GIS-Based Hydrogeomorphic Approach for Identification of Suitable Sites for Artificial Groundwater Recharge Structures in Gaya Ji City of Bihar, India

Abstract

Groundwater is the principal source of domestic, agricultural and industrial water supply in the alluvial tracts of the Gangetic plain. The present study integrates remote sensing and Geographic Information System (GIS) based hydrogeomorphic analysis with field-based verification to identify suitable sites for artificial groundwater recharge structures in Gaya ji City in Gaya District, of Bihar. A Digital Elevation Model (DEM) derived from SRTM data (30 m resolution) was used to generate slope, flow direction, flow accumulation and drainage network layers in ArcGIS, while Survey of India toposheets (1:50,000; sheet nos. 72H1 and 72D13) and Google Earth Pro imagery (~5 m resolution) supported terrain verification through elevation-profile analysis. The integrated interpretation of these thematic layers, combined with the hydrogeological framework reported by the Central Ground Water Board (CGWB, 2022) for Gaya District, revealed that the study area is dominated by gentle slopes (0°-4.4°, locally up to 43.4° on isolated hillocks) and elevations ranging from about 97 m to 238 m above mean sea level, both of which favour infiltration over rapid runoff. Eight candidate locations were identified and evaluated against CGWB (2015) site-selection guidelines, of which recharge trenches were recommended at four sites associated with dispersed sheet-flow and gentle terrain and recharge pits at four sites with moderate, spatially limited runoff. An indicative cost-benefit assessment suggests recharge pits (₹20,000-₹40,000 per structure) and recharge trenches (₹40,000-₹80,000 per structure) are low-cost, low-maintenance interventions with an expected service life of 15-25 years. The study demonstrates that an integrated, low-cost GIS and field-verification workflow can provide a scientifically defensible first-order screening of artificial recharge sites in data-scarce urban settings of the Indo-Gangetic plain.