Groundwater potential and recharge zoning in semi-arid Deccan basalt using AHP, infiltration testing and VES

Groundwater targeting in semi-arid basaltic terrains is uncertain because surface indicators of recharge, storage and transmissivity do not necessarily represent the same hydrogeological process. This study develops a field-constrained workflow for delineating groundwater potential zones and recharge-prone zones in the Moha-Karewadi area of the Deccan Traps, Beed district, Maharashtra, India. Seven surface predictors - drainage density, lineament density, slope, land use/land cover, lithology, soil and geomorphology - were prepared in a GIS environment and weighted by the Analytical Hierarchy Process (AHP) to generate the Groundwater Potential Zone (GWPZ) map. A second AHP model incorporated a measured infiltration-rate layer derived from Moha-Karewadi site-level field records to generate the Groundwater Recharge Zone (GWRZ) map; external records from other sites were retained only for data audit and were not used as validation of the final map. Subsurface constraints were provided by eight Schlumberger Vertical Electrical Soundings (VES), interpreted as one-dimensional layered-earth models and assembled into pseudo-sections and geoelectric sections. Very high groundwater potential is spatially restricted, covering about 2.07% of the area, whereas very high recharge suitability covers about 8.86% and occurs mainly where favourable geomorphology, low drainage density, high lineament density and higher infiltration capacity coincide. VES interpretation indicates shallow weathered and fractured basalt near the tanks, commonly within about 7–10 m below ground level, underlain locally by compact basalt that restricts deeper percolation. The main contribution is the separation of groundwater potential and recharge suitability as related but non-equivalent decisions, followed by reconciliation with infiltration and resistivity evidence. The workflow provides a practical screening approach for managed aquifer recharge and groundwater exploration in hard-rock watersheds.