Groundwater vulnerability assessment with using GIS in Hamadan–Bahar plain, Iran

Vulnerability assessment to delineate areas that are more susceptible to contamination from anthropogenic sources has become an important element for sensible resource management and land use planning. It has been recognized for its ability to delineate areas that are more likely than others to become contaminated as a result of anthropogenic activities near the earth's surface. The main methods of mapping and assessing intrinsic vulnerability in porous media are the following: SI, GOD, SINTACS and DRASTIC. The basic purpose of these maps is to divide an area into more classes, each of which will represent a different dynamic for a specific purpose and use. These models have been used to map groundwater vulnerability to pollution in Hamadan–Bahar aquifer. The results showed in models of DRASTIC, SI, GOD and SINTACS, respectively, 7.1, 44.21, 29.56 and 20.16 percent of the areas are high potential vulnerabilities. According to the model DRASTIC at study area, 33.6% of has a low class of groundwater vulnerability to contamination, whereas a total of 29.4% of the study area has a moderate vulnerability. The final results indicate that the aquifer system in the interested area is relatively protected from contamination on the groundwater surface. The correlation between models shows that DRASTIC model has the highest CI, which is 141, and the GOD model has the highest CI, which is 139. Also, the highest CI for SINTACS and SI is 137 and 136, respectively. Therefore, DRASTIC model is the best model among these models for predicting groundwater vulnerability in Hamadan–Bahar plain aquifer.