DRASTIC model developed with lineament density to map groundwater susceptibility: a case study in part of Coimbatore district, Tamilnadu, India

Groundwater has never been relied on as much as it has been in sections of Coimbatore in the previous two decades due to fast and unplanned urbanisation, industrial, and agricultural expansion. This report seeks to give local and regional planning authorities with a brief groundwater vulnerability assessment of the section of Coimbatore region in order to guarantee more sustainable growth in the area. The part of Coimbatore region, which covers Pollachi, Sulur and Coimbatore south in eastern part of Tamilnadu, is the study’s focal point. The conventional DRASTIC model is used to map the initial groundwater vulnerability assessment. It is then altered by adding “lineament density index” to the original seven DRASTIC features, due to the previously established high correlation between groundwater flow and yield and lineament. The final drastic index map was classed into five categories: very low, low, medium, high, and very high vulnerability, with each covering an area of 840.26, 732.58, 583.46, 183.17, and 167.13 km 2 . The modified drastic index is classified the same five categories, with 965.35, 880.14, 399.21, 158.29, and 103.54 km 2 of land covered in each. Alanthurai, Thodamuthur, Pichanur, and Pollachi are among the most susceptible places in the state. This groundwater vulnerability map will be used to aid in groundwater pollution management and planning.