Evaluation of Vulnerability Zone of a Coastal Aquifer Through GALDIT GIS Index Techniques

摘要: Abstract Seawater incursion (SWI) is an universal threat magnified by rising sea levels, climate change, and escalating dependence of coastal fresh groundwater resources for the water supplies needed. Therefore SWI intrinsically very difficult more expensive to examine, investigate, project. Taking into account abovementioned issues current study was carried out in Nagapattinam region, Tamil Nadu, Southern India. The modern technique (GALDIT) adopted this identification region. Groundwater samplings were at 30 locations six hydrologeological parameters used obtain information on areas. results were: occurrence (G) unconfined, aquifer hydraulic conductivity (A) ranked as 5–7.5, depth above level (L) between 2.5 7.5, parameter distance from (D) showed ranking 7.5–10, impact existing conditions seawater intrusion area (I) given index thickness (T) varied 10. From calculated GALDIT > 7.5; it that high vulnerability areas identified 23 30. remaining seven classified moderate vulnerability. final output indicates major portions are highly affected seawater.