Debasish Chutia, Satyajit Kataki and Aditya Shankar Kataki
Abstract
Groundwater is a critical component of the hydrological cycle, sustaining ecosystems, baseflows, and human needs. In the Lower-Digaru Drainage Basin, Northeast India, rising groundwater dependence necessitates systematic evaluation of groundwater potential zones (GWPZs) and runoff dynamics. This study applies an integrated geospatial framework, combining Remote Sensing (RS), Geographic Information System (GIS), and Multi-Criteria Decision-Making (MCDM) with the Analytical Hierarchy Process (AHP), to delineate groundwater prospects and assess runoff behaviour. Eight thematic layers, landforms, lithology, lineament density, slope, drainage density, soil drainage, land use/land cover (LULC), and rainfall, were generated, weighted, and integrated. Results reveal that nearly level to gently sloping terrains with agricultural/ vegetated cover exhibit high groundwater potential, whereas steep slopes and urban/barren sectors show poor potential and high runoff risk. The basin-average runoff coefficient (C?0.38) indicates a moderate hydrological response, balancing infiltration and surface flow. The derived groundwater potential map categorizes the basin into very good, good, poor, and very poor zones, with ~45% falling within moderate to high potential classes. Validation using groundwater fluctuation data and Receiver Operating Characteristic (ROC) analysis yielded an AUC of 0.79, confirming predictive accuracy. The findings provide a scientific basis for groundwater exploration, recharge structure placement, and watershed management. The study demonstrates the effectiveness of RS-GIS-MCDM integration in hydrogeological investigations, offering a replicable framework for sustainable water resource management in similar basins under increasing water stress.