Assessing the potential of hard rock terrain to store groundwater using AHP techniques in the Vedavathi River Basin, India

Abstract

In recent years, human activities and uneven development have significantly reduced groundwater recharge, which is a crucial resource. Understanding the potential for groundwater is essential for managing and extending research areas. Designing and implementing structures to correct groundwater replenishment requires this knowledge. The Vedavathi River basin shows that groundwater availability varies over time and geography, necessitating a comprehensive assessment. Using a weighted overlay method, the Vedavathi River basin has been categorized into Groundwater Potential Zone (GWPZ): extremely high (1849.912 km²), high (7320.034 km²), moderate (9038.448 km²), low (4804.256 km²), and very low (283.6686 km²). The graphic illustrates that the basin's midland has significant groundwater potential, with substantial groundwater zones found in areas of heavy rainfall and significant infiltration. Our study's GWPZ were cross-validated using data from the Central Groundwater Board (CGWB) observation wells. The map's accuracy was confirmed by matching it with well-yield data. The model's performance was assessed using the Receiver-operation characteristics (ROC) curve, revealing that the Analytical Hierarchy Process (AHP)-based map achieved an 89% accuracy. This result aligns well with the predicted potential zones and well-yield data. The application of GIS and AHP methods to delineate GWPZ is relevant for river basin planning and development in tropical and subtropical regions with varied geological environments.