A GIS-based evaluation of hydrochemical characterisation of groundwater in hard rock region, South Tamil Nadu, India

Groundwater is a major source for domestic and agricultural uses in Natham Taluk, Dindigul district, Tamil Nadu, India. The intention of this study is to determine the quality of groundwater for domestic and irrigation purposes in the hard rock region. Totally, 37 samples were collected and analysed for physical parameters that are pH, EC, TDS, TH, major cations and anions. Piper diagram shows that Ca-HCO3 and mixed Ca-Mg-Cl is the most prominent type of water. Gibbs diagram reveals that the higher concentrations of magnesium, sodium and potassium ions are accredited to geological sources such as rock-water interaction, ion exchange process and evaporation that are the major factors affecting the nature of groundwater. In view of irrigation indices, most of the sample locations are fit for irrigation use except magnesium hazard value. Additional statistical analysis, such as correlation and principal component analysis, was calculated using SPSS software. All results are indicated; weathering, rock-water interactions and anthropogenic activities are a significant factor that alters the existence of groundwater in the research area.