Assessing pollution risk in ardabil aquifer groundwater of iran with arsenic and nitrate using the SINTACS model

Abstract

Groundwater vulnerability assessment is a general method for studying groundwater pollution. This study aimed to assess the pollution risk of groundwater with nitrate and arsenic. Risk is comprised of two parts: Calculation of occurrence probability map and composition of occurrence probability map with groundwater vulnerability model. To draw up a groundwater vulnerability map, the SINTACS model was used. The correlation of the model with nitrate and arsenic concentrations was investigated. The correlation coefficients of the SINTACS model with nitrate and arsenic were r = 0.70 and r = 0.85, respectively. According to sensitivity analysis, we concluded that the SINTACS model had the least sensitivity to hydraulic conductivity. To prepare the occurrence probability map, nitrate and arsenic concentrations were combined separately with the groundwater recharge potential model. Finally, the risk map was prepared by combining the occurrence probability map and groundwater vulnerability with the SINTACS model. The results revealed that 14.72% of the study area had a high risk of nitrate and 35.33% had a high risk of arsenic. The areas with high pollution risk are those which are considered agricultural lands based on the land use map.