Assessment of the pollution potential of groundwater in Khaledabad Badrood aquifer using DRASTIC model

Surface water resources are limited in many regions in Iran, so groundwater resources are considered the most suitable resources for supplying water. The excessive use of chemical pests and fertilizers has resulted in groundwater pollution. Therefore, it is necessary to determine the vulnerable areas to preserve these vital resources. In this study, the DRASTIC model was used to analyze the vulnerability of groundwater in Khaled-Abad- Bardood plain. Seven factors including the nutrition of pure water, groundwater depth, unsaturated area, soil texture, Hydraulic conductivity, aquifer media, and topography were used in the model. After the preparation of 7 layers, appropriate weight was assigned to these factors. Finally, by mapping these layers and applying their weight to them in ArcGIS 10.5, the vulnerability maps of the groundwater were generated. To validate the model, sampling and measuring the amount of nitrate for 13 wells located in the Khaled-Abad-Bardood plain were conducted. The results indicated that 22% of the plain was vulnerable based on the DRASTIC model, which was located in the vicinity of Bardood city and its eastern areas. The results also showed that the correlation of the DRASTIC vulnerability map with the measured nitrate was found to be 74 %.