Seawater intrusion susceptibility and modeling: a case study of Kerala, India

Many coastal regions around the world are experiencing significant groundwater over-exploitation, necessitating scientific studies to prevent seawater intrusion into coastal aquifers. Accurate assessment of groundwater variation is essential for improved water resources management in these regions. Trend analysis of groundwater levels along the coast of Kerala, India is conducted in this study to identify the most critical areas susceptible to seawater intrusion. The study reveals that Ponnani in Malappuram district, Kerala is particularly susceptible to seawater intrusion. The hydro-chemical characteristics were analyzed to understand the groundwater properties. Groundwater modeling was performed using SEAWAT, which reveals that the Ponnani region is affected by seawater intrusion and the modeled length of intrusion has been found to be 2.5 km during the year 2009. The precipitation data from downscaled GCM was employed to estimate future recharge and the simulated length of intrusion in 2030 under Shared Socioeconomic Pathways 5-8.5 (SSP 5-8.5) has been found to be 1.6 km.