Groundwater Vulnerability Assessment in Pavagada taluk, Tumakuru district, Karnataka, India, using a GIS-based DRASTIC model

Abstract

Throughout the world, one of the most accessible resources is groundwater. Groundwater quality is rapidly declining due to anthropogenic and geogenic sources, resulting from over-reliance. Previous research indicates that the concentration of pollutants such as Fluoride, Arsenic, Iron, and Total Dissolved Solids has rapidly increased. This affects crop yield and human health as well as the socioeconomic development of the region. For this reason, identifying areas where groundwater is vulnerable is crucial to reducing pollution in groundwater and maintaining its quality. In this study, groundwater-vulnerable zones in Pavagada Taluk are evaluated using the GIS-based DRASTIC model. The seven DRASTIC parameters are combined with data on land use and land cover to help explain how anthropogenic sources and possible human intervention affect groundwater quality. It is observed that the groundwater samples we collected had high concentrations of Iron, Sulphate, Fluoride, and Nitrate, as per BIS 10500 (2012). The study area's northeastern, southeastern, northern, southern, and southwestern regions are classified as high to moderate risk zones on the final DRASTIC map. The high Fluoride content in groundwater is caused by bore wells situated on rocks such as Granite, Granodiorite, Hornblende-Biotite Gneiss, and Biotite. In order to validate the model, the results of the physicochemical analysis were compared to the final drastic map. This comparison shows that the model is 80.39% valid for the region.