Delineation of groundwater potential zone using analytical hierarchy process and GIS for Gundihalla watershed, Karnataka, India

Remote sensing (RS) and geographical information system (GIS) have a wide range of applications in groundwater assessment, exploration, and resource management. Several other types of research targeting the water quality assessment in the study area have been done. However, the present work is the first attempt to delineate the groundwater potential zone using a different approach. This paper finds the way to identify the groundwater potential zone for Gundihalla watershed located in the hard rock region of Bellary district in Karnataka state. Various thematic layers such as geomorphology, lithology, land use and land cover (LULC), soil, drainage density, lineament density, rainfall, and slope were prepared for the study area. The various sub-criteria of each thematic layer were ranked based on their influence in the groundwater recharge, and each thematic layer was given a weightage, derived from the analytical hierarchy process (AHP). The overall groundwater potential map for the study areas is obtained by performing a weighted overlay analysis of all the thematic layers. The resultant groundwater potential zone (GWPZ) map is further categorized into five different groundwater potential: very good (76%) good (23.70%), moderate (23.30%), poor (18%), and very poor (16.40%). The obtained results were validated using groundwater fluctuation data for pre- and post-monsoon periods. The validation holds well for the methodology adopted. Thus, the results were utilized for carrying out water management through artificial recharge and further exploration approaches.