Evaluation of the groundwater quality along coastal stretch between Vembar and Taruvaikulam, Tamil Nadu, India: a statistical approach

Abstract

The present study investigates the groundwater quality from Vembar to Taruvaikulam coastal area to provide an overview of the relationship and sources of physicochemical parameters. A total of 23 groundwater samples were collected and analyzed for various physico-chemical parameters such as pH, electrical conductivity (EC), total dissolved solids (TDS), calcium (Ca 2+ ), magnesium (Mg 2+ ), sodium (Na + ), potassium (K + ), bicarbonate (HCO 3 2- ) , chloride (Cl -) and sulphate (SO 4 2-). The ionic concentrations confir m most of the groundwater samples belong to order of (Na +) > (Mg 2+ ) > (Ca 2+ ) > (K +) and (Cl -) > (SO 4 2-) > (HCO 3 2-). Spearman's correlation matrix, principal component analysis (PCA) was used to distinguish the main contamination sources in the study area. The significant correlation (r=>0.5) of EC, TDS, sodium, magnesium and chloride indicates saline intrusion, insignificant correlation ( r=<0.5) on calcium and bicarbonate ions attribute to a fresh water source. Four varimax components were extracted from PCA, which explained 55.3, 19.20, and 0.98% of the variation in the groundwater quality in present study area. The components obtained from PCA indicated that seawater intrusion, industrial pollution, geological activities and anthropogenic activities exists in the study area.