Comparison of the DRASTIC + L and modified VABHAT models in vulnerability assessment of Karaj aquifer, central Iran, using MCDM, SWARA, and BWM methods

One of the most important and perilous groundwater contaminants is nitrate. The study area unconfined (free) aquifer Karaj, located in central Iran, which subject to quantity quality hazards due unbalanced urban, industrial, agricultural developments. Evaluation vulnerability condition this against nitrate as contamination index essential since consumed water provided by groundwater. This paper describes a new model that integrates obtained DRASTIC + L (V), extraction rate (E), head changes (H), media (A), transmissivity (T), i.e., Modified VEBHAT model. aims detect vulnerable zones Karaj using models. weighting parameters has been performed employing recent Multiple-Criteria Decision-Making (MCDM) methods, including Stepwise Weight Assessment Ratio Analysis (SWARA) Best Worst Method (BWM). results indicated highest levels occurred from east south (high super-critical), urban residential areas, regarding both models’ plots. plots two methods were similar did not exhibit significant differences. In addition, had more certainty than optimized improved because zone output was aquifer, good agreement with contaminant mass concentration.