Flood Zoning Using HierarchicalAnalysis andFuzzy Logic in GISCase Study: Ilam City

Various factors such as overcrowding, land leveling and occupation of rivers along with climatic factorsin urban areas have caused urban flooding .The city of Ilam is no exception; This has caused a lot ofdamage to residential areas, roads, fields and farmlands over the past few years. The purpose of this studyis to evaluate and zoning flood-prone areas in Ilam. For this purpose, criteria such as slope, geological features,topography, streamflows, soil and land use were selected, weighted and standardized by hierarchicalanalysis and fuzzy model.Then, zoning map with overlapping the weighted maps for each criterion was preparedin the GIS. Final analysis of the map shows that the north and northwest areas have the highest potentialfor flood risk. The results also showed that 0.60% of the total area are in very high vulnerability categoryand 6.29% in high vulnerability class, 20.92% in the average vulnerability class, 50.23% in low vulnerabilityclass and 21.95% in the very least vulnerable category.