Application of Water Quality Index and Multivariate Statistical Analysis in the Hydrogeochemical Assessment of Shallow Groundwater in Part of Purna Basin, Maharashtra, India

In the present study, descriptive statistics, multivariate statistical technique and geochemical technique was applied to assess the major factors controlling the hydro-geochemistry of the GP-2 watershed, part of Purna basin, Aurangabad, Maharashtra, India. Twenty-one (21) groundwater samples were collected covering entire part of watershed. Groundwater samples were tested for their physico-chemical parameters such as pH, electrical Conductivity (EC), total dissolved solids (TDS), total hardness (TH), calcium (Ca⁺⁺), magnesium (Mg⁺⁺), sodium (Na⁺), potassium,(K⁺) chlorides (Cl^-), sulphate (SO₄^-), carbonate (CO₃^-), bicarbonate (HCO₃^-), nitrate (NO₃^-), and fluoride (F^-). The results were evaluated and compared with WHO (2011) and BIS (2012) water quality standards. The piper trilinear diagram shows that groundwater samples are of mixed CaNaHCO₃ and CaHCO₃ type. According to Gibbs diagram, the predominant samples fall in the rock-water interaction dominance field. Based on the WQI results majority of the samples show their excellent to good category. Hydrogeochemical parameters are further studied using statistical tools such as descriptive, correlation and cluster analyses, and Factor analysis. In summary, it is observed that the hydro-geochemical processes are more dominated in study area and the groundwater chemistry is controlled by geogenic and anthropogenic processes such as cation exchange process at soil water interface, domestic waste, solubility of minerals, and dissolution of lithogenic materials and pollution from application of fertilizers and pesticides to agricultural lands.