Assessment of Groundwater Quality by Integration of Water Quality Index and GIS Techniques

摘要

Pavagada taluk in Tumkur district is one among the drought prone region of the state where shortage of rainfall has severely reduced groundwater level in various bore wells of Pavagada taluk and which further leads to geogenic contamination of groundwater and hence degrades the groundwater quality. Fourty nine groundwater samples were collected and assessed where maximum population is dependent on groundwater. The chemical analysis was carried out for Alkalinity, pH, Electrical Conductivity, TDS, Calcium, Iron, Sulphate, Magnesium, Nitrate, Fluoride and Chloride are analyzed and compared with BIS 10500:2012. pH value from the collected groundwater samples ranges from 6.63 to 9.65 which is slightly acidic to basic and total hardness is categorized from moderately hard to very hard its values vary 78 mg/1 and 444 mg/1. Iso-contour maps were prepared to recognize spatial distribution of various contaminants within the study area and to identify the suitability of drinking water quality in Pavagada taluk Water Quality Index (WQI) is used. The WQI value ranges from 12.54 to 174.11, Fluoride and Nitrate concentration was above permissible limit in few sampling sites has influenced the higher WQI values. More than 90% of the groundwater samples is in "excellent" & "good category" and remaining 10% of the samples are within "fair" and "unfit for drinking" category these values suggest that the parameters like fluoride have affected the WQI, thus water can be utilized after proper filtration.