Assessment of vulnerability in the aquifers of rapidly growing sub-urban: a case study with special reference to land use

Abstract

Groundwater vulnerability was assessed through the SINTACS-LU model to explore the aquifers which are more susceptible to contamination. The aquifers of the Palayamkottai taluk are at risk due to the uncontrolled agricultural practice and urbanization. As these aquifers are the source of water to most of the population, mitigation of the risk to the aquifer is essential. This proposed model uses eight parameters like water table depth, effective recharge, depth to unsaturated zone, soil media, aquifer media, hydraulic conductivity, topography, and land use to assess the vulnerability through index measurements. The index in the vulnerability map was reclassified through the cumulative score index (CSI) technique. Sensitivity investigation was done to survey the effect of each parameter over the vulnerability. Agricultural regions (185 km2) and built-up regions (50 km2) covering more than 50% of the land use exert pressure on the intrinsic resistance of the aquifers and put them at risk. The classified map has four classes according to vulnerability such as very high vulnerable zone (53.3 km2), high vulnerable zone (81.95 km2), moderate vulnerable zone (125.22 km2), and low vulnerable zone (39.8 km2). The vulnerability assessment made by the inclusion of land use in the intrinsic vulnerability can help in sustainable development of sub-urban regions.