Isotopic differentiation of groundwater recharge processes in a semi-arid region of southern India

Ensuring the availability of adequate quantity and quality of water to meet demands of domestic sector has become the prime objective for the developing countries like India. The coastal and the nearby inland region are the places of intense human activity due to urbanisation and industrialization leading to the depletion and degradation of environmental resources. The present investigation on the coastal and inland aquifers of Tuticorin, Gulf of Mannar, Tamil Nadu aims to better understand the recharge characteristics, factors controlling recharge, effect of weather parameters on recharge, source of recharge water, differences between inland and coastal recharge processes and climatic signature in groundwater isotopic composition from the hydrochemical and stable isotope data. Different mechanisms of salinization in the coastal aquifers were deduced as direct influence of the sea water and concentrations of ions by evaporation. The dissolution or leaching from the aquifer material is also imparting salinity to groundwater in this area.