Application of geospatial technology for delineating groundwater potential zones in the Gandheswari watershed, West Bengal

Abstract

Identification of groundwater potential zones needs an understanding of different hydro-geological parameters of the concerned region. This present study done on Gandheswari watershed of West Bengal is mainly based on RS and GS techniques. Seven important parameters are taken into consideration namely geology, lineament, slope, drainage, soil, rainfall, and land use and land cover which are mutually interdependent to each other in the groundwater development process. Satellite image of Landsat-8, SRTM-DEM of USGS, rainfall data of IMD, topographical sheets of SOI, geological map of GSI, soil map of NBSS&LUP are collected and processed as per requirements in the ArcGIS, Erdas Imagine and PCI Geometica software to create or extract layers for all the parameters. The MIF technique is applied to assign weight to each parameter based on its level of influence to other parameters. All the layers are now integrated together adopting weighted overlay method in ArcGIS software. The prepared final map shows the groundwater potential zones of the Gandheswari watershed. An accuracy assessment is done based on groundwater fluctuation data of last 10 years (2018–2009) from CGWB calculating Kappa co-efficient to validate the study. The study reveals that an area of 275.9 km2 (69.86%) is found to be good prospect of groundwater. The overall accuracy level of the study is calculated to be 84.62%, while the result of the Kappa co-efficient is 88% for the same.