Determining the vulnerability of Barandouzchi aquifer Plain, Urmia, using the combination of DRASTIC, SI, AND SINSTAC Indices

Due to the increasing need of human societies to groundwater, especially in arid and semi-arid regions such as Iran, Protection and prevention of pollution of these water resources are considered necessary. For this purpose, evaluating the vulnerability of groundwater can play a vital role in protecting and exploiting these resources. In the Barandozhay plain, due to the high agricultural activities, chemical fertilizers, pesticides application, and low depth of water table, there is the probability of aquifer contamination. For this purpose, at first, the potential of contamination of groundwater resources in the plain was studied using DRASTIC, SINTACS and SI models and then, the final map of vulnerable areas was prepared using the combination method. Comparison of the results obtained from the models with nitrate data based on the correlation index (CI) indicated that the combined method of the three models had more correlation than individual models of DRASTIC, SINTACS, and SI. Based on the combined method of the three models, 25, 40 and 35 percent of the Barandozchai plain aquifer area are located in the low, medium and high vulnerability range, respectively. Plain water is suitable for drinking according to the international standards of nitrates.