Flood hazard zoning in the Razey chay water basin using the VIKOR model

Flood is one of the greatest and most common forms of natural hazard and every year around the world, there is a huge loss of life and financial loss. In this study, at first, 8 effective factors in catchment flooding were: slope, elevation, lithology, distance from fault, precipitation, land use, distance from river and soil identification. Then, information layers were prepared by GIS. The evaluation and standardization of the standard maps in the IDRISI software was done in conjunction with the fuzzy method. In the next step, the factors studied were considered as critic weights. The final analysis and modeling was done using the Vikor method as a multi-criteria decision analysis method. The results of this study also showed that among the effective factors in causing flood factor are slope factor with weight factor of 0.18, height factor with weight factor of 0.17 and land use factor with weight factor of 0.13 respectively are in the study basin. In addition, 15.49% and 16.47% of the basin area are in the very high risk category, respectively, which indicates the high potential of this basin for flood. According to the results, the factors slope and elevation and land use have the greatest impact on flood formation in the Razey Chay basin. Mostly, high-risk areas are located in the northwest and northwest basin. Therefore, conservation measures, watershed management and management of the basin are necessary studies.