Spatial distribution of Groundwater quality assessment using Water Quality Index and GIS techniques in Thanjavur Taluk, Thanjavur District, Tamil Nadu, India

Abstract

Assessment of groundwater quality is of utmost importance to ensure sustainable use of water. Since the availability of water, irrespective of quantity and quality, varies from area to area in Thanjavur taluk. The present paper attempts to determine the spatial distribution of groundwater quality parameters and identify locations with the best quality for drinking and irrigation in the study area using GIS and WQI. Using IDW interpolation methods with ArcGIS 10.8, the spatial distribution maps of physical parameters, anions, cations, WQI, and irrigations indices have been generated. Piper pilot shows that Ca-Mg-Cl (mixed), Na-Cl, Ca-Cl, and Ca–Mg–HCO3 water types are found in the study area. Using a water quality index with a rating scale, 42.85%, 28.57%, and 14.3% of groundwater samples are fit, good, and very poor for drinking purposes, respectively. The obtained results of higher SAR, RSC, Na% show that 75% of groundwater samples are perfectly fit for irrigation purposes due to the long residence time of water, dissolution of minerals from lithological composition, and the addition of chemical fertilizers.  The results of groundwater quality analysis have been used to suggest models for assessing water quality. The present study ascertained that the area's groundwater must be treated prior to consumption and protected from the perils of contamination.