Optimization of DRASTIC Model for Vulnerability Assessment of Groundwater Resources Using Analytical Hierarchy Process (Case study: Andimeshk Plain)

Due to the increasing needs of human societies to groundwater supplies, the resource conservation and pollution prevention is necessary, especially in arid regions. Vulnerability assessment of groundwater can play a vital role in the protection of these resources. The main problem of DRASTIC model as the most widely used models for groundwater vulnerability assessment is the weighting. In this study, the weighting was modified using Analytical Hierarchy Process (AHP). To determine the optimal model, the correlation between the vulnerability index and the groundwater nitrate concentrations were determined using Simple Linear Regression Analysis (SLRA). The results showed that the optimal DRASTIC model has a better correlation rather than normal DRASTIC model. Also, to assess the risk of aquifer pollution, land use parameter added to the parameters and specific vulnerability aquifer map were prepared. The results showed that about 65 and 35 percent of Andimeshk aquifer contamination risk are very low and low, respectively.