Assessment of basin-scale groundwater potentiality mapping in drought-prone upper Dwarakeshwar River basin, West Bengal, India, using GIS-based AHP techniques

Sustainable use of groundwater is essential in any region to increase long-term agricultural sustainability as well as to maintain the pace of socio-economic development of the region. Groundwater is a most vital and valuable natural resource for ecosystems and communities in the drought-prone western part of West Bengal, India. The intensity of agriculture in drought-prone areas has resulted in the expansion of groundwater. The current study has been conducted in a semi-arid upper Dwarakeshwar River basin which is basically a meteorological as well as agricultural drought-prone and agro-economy-based region. The current paper attempts to illustrate the areas of groundwater potentiality by using Analytical Hierarchy Process (AHP) and Geographic Information System (GIS). Appropriate weight has been determined for each factor and their subclasses on the basis of their relative importance by using the AHP technique. The final output map has been integrated by using total twelve sets of groundwater influencing thematic layers, namely: aquifer media, mean annual groundwater level, lithology, land use and land cover, rainfall, drainage density, soil drainage, soil texture, Normalized Difference Vegetation Index (NDVI), elevation, curvature, and slope. It has been classified into five zones: very poor, poor, moderate, well, and excellent covering an area of 256.87 km2 (13.38%), 581.79 km2 (30.30%), 607.91 km2 (31.66%), 381.58 km2 (19.87%), and 91.36 km2 (4.76%), respectively, and finally, results have been validated with the help of mean annual groundwater level data of 50 dug wells through the Receiver Operating Characteristic (ROC) curve. The result of Area Under Curve (AUC) value is 0.871 that indicates 87.1% accuracy and reliability for better planning, management, and resource development in an effective way.