Salinization of shallow aquifer in the Karamaniyar river basin, Southern India

Abstract

Groundwater pollution from anthropogenic sources is a serious concern affecting several river basins and coastal aquifer environment. It is very important to acquire the impacts of the enhanced anthropogenic pressure and climatic changes on the evolution of groundwater characteristics in this study. The present study aims to concentrate on the hydrogeochemical characteristics by evaluating the groundwater quality through geographical information system (GIS) and multivariate statistical approach. Fifty groundwater samples were collected from the river basin and analyzed for major physicochemical parameters. The analytical results were interpreted in GIS and multivariate statistical techniques and demarcated the spatial variation of groundwater quality and their site-specific influencing factors over time. The presence of Na–Cl facies reflects the saline nature in groundwater in and around salt pan area. Factor analysis reveals the characteristics of four factors, and it accounted for 88.7% total variability. Significant correlation between TDS with major components of Na+, Mg2+, Cl− ions indicate the presence of saline influence on the groundwater. Cluster I and Cluster II represent fresh to slightly saline in nature, Cluster III mainly indicates the average concentration of EC (8615 µS/cm), chloride (2738 mg/l), and salinity (4.67 mg/l) is mainly due to small-scale industrial effluents, salt pan, agricultural activities, and rock–water interaction with related minerals in evaporite deposits.