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چکیده
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Preparing a map of flood hazard is susceptibility an important step in flood risk management. Therefore, it is necessary to use methods that reduce errors and increase the accuracy of identifying flood hazard areas. This study was conducted to prepare a map of the flood hazard index (FHI) and evaluate subjective and objective multicriteria decision analysis (MCDA) weighting methods. Talar basin, which is located in the north of Iran, has been investigated as a case study for this research. Seven factors influencing flood, including elevation, slope, flow accumulation, distance from the river, rainfall intensity, land cover, and geology, were considered to create a flood hazard map. The weighting of these factors has been performed by the Analytical Hierarchy Process (AHP), sensitivity analysis of AHP (AHPS), Shannon Entropy (SE), and Entropy-AHP. The maps created with the data of past floods were validated with the Accuracy index and Kappa index methods. The results showed that the FHI-SE method was more accurate than others, with an accuracy value of 0.979. FHI-SEA, FHIS, and FHI methods were placed in the next priorities, respectively. Based on the SE method, the factors of distance from the river, elevation, and slope have respectively obtained the highest weight value in creating the flood hazard index map. Distance from river variable was classified separately for mountain and plain regions to reduce the overestimation of flood hazard areas in mountainous areas. The objective weighting method has provided higher accuracy than the subjective weighting method, such as AHP.
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