Assessment and modeling of groundwater quality for drinking, irrigation, and industrial purposes using water quality indices and GIS technique in fasarud aquifer (Iran)

One of the main issues in arid and semi-arid areas like Iran is water shortage and environmental deterioration. This study aimed to address the groundwater quality for drinking, irrigation, and industrial consumption by integrating the water quality indices with the geographic information system (GIS) for Fasarud Plain groundwater quality interpretation in southern Iran. Hence, 186 borehole water samples were collected in wet and dry seasons, and all these samples were subjected to lab experiments for pH, EC, TDS, TH, and major cations and anions using standard techniques. The outcomes of the Piper diagram indicated that in both seasons, the water type in the research region is Ca-Mg (HCO 3 ) 2 , CaCl 2 , and mixed. In this study, the suitability of groundwater for drinking was determined by using WHO guidelines and Water Quality Index (WQI). The results indicated that despite the decrease in total dissolved solids in the wet season, the concentration of high ionic strength inorganic components such as nitrate and bicarbonate increase and results in raised electrical conductivity. The spatial distribution maps for the most water quality variables revealed that the not-permissible values were found, during both seasons, in the south, southwest, and northeast parts of the aquifer. According to WQI in both seasons, most plain areas have excellent and good quality water for drinking purposes, except the regions at south and west of the study area with poor quality (10.26% and 8.62% in the dry and wet seasons, respectively). The classification of water for irrigation based on the US salinity diagram showed the medium-to-high salinity and low SAR class in both seasons. In addition, based on the corrosivity ratio, the groundwater quality in most areas of the plain is in an unsafe zone in terms of industrial uses in both seasons (81.97% and 88.63% in the dry and wet seasons, respectively). In general, the reduction of water quality for potable, agricultural, and industrial uses from the dry season to the wet season shows the destructive effect of anthropogenic activities such as agriculture on groundwater quality.