Geospatial Analysis of Groundwater Recharge Potential: An Insight into a Hard Rock Terrain of West Bengal, India

This researchGeospatial analysis pertains toGeospatial a thorough analysis of groundwater recharge potential zone mapping in some selected hard rockHard rock terrain of Purulia district, West Bengal, primarily focusing on the Proterozoic-aged Chotanagpur Granite GneissicChotanagpur Granite Gneissic complex and Singbhum group of rocks. The study area receives 1476 mm of rainfall annually. In this context, there is some gap between the natural water supply and the population's rising demand. In light of this situation, effective groundwater resource management becomes crucial to addressing the impending problem of water scarcity. To determine the potential recharge zone of groundwater in such terrain, the Analytical Hierarchy Process (AHPAnalytical Hierarchical Process) in a GISGeographic Information System (GIS) platform is carried out. Altogether, eight thematic layers (viz. geomorphologyGeomorphology, lithology, slopeSlope, lineament densityLineament density, drainage density, soil, landuse, landcover, and rainfall), each representing a distinct aspect related to groundwater recharge, are taken into consideration. Meticulously evaluated thematic layers were integrated using a weighted overlay method in the ArcGISArcGIS 10.8 platform to generate a final composite map based on systematically weighed properties. The modelModels outcome reveals that the entire study area is categorized into five distinct classes, namely very low (126.05%), low (244.93%), medium (465.74%), high (296.20%), and very high (114.57%), based on different levels of potential recharge zone of groundwater. To validate the accuracy and reliability of the model, data from 18 dug wells are used for comparison and verification purposes. The model's suitability in accurately predicting groundwater potential zones is affirmed with a final AUC value of 0.722 (72.2%), determined through ROC curve analysis. Considering the limited water table fluctuation data (6.38–7.91 mbgl) and the aquifer material recharge condition of the study area is moderate to poor. The GRP study found that throughout the entire study region, about 29.22% of the rainwater infiltrates into the ground. These findings provide valuable insight into the region's groundwater resource management and sustainable development. This study successfully employed the AHPAnalytical Hierarchical Process modelModels in conjunction with geospatialGeospatial technology integration to determine the groundwater recharge potential zones in the challenging hard rockHard rock terrain.