Determining the vulnerability of the Khezri aquifer using DRASTIC and GODS method

Aquifers, as one of the most vulnerable water sources, are exposed to various contaminants in different forms, which detecting and controlling pollution in these resources are more difficult and costly than surface water. The best way to prevent their contamination is to identify polluting sources and vulnerable areas, prepare vulnerable zoning maps and adopt appropriate management policies. In this study, the DRASTIC and GODS methods are used to assess the Khezri area. Khezri area is one of the sub-basins of Khaf-Petergan Playa Iran, based on the political divisions of the country, and located in the southern Khorasan province near Qayen city, between the longitudes of 35 58 to 17 59 east and latitudes 41 33 to 6 34. The results of the DRASTIC for this area showed that a small part of the area has very low vulnerability, a very wide area of the plain has low vulnerability (69.68%), and the northwest and west of this plain have medium, high and very high vulnerability. Sensitivity analysis is also done in this area with two methods of eliminating the parameter and single parameter. In the single parameter sensitivity analysis, the aquifer environment parameter has the most effective weight and the parameter of the topographic slope percentage has the least effective weight in calculating the vulnerability index. In the map zoned by both methods, the points with high vulnerability are in the area of Khezri city and steel factory.