Identification of groundwater potential zones and its relation to settlement and agriculture: a study in Taraphini river basin, West Bengal, India

Water shortage has become a crucial problem in many regions of the world. The study has been conducted on the Taraphini river basin, situated at the plateau fringe in the western part of West Bengal, India. This is a hard rock region under a dry tropical sub-humid climate facing intense water shortages during dry seasons, increasing pressure on groundwater. Thus, the occurrence of groundwater becomes a concern. The groundwater potential regions are identified by applying the Analytical Hierarchy Process (AHP) and Multi-Influencing Factor (MIF) methods with an integrated Remote Sensing and Geographical Information System approach. Eight influencing factors- Geomorphology, Lineament density, Hydrogeology, Rainfall, Drainage density, Land use land cover, Slope and Soil types were analysed and assigned scores and weights according to their influence on groundwater and prepared two maps by integrating these factors in GIS system. The resultant groundwater potential maps are validated using groundwater level data of 50 groundwater wells in the region and the accuracy of the models is assessed through Receiver Operating Characteristics (ROC). The maps were divided into five classes. More than 55% of the area has very low and low groundwater potentiality, where, settlement is compact and developed in small patches and they practice rain-fed agriculture. Whereas, only 7% and 11% area of the region has very good and good groundwater potentiality, where, agriculture is irrigation-based and bigger and more compact settlements developed. The results of the study will benefit sustainable groundwater resource management in the hard rock region of the study area.