Assessment of Status, Processes, and Geochemical Sources of Aquifer Using Water Quality Index, Graphical Approaches, and Multivariate Statistical Analyses- A Case Study: Shabestar Plain

Proper knowledge of groundwater geochemistry and identification of the risk factors for the aquifer system is very important to control and improve the management of groundwater resources in arid and semi-arid regions.

Sampled data during six years from 2014 to 2019 were used to assess the temporal variation of geochemical parameters of the wells in the study area. Water quality index (WQI), Piper diagram, Wilcox Diagram, and Gibbs Diagram were employed for evaluating the status of groundwater using sampled data in 2019.

The results showed that the total hardness (TH) exceeded the standard value proposed by WHO for six years. The study area is categorized in a moderate range in terms of drinking water quality. Calcic-bicarbonate and temporary hardness (Ca-Mg-HCO3) were obtained as the hydrochemical factor and type of the groundwater in most of the samples, respectively. A little salty and salty water were identified as the status of groundwater quality for agricultural purposes. Rock dominance was also determined as the controlling factor in groundwater of the study area. The results of multivariate statistical analyses indicated that wastewater, fertilizers, agricultural effluents, and geological structures were the most important sources of entering the hydrochemical parameters.

The results of this study indicated that anthropogenic activities, geology structures, and the effects of Urmia lake are the most important factors to the concentration of physicochemical parameters in the groundwater.