Preparation of Flood Susceptibility Map using Multi-Criteria Spatial Analysis and Data Fusion (A Case Study: Maneh and Samalqan County)

The flood is the most important natural disaster that causes human and financial losses every year, then its management is very important. The most basic step in flood disaster management is the preparation of a flood susceptibility map, which integrating the geospatial information system and multi-criteria decision making is an efficient approach to handle it. In order to spatially model flood susceptibility, the present study has presented an approach of fusion the weights of the effective criteria on flood susceptibility using the Dempster-Shafer information fusion theory (DST). The purpose of the fusion of the weights of the criteria is to increase reliability, reduce the uncertainty of the weighting process, and increase the accuracy of flood susceptibility modeling. The present research has presented a hybrid weighting method by integrating the results of two weighting methods (Analytical Hierarchy Process (AHP) and Best-Worst Method (BWM)). The hybrid weighting methods of previous researches are mainly based on simple mathematical operators, and complex operators such as DST used in the present research are less used. The results of the fusion of the weights obtained from the two weighting methods of AHP and BWM indicate the very high weight of the flow accumulation criterion (0.437) and the very low weight of the vegetation index criterion (0.004). Comparing the results of the research with the facts of the studied area showed that the presented hybrid weighting approach with 96% accuracy Compared to each of the basic weighting methods used, is of higher performance. Also, the susceptibility modeling resulting from the new BWM weighting method has been more accurate compared to the common method of the AHP. According to the results of the research, more than 92% of the studied area has moderate to high flood susceptibility and less than 8% of the area has less than moderate susceptibility, which indicates that the studied area is prone to flooding.