Delineation of groundwater potential zones using AHP and GIS techniques: a case study in Barakar river basin, India

The present study attempts to delineate and map the groundwater potential zones (GWPZ) of the Barakar river basin in Jharkhand, through the integration of satellite images and geospatial techniques, using an analytical hierarchical process (AHP). Thematic layers of ten influential factors namely geomorphology, slope, curvature, drainage density, lineament density, geology, land use/land cover, rainfall, soil, and topographic wetness index are prepared and used for groundwater potentiality mapping. The analytical hierarchical process (AHP) method is adopted to assign weight to each of the ten criteria and their sub-criteria according to their role as an influential factor of groundwater recharge. The final groundwater potential map is produced by combining all ten thematic layers, using the weighted overlay analysis technique and spatial analysis tool in ArcGIS. The result shows that very poor, poor, moderate, good, and excellent groundwater potential zones covering an area of 284.95 km 2 (4.42%), 1709.93km 2 (26.56%), 1906.01 km 2 (29.6%), 1244.20 km 2 (19.32%), and 1292.52 km 2 (20.07%) respectively. Good to excellent groundwater potential zone occupied an area of about 2536.72 km 2 with flat topography and well-drained sandy soil characteristics in the downstream areas of the basin. South and western parts of the area presented poor to very poor groundwater prospect covering about 1994.88 km 2 area with hard rock formation, steepest slope, and high altitude and drainage density. The obtained result is validated by considering the seasonal fluctuation of groundwater data where the value of R 2 (0.70) and RMSE (7.633) indicated that obtained result is reliable and may help to a planner for sustainable management of groundwater resources.