The weight of interaction of mining activities: groundwater in environmental impact assessment using fuzzy analytical hierarchy process (FAHP)

Mining operations threaten the environment if the monitoring and controlling steps are not implemented completely. One of the important methods for control of the environmental situation in the mining district is the environmental impact assessment (EIA) method, which is performed by matrix calculations. In this method, the environmental problem is broken into several parts as the Impacting Factors that is evaluated their influences on Environmental Components by the mathematical calculations. For these calculations, the weight of each Impacting Factor must be evaluated by using comprehensive scenarios that are involved all the predicable environmental issues. Based on literature, it has not been organized a comprehensive scenario about "Interference with groundwater" as an Impacting Factor yet. By consideration of the importance degree of groundwater and its role in supply the drinking water resource, it is felt to demand for an organization a developed scenario in relation with groundwater pollution in mining district. Therefore, the main aim of this study is developing a new scenario to weight the "Interference with groundwater" in EIA matrix. For this purpose, the 8 criteria and 63 subcriteria are defined and their weights are determined using the Fuzzy Analytic Hierarchy Process. The proposed scenario can be successfully evaluated the weight of "Interference with groundwater" Impacting Factor more exactly than the former one, because it considers 8 criteria and 63 subcriteria instead of 2 criteria in the former scenario. Finally, the application of proposed scenario is illustrated by an imaginary ideal case study. Such studies can be used by mining engineers and planners to design an appropriate environmental plan for the mining districts.