Simulation of saltwater intrusion into coastal aquifer of Nagapattinam in the lower cauvery basin using SEAWAT

The groundwater that represents 30.1% of the global freshwater supplies is at risk of being contaminated by saltwater intrusion. Saltwater intrusion is the induced flow of seawater into freshwater aquifers. Saltwater intrusion can occur due to natural processes as well as over-extraction of groundwater from coastal aquifers. Growing urban populations in the coastal regions and thus a higher demand for freshwater, emphasise the importance of proper management of these aquifers and prevention of saltwater intrusion by over-extraction. Numerical modelling is a useful tool in helping hydrologists to understand and predict how saltwater intrusion occurs in coastal aquifers. There are various numerical models that can predict groundwater flow and contaminant transport such as SUTRA, SEAWAT, FEFLOW and MODFLOW. These numerical models are based on the governing equations of groundwater flow and contaminant transport. In this paper, the extension of saltwater intrusion into the coastal aquifers of the Nagapattinam coastal region, Tamil Nadu has been investigated by modelling the region using SEAWAT engine in Visual MODFLOW.