Spatial assessment of groundwater potential using geospatial techniques and analytical hierarchy process (AHP) in a drought-affected river basin of eastern India

Abstract

Groundwater potential zoning is essential for sustainable water resource management in drought-prone regions. This study aims to delineate groundwater potential zones in the drought-prone Jonk River Basin, part of the Mahanadi River system, where dependence on surface water for domestic, agricultural, and livestock needs necessitates the evaluation of groundwater potential zones as a supplementary resource during periods of water scarcity. To achieve this, multiple groundwater controlling factors, including geomorphology, geology, land use/land cover, rainfall, soil, slope, drainage density, lineament density, and topographic wetness index (TWI), were evaluated. The Analytical Hierarchy Process (AHP) was employed to assign normalized weights and ranks to these factors and their respective classes, while Weighted Overlay Analysis (WOA) within a GIS environment was used to integrate the thematic layers and generate the groundwater potential zonation map. Sensitivity analysis was performed to evaluate the influence of individual factors on the model output. Model validation was carried out using Receiver Operating Characteristic (ROC) curve analysis, in which the predicted groundwater potential classes were compared with observed seasonal groundwater level fluctuation data. The model performance was quantified using the Area Under the Curve (AUC), derived from the true positive and false positive rates. The results indicate that very good and good groundwater potential zones occupy only 0.24% and 2.10% of the basin, respectively, whereas moderate, poor, and very poor zones account for 14.46%, 79.70%, and 3.50% respectively. Sensitivity analysis revealed slope as the most influential factor, while TWI showed the least influence. The ROC-AUC value of 0.95 demonstrates a very high prediction accuracy of the model. The findings highlight the limited availability of high-potential groundwater zones in the basin, and therefore provide a scientific basis for sustainable groundwater management, targeted extraction, and effective planning in water-scarce regions.