Evaluation of Groundwater Quality in the Mineralized Fields by Analytical Hierarchy Process‐Based Water Quality Index

In this study, an epithermal goldfields‐water quality index (EGF‐WQI) and the associated classification system have been proposed to define drinking water quality of the water resources in regions where epithermal gold mineralization exists. In this context, two hydrogeochemical data sets from 15 water resources are used. EGF‐WQI is designed using 21 different criteria under 4 main groups and 15 alternatives. To determine the importance and efficiency values of the criteria, analytical hierarchy method (AHP) is used. The water quality classification system is defined by 4 different categories, namely, “very good,” “good,” “acceptable,” and “inappropriate.” In order to ensure consistency of the findings, efficiency scores of the AHP method are compared with the results obtained from the technique for order preference by similarity to ideal solution and data envelopment analysis models. The index results obtained from AHP processes are converted into water quality distribution maps by using the Kriging interpolation method. EGF‐WQI results are observed to be compatible with the water quality standards developed by organizations such as the World Health Organization and Turkish Standards. EGF‐WQI can be used as a reliable and valid index to evaluate the water resources in regions where alteration and mineralization are present. The developed water quality index (WQI) epithermal goldfields‐WQI using 21 criteria under 4 main criteria groups gives valid and practical results to assess water quality and temporal quality change of water resources in mineralized areas. Moreover, it provides an idea of whether there is any remarkable change in the quality of water resources with a single score and/or classification system.