Water quality index and GIS-based technique for assessment of groundwater quality in Wanaparthy watershed, Telangana, India

Abstract

A comprehensive study of 58 groundwater samples was collected in the Wanaparthy catchment area (1600 km2), Telangana, India to assess hydrochemistry, quality, water types, and potability using hydrogeochemical characterization, WQI, and GIS techniques. The main concentrations of Na+, K+, Ca2+, Mg2+, Cl−, F−, NO3 −, and SO4 2− ions in groundwater were analysed using ion chromatography (IC). Physicochemical values of potential hydrogen (pH), total dissolved solids (TDS), and electrical conductivity (EC) were determined using portable Hanna meters, while total hardness (TH), alkalinity, and bicarbonates were estimated by titrimetric methods. The obtained results clarify the main anions and cations, which are found in the order Cl− > HCO3 − > SO4 2− > NO3 − > F− and Na+ > Ca+2 > Mg+2 > K+. Among the various ions measured were fluoride (18.97%), chloride (3.44%), nitrate (8.62%), Sulphate (5.17%), sodium (34.48%), and calcium (1.72 %) found above the acceptable limit values of the authority. Indian Standards (BIS) for drinking purposes. According to Piper's trilinear diagram, two dominant hydrochemical facies were identified, Na-Cl-SO4 and Ca-Na-HCO3 types. The Gibbs diagram conferred the dominance of samples in the area, namely the rock-water reaction and the dominance of evaporation. The WQI shows that 67.79% of the samples refer to excellent to good types of water that are suitable for drinking. The drainage diagram calculated that the concentration of the measured parameters exceeds the lower area, which may be caused by the chemical reaction of the rock-water interaction (infiltration and recharge). Since groundwater is the main source of drinking water in the study area, a proper management plan must be put in place before its quality deteriorates.