Qualitative Assessment of Groundwater for Drinking Purposes Based on Water Quality Indicators

The purpose of this research is to analyze the quality of groundwater in Khanmirza, Lordegan, Borujen, Ardal, and Kiar cities based on WQI and GWQI indicators based on the Iran Standard and Industrial Research Institute (ISIRI) and World Health Organization (WHO) standard. In this research, 28 samples of groundwater (wells) were collected from different places in Khanmirza, Lordegan, Borujen, Ardal, and Kiar cities from 2020 to 2022 and 10 qualitative parameters HCO3, K, pH, TDS, EC, Ca, Na, Mg, Cl, and SO4 were chemically analyzed in the laboratory. After analyzing the data, the spatial distribution map of the index was prepared for the study area by using the inverse distance weighting interpolation method. The results showed that according to GWQI and WQI indicators, most of the samples were in the good quality category. By examining the Pearson correlation between WQI and GWQI indices and the parameters used, it was found that the two parameters TDS and EC with coefficients of 0.982 and 0.989 have the highest correlation at a significant level of 1% with the WQI index. Also, TDS and Ca parameters with coefficients of 0.975 and 0.979 have the highest correlation with the GWQI index at a significant level of 1%. The results of this research have shown that the combined use of GIS, WQI, and GWQI indicators in evaluating the quality of groundwater and their spatial distribution in the studied area is useful and effective in selecting water resources for drinking purposes.