Seasonal variation in ground water quality and its suitability for drinking and agriculture –a case study in Kancheepuram region, Tamil Nadu, India

In the present study an attempt has been made to assess the seasonal ground water quality variations at Kancheepuram region, Tamil Nadu, India. In order to evaluate the seasonal ground water quality for drinking and irrigation purposes, 68 groundwater well data were collected and analyzed for various physico-chemical parameters such as electrical conductivity (EC), pH, total dissolved solids (TDS), total hardness (TH), Na⁺, Ca²⁺, Mg²⁺, Cl^-, SO₄^2-, HCO₃^- and F^-. Nine parameters viz., pH, TDS, TH, Ca²⁺, Mg²⁺, Cl^-, SO₄^2- , HCO₃^- and F^- were used to calculate the Water Quality Index (WQI) using weighted arithmetic index for drinking purpose. EC and Sodium Adsorption Ratio (SAR) were the two important indicators used to assess the irrigation water quality. Mapping was done to examine the spatial distribution of water quality parameters using Geographical Information System (GIS). From the analysis, more than half of the samples record good water quality whereas only 1% falls under unsuitable category for drinking purpose. Approximately 33% of samples falls under poor quality for drinking. In terms of irrigation, the salinity hazard occurs in 23 to 42% of sampling locations depicting the uncertainty towards agricultural production in the study region. From the study, it is observed that the water quality is highly degraded where Industrialization and urbanization took place when compared to areas where agriculture is being practiced. Hence, suitable measures to ameliorate the pollution effect of urbanization and industrializations are suggested.