| Popis: |
One of the most important and perilous groundwater contaminants is nitrate, which is considered a potential environmental risk in Iran and an international issue globally. The study area is the Karaj unconfined aquifer, Central Iran, subjected to quantity and quality hazards due to unbalanced urban, industrial, and agricultural developments. Evaluation of the vulnerability condition of this aquifer against nitrate as the Contamination index is essential since the most amount of consumption water in the area is provided from groundwater. The study aims to detect vulnerable zones of the Karaj aquifer using DRASTIC + L and Modified VEBHAT vulnerability models. The weighting of the parameters has been performed employing the recent Multiple-Criteria Decision-Making (MCDM) methods, including Stepwise Weight Assessment Ratio Analysis (SWARA) and Best Worst Method (BWM). The results demonstrated that the most vulnerability had occurred from the east to the south of the aquifer (high to super-critical), including urban and residential areas, regarding both the vulnerability models' plots. The plots of the two methods are similar and did not exhibit considerable differences. The Modified VEBHAT has more certainty than the DRASTIC + L and has optimized and improved the DRASTIC + L model because the most vulnerable zone in the output plots of the Modified VEBHAT model is in the east of the aquifer, which has good agreement with the nitrate contaminant mass with the highest concentration. |
