Groundwater Vulnerability Assessment Using DRASTIC and SINTACS Models in GIS (Case Study: Karun Township)

Existence of important sources of pollutants and points of human activities on the ground and the penetration of these pollutants into aquifers, reduces the quality of groundwater, so in the management of groundwater resources, pollution prevention these waters are essential. The groundwater of Karun Township in Khuzestan province is always exposed to pollution due to the prosperity of agricultural and industrial activities in that area. Therefore, the aim of this study is to evaluate and zoning the aquifer vulnerability of the region using DRASTIC and SINTACS models. By mapping and combining hydrogeological parameters effective in the transfer of contamination to the aquifer, vulnerability maps of the two models were prepared in GIS software environment. To validate the models used, the measured amounts of nitrate in the wells in the area were used and the Pearson correlation coefficient between the models and the nitrate layer was calculated and determined. The results showed that the vulnerability index of the DRASTIC model varies Between 68 to 215 and the vulnerability index of the SINTACS model varies between 52 and 195. In the DRASTIC method, 485.2 hectares of the area without risk of pollution, 751.6 hectares with very low vulnerability, 3305.5 hectares with low vulnerability, 12411.7 hectares with moderate vulnerability, 11191.2 hectares with Moderate to high vulnerability, 9427.3 hectares with high vulnerability, 58861 hectares with very high vulnerability and 478.5 hectares are completely susceptible to infection. In the SINTACS method, 455.4 hectares of the area without risk of pollution, 789.1 hectares with very low vulnerability, 32281 hectares with low vulnerability, 12426.7 hectares with medium vulnerability, 11169.4 hectares with Moderate to high vulnerability, 9449.3 hectares with high vulnerability, 5844.2 hectares with very high vulnerability and 495.7 hectares are completely susceptible to infection. Also, the correlation of groundwater nitrate map with DRASTIC and SINTACS models was 0.68 and 0.51, respectively, which indicates the higher capability of the DRASTIC model than the SINTACS model for the aquifer in the study area.