Vulnerability Sensitivity Analysis DRASTIC Method

Pashminezar Plain is located in Northwest of Khuzestan province at a distance of 150 kilometers from Ahwaz city whose main water source is underground water. Due to the large expansion of agricultural activities, the quality of groundwater is affected by chemicals, especially nitrates. Therefore, vulnerability assessment is important in managerial decision making of this plain. In this regard, for potential contamination of groundwater resources in the Pashminezar Plain, the two methods DRASTIC and GODS were used. In the DRASTIC method, seven parameters of depth, nutrition, Aquifer environment, soil, topography, unsaturated environment, and hydraulic conductivity were used. Results of DRASTIC Model showed that about 1.31 percent is in the range without the risk of vulnerability, 51.6 % in the very low vulnerability range, 45.52 % in the range with low vulnerability and 1.5 % in the range of low vulnerability to average. The results of sensitivity analysis of removing the map, as well as single-parameter sensitivity analysis, showed that the main parameter affecting the vulnerability index is the unsaturated zone