Gis based approach for characterization of groundwater by using water quality index

Groundwater is the source of approximately 33% of the water supplied to households and to the public. It supplies more than 90 percent of the rural population with drinking water. As groundwater is the major source, its quality can be affected by rocks, sediments, industrial discharges, urban activities, agriculture, groundwater pumping, and disposal of waste. The quality of groundwater is therefore considered an extremely severe problem in many cities in developing countries. The objective of this study is to (1) evaluate the spatial distribution of physio-chemical parameters like pH, hardness, chloride, fluoride, sulphate and nitrate, sodium, and potassium; (2) investigate the quality of drinking water by the Water Quality Index (WQI). An intensive field visit was carried out to collect groundwater samples. 8 different bore wells were chosen for determining groundwater quality. Groundwater samples are collected during the pre-monsoon and post-monsoon months of May and November 2017 respectively. The groundwater samples collected from the field were analyzed in the laboratory for different physio-chemical parameters by using standard procedures. The results obtained were compared with the water quality standards specified by IS: 10500-2012. Based on the physio-chemical parameters, the water quality index has been computed for each water sample. The derived water quality index of the study area ranged from 89 to 120 (pre-monsoon) and 62 to 94 (post-monsoon). It is observed that the WQI for pre-monsoon has deteriorated quality compared to post-monsoon. The influence of precipitation to improve water quality by way of dilutions of the chemical components.