Integrated Geospatial Analysis for Groundwater Potential Zone Mapping in Semi-arid Rainfed Areas of Yadgir District, Karnataka, India

Abstract

Background: Groundwater is a crucial freshwater resource in semi-arid regions where surface water availability is limited and highly seasonal. Aim: This study presents an integrated geospatial approach for delineating groundwater potential zones (GWPZ) at the village level, extending prior district-scale mapping of the region by incorporating higher-resolution data and borewell-derived hydrogeological evidence. Study Design: The study was conducted during 2025-26 using a multi-criteria decision analysis (MCDA) technique based on the Analytical Hierarchy Process (AHP) in 45 villages spread across Yadgir and Gurmitkal blocks of Yadgir District, Karnataka, India. Methodology: A comprehensive geodatabase was created incorporating satellite data including ALOS PALSAR DEM (12.5 m), IRS ResourceSAT-2 LISS-IV imagery (5.8 m), and borewell hydrogeological data documented from 247 borewells across the 45 villages. Thirteen thematic layers were integrated through AHP-based weighted overlay analysis in a GIS environment, weighted in order of influence as geomorphology (20.1%), rainfall distribution at 50% dependability (15.7%), static water level (13.1%), slope (10.4%), soil classification (7.4%), second water strike (7.3%), geology (5.9%), first water strike (4.9%), lineament density (4.8%), land use/land cover (3.5%), water bodies density (2.6%), drainage density (2.2%), and landforms (2.1%). The study extends earlier five-parameter, coarser-resolution regional mapping of the district by adding three borewell-derived layers alongside the conventional remote sensing themes. Results: The analysis classified the study area into five groundwater potential categories: highly potential (23,146 Ha), potential (1,25,487 Ha), medium potential (23,305 Ha), less potential (1,102 Ha), and very low potential (4,294 Ha), together forming 1,77,334 Ha. Approximately 83.8% of this classified area (1,48,633 Ha) falls under the combined highly potential and potential categories. This classification covers the wider Yadgir and Gurmitkal blocks; the 45 target villages span 58,768 Ha (587.7 sq km) per cadastral records. Water balance analysis estimated 496 MCM of total potential water, with 112 MCM as surface runoff, of which only about 27 MCM (~24%) is currently harvested, leaving most villages seasonally water deficient. Conclusion: Approximately 83.8% of the classified area possesses high to moderate groundwater potential, indicating that the region is not geologically water-constrained and that the local water deficit stems from inadequate capture and storage rather than a lack of exploitable groundwater. The resulting GWPZ map provides a village-level scientific basis for prioritizing new borewell siting, groundwater recharge and water-harvesting structures.