Evaluation of Groundwater Quality Urmia Plain to drinking water purposes using GQI method in ArcGIS software environment

Today, the growing population on the one hand, and the limitation of fresh water resources, on the other hand, have led to an assessment of water quality in terms of quality and quantity, especially in arid areas, in a special place in groundwater studies. So that the supply of water needed for drinking with proper quality and without any kind of pollution, has become a human challenge. One of the indicators for assessing water quality is the concentration of the main ions in water. The concentration limit for these ions in drinking water has been determined by the World Health Organization (WHO). One of the most commonly used methods for assessing drinking water quality is the Schuler diagram, which allows water to be checked at a specific point in the area. Hence, the five selected samples representing the entire aquifer are in good quality. But, in order to investigate the spatial variations in drinking water quality across the entire aquifer area, the Groundwater Quality Index (GQI), presented in 2007 by Babyker et al., Was also used. The results of this study showed a value of 74 to 95 percent, the groundwater of the studied plain has good drinking quality standards.