Groundwater Potential Zonation of Unchehra Watershed, Central India using AHP, Remote Sensing, and GIS Techniques

Abstract

Groundwater is the primary source of domestic and agricultural water in the semi-arid regions of central India. Despite receiving moderate annual rainfall, Unchehra watershed experiences seasonal water shortages, especially during summer, highlighting the need for scientific assessment of groundwater resources. This study delineates groundwater potential zones (GWPZs) in the Unchehra watershed using an integrated Remote Sensing (RS), Geographic Information System (GIS), and Analytical Hierarchy Process (AHP) approach. Seven major factors influencing groundwater occurrence lineament density, geology, land use and land cover (LULC), drainage density, geomorphology, slope and soil type were considered in the analysis. Spatial thematic layers for these parameters were prepared from satellite imagery and Digital Elevation Model (DEM) data using ArcGIS. The relative importance of each factor and its classes was determined through AHP, providing a systematic weighting scheme for groundwater potential assessment. The weighted layers were integrated to generate a groundwater potential zonation map. The resulting map classified the watershed into five groundwater potential zones: very low, low, moderate, high, and very high. The analysis revealed that 7.88% of the watershed falls under very low potential, while significant portions of the area exhibit moderate (28.07%) to very high (22.61%) groundwater potential. To assess the reliability of the generated model, validation was carried out using 41 randomly selected dug wells and Receiver Operating Characteristic (ROC) curve analysis. The near-zero Consistency Ratio (CR) confirms the reliability of the AHP weighting scheme, while the Area Under the Curve (AUC) value of 0.763 indicates good predictive accuracy of the groundwater potential model. The identified high and very high groundwater potential zones are suitable for groundwater development and artificial recharge measures such as check dams, percolation tanks, and recharge wells. The integrated RS-GIS-AHP framework developed in this study provides a reliable decision-support tool for groundwater exploration, recharge planning, and sustainable groundwater management in Unchehra watershed and similar hydrogeological settings.