Use of Water Quality Index and Spatial Analysis to Assess Groundwater Quality for Drinking Purpose in Ardakan, Iran

Abstract

Introduction: Due to water scarcity and increased water consumption during the past years, the importance of water in terms of transmission of diseases, as well as Iran's climate, groundwater aquifers are known as the most important resources of drinking water supply. Using the Water Quality Index (WQI) is considered as strong managerial tool for decision making in water resource management. Therefore, the aim of this study was to evaluate the quality of groundwater in Ardakan for drinking purpose using WQI. Spatial analysis was conducted with the geographic information system (GIS). Materials and Methods: This is a descriptive, cross-sectional study to investigate the quality of groundwater in Ardakan for drinking purpose. Information on total dissolved solids (TDS), total hardness, pH, electrical conductivity (EC), bicarbonate (HCO3-), chlorine (CL-), sulfate (SO42-), nitrate (NO3-), calcium (Ca2+) and magnesium (Mg2+) of 24 wells was obtained from Ardakan Health Center. The characteristics of the stations were determined using the Global Positioning System (GPS) and transmitted to the map prepared in the GIS environment. The calculated values of the WQI were zoned in the GIS environment by Inverse Distance Weighted (IDW) method. Results: Based on the WQI, well no.5 has the best quality water (17.61), which has the lowest WQI, and the highest value of WQI was obtained for well no. 20 (156.86). Conclusion: The results of the study showed that none of wells have drinkable water, 13 wells had good quality water, and 11 wells had poor quality and should be treated for drinking.