Hydrogeochemical Survey along the Northern Coastal Region of Ramanathapuram District, Tamilnadu, India

Ramanathapuram is a drought-prone southern Indian district that was selected for conducting hydrogeochemical study. Groundwater samples from 40 locations were collected during January 2020 (pandemic interdiction according to COVID) and 2021. The properties of the groundwater evaluated compared with drinking water regulations assess their quality. order cation dominance as follows: Na+ > Ca2+ K+ Mg2+ in 2021 respect mean value. anion Cl− HCO3− SO42− NO3− F− In study area, coastal region identified groundwater-polluted zone through spatial analysis based on all results. irrigation quality analyzed using various calculated indices, such Na% (percent sodium), SAR (sodium absorption ratio), PI (permeability index), MgC (magnesium risk), RSC (residual sodium concentration), KI (Kelly demonstrating suitability most parts area. This also confirmed by vs. EC Plot, USSL, Doneen’s Plot PI. addition, WQI results except regions. dominant hydrogeologic facies Na+-Cl−, Ca2+-Mg2+-SO42−, Ca2+-Mg2+-Cl− types illustrated Piper diagram indicate mixing process freshwater saline aquifers. Rock–water interaction evaporation main controllers geochemistry determined Gibbs plot. Ion exchange, seawater intrusion, weathering carbonates, dissolution calcium gypsum minerals aquifer major geogenic processes controlling chemistry Chadha plot, scatter Cl−/HCO3− ratio. Further, multivariate statistical approaches strong mutual relationship among parameters, several factors hydrogeochemistry, grouping parameters. Appropriate artificial recharge techniques must be used affected regions stop intrusion increase recharge.