Groundwater Quality Analysis in Precambrian Rocks of Chitradurga District, Karnataka, India Using Geo-informatics Technique

Abstract

Water is the main source for domestic, engineering, industrial, agricultural and multipurpose uses which affects surface as well as groundwater quantity. The study area falls within the semiarid region and frequently facing water scarcity and quality problems. The present study generates the primary data to map the spatial variation of groundwater quality in Precambrian hard rock terrain of Chitradurga District through Geo-informatics technique. Efforts have been made to evaluate a total number of 50 representative groundwater samples (C1 to C50) collected in well points from different parts of the study area during pre-monsoon period (April-2012) to assess its parameters such as Fluoride (F-), Nitrate (NO3−), Carbonate (CO3-), Chloride (Cl-), Calcium (Ca2+), Magnesium (Mg2+), Sodium (Na+), Sulphate (SO42−), Iron (Fe), Potassium (K+), Total Dissolved Solids (TDS), Potential of Hydrogen (pH) and Total Hardness (TH). Groundwater quality is found to be more controlled by rock-water interaction & residence time of water in aquifers and affected by both anthropogenic and geogenic factors at many locations. Each lithological units, water bodies, agricultural lands and major lineaments are mapped and digitized using IRS-1D, PAN+LISS-III satellite data through GIS software's to evaluate the possible contamination of groundwater quality by rock-water interactions, agro-chemicals and storage & movement of water. This study highlights the potentiality of Geo-informatics technique in preparation of more consistent and accurate baseline information predicting the groundwater quality in Precambrian hard rock terrain of the study area; which is a suitable model in similar geological conditions.