A GIS based DRASTIC model for assessing groundwater vulnerability in Jangalmahal area, West Bengal, India

Groundwater vulnerability assessment to delineate areas that are more susceptible to contamination from anthropogenic source has become an important element for sensible natural resource management and land use and land cover planning of Jangalmahal area. This contribution aims at estimating aquifer vulnerability by applying the DRASTIC model in Jangalmahal (some parts of Purulia, Bankura, and West Medinipur) area. The maps of aquifer vulnerability to pollution are becoming more in demand because on the one hand groundwater represents the main source of drinking water, and on the other hand high concentrations of human/economic activities, e.g. industrial, agricultural, and household represent real or potential sources of groundwater contamination. There is a need to conduct studies on groundwater pollution. The signature of water resource and the potential for groundwater quality to decline due to various anthropogenic activities within the Jangalmahal area has necessitated this study using a combination of DRASTIC and GIS method. The DRASTIC models have considered seven parameters viz. depth to water level, net recharge, aquifer material, soil material, topography, impact of vadose zone and hydraulic conductivity. The study area reveals that about 43.5% of the watershed area is exposed to high-risk, 11.6% exposed to medium-risk, and 45.26% exposed to the watershed are dominated by high vulnerability classes while the north western and middle portions are characterized by moderate vulnerability classes. The study northern and lower part is minor aquifer vulnerability zone are categorised. Finally, it is realized that GIS is an effective platform for groundwater vulnerability mapping with consistent accuracy assessment, and therefore, the present study is more suitable for geo-environmental planning and analytical of groundwater management.