8. Groundwater Vulnerability Assessment Using Drastic Method: A Case Study of Bhilwara District, Rajasthan

Globally, groundwater (GW) is a significant source of fresh water utilized in home, commercial, industrial, and other applications, as well as in ecosystem support. As a result, Rajasthan, a desert state in India, has experienced groundwater quality issues caused by both man-made contaminants and naturally occurring hazardous minerals. With a land size of 10,445.1 square kilometers, the Bhilwara district is situated in southern Rajasthan. Since groundwater contamination will directly influence human health, it is important to evaluate how it is affected by the availability of minerals, the rise in anthropogenic activities, and the number of mining companies. The DRASTIC model, based on a geographic information system (GIS), was used in this study to create a susceptibility vulnerability map of the groundwater system. Adding Land Use (LU) maps from the research area has further upgraded the DRASTIC maps. Using a technique called hotspot mapping, it is possible to forecast how many significant hotspots will be present in the area under study and to find the sources of contamination. The water quality index and overlay approach were also used to understand the state of vulnerability better. The results showed that the index value has seven subclasses and spans from 100 to 205. The DRASTIC and DRASTIC–LU maps were linked with the nitrate concentration map for validation. It was discovered that the Sahara, Mandal, and Raipur blocks are particularly susceptible to the rapid increase in nitrate concentration. The highest percentages of TA, TDS, and NO₃₋ (100%) are found in the entire dataset.