This study uses a GIS-based method to delineate areas that are more susceptible to contamination originated from surface water infilteration at the aquifer of Shushtar-Mianab. The objective of this work was development a DRASTIC model in order to delineate vulnerability of the aquifer and verifying the results based on groundwater samping and detecting 4 types of pesticides which has been infilterated to the groundwater.
The aquifer is classified to four groups of low (11%), medium (75%) and high (14%) vulnerability area mainly due the low depths of waters based on DRASTIC method.
In this study groundwater sampling has accomplished in the 37 points of the aquifer and 4 types of pesticides has detected using in-tube solid-phase detection method and the model has calibrated based on the analysis results. Then the aquifer has classified to four groups of low (18%), medium (67%) and high (15%) vulnerability area mainly due to the low depths of waters based on the calibrated DRASTIC method.
Sensitivity analysis has accomplished by two methods: Single-parameter sensitivity analysis and removal sensitivity analaysis. Hydraulic conductivity and groundwater depth have minimum and maximum effective weights respectively based on the Single-parameter sensitivity analysis. Removal sensitivity analaysis method at the other hand suggests that maximum changes in the vulnerability index occurs by removing groundwater depth parameter with average change index 3/3%.