. The influences of the pore structure and gas content on the degree of gas clogging were quantified. The pore–throat size has a certain controlling effect on the movement of the gas and liquid phases. As the diameter of the pore–throat increases, the clogging effect of the gas decreases, and the relative permeability of the water (krw) increases. The pore–throat ratio exhibits a negative correlation with the relative permeability of the liquid phase, and the pore–throat sorting coefficient exhibits a positive correlation with krw. As the gas content increases, the degree of gas clogging increases, and the effect is more significant at low gas-to-liquid ratios (<1:2). These results provide theoretical support for the scientific quantitative evaluation and prediction of the occurrence of gas clogging in groundwater recharge projects.

Delineation and Prioritisation of Groundwater Recharge Areas in the State of Tamil Nadu using Geographical Information System

Delineation and prioritisation of suitable areas for artificial groundwater recharging (AGR) in the state of Tamil Nadu was carried out in the present study. Soil properties namely, soil drainage and land capability class, and geology of the aquifer were identified as spatial parameters that influence the AGR. Weights of 25, 25, and 50% were given to the soil drainage, land capability class, and geology of the aquifer, respectively. Variability within a specific theme was considered by assigning appropriate score to the subtheme. The depth of water table, in addition to soil drainage and land capability class, and geology of the aquifer, was used to decide the priority area of the AGR. Prioritised areas were divided into different rainfall zones as priority first (PR1) and priority second (PR2), which was found to be 14.29% and 38.18% of total area of the state, respectively. Considering bi-modal nature of rainfall in Tamil Nadu, the estimated numbers of percolation pond and check dam were worked out as 6,118 and 15,730 for PR1 areas; while numbers of percolation pond and check dam were worked out as 16,468 and 42,350 for PR2 areas, respectively. The results of this study can help state departments to implement the AGR scheme.

Simulation and Prediction of Groundwater Dynamics in Nagarjuna Sagar Right Canal (NSRC) Command for Normal and Extreme Groundwater Recharge Conditions

Groundwater Modeling is the best tool to optimize the different combinations and to select the best combination for sustainable groundwater management. Using computer models, best solution or scenario can optimize by creating model with real conditions. In this study, computer model Visual MODFLOW was applied to Nagarjuna Sagar Right Canal Command area to simulate the groundwater dynamics. The net area irrigated under Nagarjuna Sagar Right Canal is 4.75 lakh ha. The aquifer properties of various layers and boundary conditions were fed in to the model as input for calibration and validation of the model. After calibration and validation, the model was used to predict the groundwater dynamics in the study area using different recharge scenarios. The validated groundwater model was used to predict the groundwater levels in the study area for the years 2020, 2030 and 2040 with different recharge scenarios. Global climate model was used to generate future weather data. MarkSim developed by the International Centre for Tropical Agriculture (CIAT) was used to generate the weather parameters like maximum and minimum temperatures for the years 2020, 2030 and 2040. The different recharge scenarios with average, lowest and highest recharge over the study period and projected evapotranspiration have been used and revealed that the groundwater levels increase with the increase in recharge and decreases with the decrease in recharge. The results revealed that the groundwater depleted area would decrease with the highest recharge scenario and it would increase with the lowest recharge scenario in future. The deeper groundwater table would be expected in future at Chimakurthy and Thalluru villages of Prakasam district and Karempudi and Piduguralla villages of Guntur district in the study area. This condition may be due to the excess utilization of groundwater which is less than the groundwater recharge in particular villages. The construction of rainwater harvesting structures for artificial groundwater recharge in those areas should be carried out immediately.

Suitable Site Selections for Artificial Recharge Structure in Bandalli Watershed. Chamaraja Nagar District, Karnataka, India Using Remote Sensing, and GIS Techniques.

Bandalli watershed is characterized as an arid to semi-arid region with little access to water. Water is essential for all life forms for human consumption, agriculture and industry. Artificial groundwater recharge is a process by which the groundwater scrounges is reduced at a rate almighty the augmentation rate beneath natural replenishment conditions. The work aims to understand the groundwater scenario in distinction to the geological point of view as the geology of the area concerned is the primary control of groundwater recharge and potentiality. The study began with gathering and analyzing necessary data for creating water balance and determining the best techniques for artificial recharge. The best artificial recharge sites in the vicinity have been validated. The present investigation is to find and select ideal sites for future zones to create a new shape using GIS (Geographic Information System) software version 10.8. To estimate the appropriateness of the site for artificial recharge, the model incorporated numerous criteria, various parameters slope, Lu/Lc, stream order, soil aspect and hydrology. Artificial recharge planning was calculated using runoff availability, aquifer dimension, priority locations, and local water table conditions. Most areas are undulating to recommend recharge structures, which will help the water table and the agricultural sector to augment the water harvesting to improve the groundwater.

Groundwater Artificial Recharge Potentiality in Al-Qilt Catchment Jericho – West Bank – Palestine

The main research objective is to highlight the potentiality of artificial groundwater recharge in Al-Qilt catchment- Jericho – Palestine regarding the water shortage in the groundwater-supplied areas. Artificial recharge can be a possible option in increasing the storability of the underground aquifer, which will add values to the Palestinian strategy to optimize the total accessibility of groundwater resources. The increase of water demands and the scarcity of water resources in the Jordan Rift areas are putting challenges for the water managers and planners to improve the water supplies in order to reach the best ways for the integrated water resources management. In Al-Qilt catchment, the surface water discharge flowing into the wadies in huge amounts had no noticeable significant benefits. A hydrological model was built for the Qilt basin using HEC-HMS software system and it was considered as an essential tool for better understanding of the basin hydrological situation and its hydrogeological characteristics. The surface runoff water speed was measured to be 3.2 m/s (27<sup>th</sup> of February, 2019) with a cross section width of 9.2 m and 0.75 m hight with water leading to a flow of 18.77 m<sup>3</sup>/s and the total flow of approximately 67565 m<sup>3</sup>/hr. The estimated model simulations reavealed of 18.5 m<sup>3</sup>/s and 66600 m<sup>3</sup>/hr for the speed flow and the total flow respectively and matched with the measured ones. The results were used for improving the aquifer-integrated management in Al-Qilt area and determining of the aquifer potentiality for artificial recharge. The built model results gave guiding to the hydrologists and the decision makers for selecting the appropriate techniques and sites for artificial recharge. The model indicated of good simulation tools to be used for other West Bank catchments.

Assessment and delineation of potential groundwater recharge zones in areas prone to saltwater intrusion hazard: a case from Central Iran

Demarcation of the potential zones for groundwater artificial recharge (GAR) based on the most influential factors is an urgent need for retardation of saltwater intrusion and, thus, sustainability of groundwater resources in the arid zones. This study developed an overlay-index methodology to delineate favorable GAR zones by a linear combination of 11 influential thematic layers in ArcGIS. The proposed methodology was implemented on two coastal aquifer settings Sharif-Abad (SAA) and Qom-Kahak (QKA) aquifers adjacent to Salt Lake, Central Iran. Results indicated that 16.41% of the surface of SAA and 28.58% of QKA were identified as the high potential zone for GAR mainly located in low GW vulnerability parts. Based on the analysis of the area under the receptive operating curve (AUC), the produced GAR map has an accuracy of 0.643, and 0.611 for SAA and QKA aquifers, respectively, which relies on the acceptable limit. Finally, the quantity of water required for GAR to control the intrusion of seawater at the suitable parts of these aquifers was estimated as 25 MCM and 35 MCM, annually. The methodology adopted in this study can serve as a holistic assessment for the detection of SWI in coastal aquifers, and also a comprehensive blueprint for managers to delineate the favorable GAR zones, especially in arid regions.

Application of GIS Techniques in Identifying Artificial Groundwater Recharging Zones in Arid Regions: A Case Study in Tissamaharama, Sri Lanka

Groundwater resources are severely threatened not only in terms of their quality but also their quantity. The availability of groundwater in arid regions is highly important as it caters to domestic needs, irrigation, and industrial purposes in those areas. With the increasing population and human needs, artificial recharging of groundwater has become an important topic because of rainfall scarcity, high evaporation, and shortage of surface water resources in arid regions. However, this has been given the minimum attention in the context of Sri Lanka. Therefore, the current research was carried out to demarcate suitable sites for the artificial recharging of aquifers with the help of geographic information system (GIS) techniques, in one of the water-scarce regions in Sri Lanka. Tissamaharama District Secretariat Division (DSD) is located in Hambanthota district. This region faces periodic water stress with a low-intensity seasonal rainfall pattern and a lack of surface water sources. Hydrological, geological, and geomorphological parameters such as rainfall, soil type, slope, drainage density, and land use patterns were considered to be the most influential parameters in determining the artificial recharging potential in the study area. The GIS tools were used to carry out a weighted overlay analysis to integrate the effects of each parameter into the potential for artificial groundwater recharge. The result of the study shows that 14.60% of the area in the Tissamaharama DSD has a very good potential for artificial groundwater recharge, while 41.32% has a good potential and 39.03% and 5.05% have poor and very poor potential for artificial groundwater recharge, respectively. The southern part of the DSD and the Yala nature reserve areas are observed to have a higher potential for artificial groundwater recharge than the other areas of Tissamaharama DSD. It is recommended to test the efficiency and effects of groundwater recharge using groundwater models by simulating the effects of groundwater recharge in future studies. Therefore, the results of the current research will be helpful in effectively managing the groundwater resources in the study area.

Prediction and quantification of bioclogging depth limit and rate based on numerical simulation and experimental validation in managed aquifer recharge

AbstractMany microorganisms are naturally occurring in both recharging water and porous media, and microorganisms will grow and clog the pores of porous media. Porous media show different clogging depth and rate, which depends on the carbon source concentration. The bioclogging depth limit and rate under the effect of the nutrient concentration can be disentangled through column experiments and numerical simulation approaches. We use the TOUGHREACT method‐based on the monod equation of microbial growth to explore the process of microbial growth and permeability change, and correct with experimental results. The experimental results show the influence of nutrient concentration (glucose) on microbial growth and clogging of porous medium, and leads to clogging of porous medium. The clogging rate was defined as the rate of change of hydraulic conductivity with time for quantitative study of bioclogging in our study. Simulated results found that the clogging rate increases 0.035 and 0.00673 (m/d/min) respectively in the glucose concentration range of 0.045–0.6 and 0.6–5 mmol/L, simultaneously, the ultimate clogging depth decreases 18.2 and 1.7 mm respectively in the glucose concentration range of 0.045–0.6 and 0.6–5 mmol/L. The aim of this study was to evaluate the effects of nutrient concentrations on bioclogging and shed light on the establishment of nutrient concentration standards for recharge water during groundwater artificial recharge.

Reviving traditional rain-water harvesting system and artificial groundwater recharge

Reviving traditional rain-water harvesting system and artificial groundwater recharge

Field Experimental Study on the Infiltration and Clogging Processes at Aksu Research Site, Kazakhstan

The challenge of a good quality drinking water supply to southeastern Kazakhstan’s local population from far-away natural surface water sources motivates groundwater utilization from local aquifers. To prevent groundwater resource deficits, artificial groundwater recharge is needed. To this end, infiltration and clogging processes were evaluated through comprehensive field research in southeastern Kazakhstan’s typical river drainage basin (Aksu experimental site). The infiltration scenario included constructed mini pools and their typical soil profile clogging and silting processes. The local aquifer unsaturated and upper saturated zones underwent a detailed study of water balance, hydrodynamic setting, and filtration properties. The research results suggest that the infiltration rate decreased from 15 m/day until the saturation steady state and remained at 0.75 m/day until the end of the experiment. In summer, clogging layers with thicknesses ranging from 3 mm for the clayey silt layer to 6 mm for muddy clay began to form at the mini pools nearly one month after the test began. During infiltration, the mini pools’ upper soil layer dirt-holding capacity varied from 3.72 to 5.25 kg/m2. The field study results serve as a factual basis for artificial replenishment system design and groundwater replenishment methodology optimization in southeastern Kazakhstan and similar regions.

Identification of potential artificial groundwater recharge sites in an alluvial setting: A coupled electrical resistivity tomography and sediment characterization study

Alluvial aquifers are one of the most exploited and easily accessible aquifer networks across the world, as they coincide with regions of intensive human settlements. Over the years, improper management and overexploitation of groundwater has severely stressed the natural replenishing capacity of these aquifer systems. Identification of potential artificial recharge networks and their monitoring are urgently needed for long-term sustainable groundwater management. In this study, an efficient and cost-effective strategy to locate prospective groundwater recharge zones is devised by integrating electrical resistivity tomography (ERT), sediment characterization, and temporal monitoring techniques. The efficacy of the above strategy is evaluated in the central part of Indo-Gangetic basin (IGB). Correlation of 2-D ERT models with borehole lithology and depth-wise variation of hydraulic parameters deciphered the existence of prospective regions composed of highly permeable strata within ∼6–48 m depth. In addition, the behavior of the delineated prospective regions was monitored by applying time-lapse ERT study. The comparison of time-lapse 2-D ERT models highlighted a significant reduction in post-monsoon resistivity profiles, suggesting an increase in saturation levels due to infiltration of rainwater. This study provides an integrated cost-effective approach for identification of prospective artificial recharge sites and monitoring their efficacy in replenishing shallow aquifers, thereby enabling sustainable groundwater management.