Recognizing and Zoning the appropriate areas of the Effective Environmental Dangers on Physical Development of Ilam City

Natural hazards are threatening events which result in a large number of casualties and major financial losses. Therefore, it is necessary to carry out scientific studies and research on this subject. The current study aims at identifying and zoning the environmental hazards influencing the physical expansion of Ilam City based on a descriptive analytical methodology and field observations. The area selected for the study is the City of Ilam and the statistical population of the study includes the experts of urban management and crisis management whose comments and opinions will be used for determining the  importance of the selected criteria. The data analysis methodology in this study involves combining digital layers in GIS, fuzzy hierarchical analysis, and TOPSIS. The results of the study show that among all the natural hazards common to the middle section of the Zagros Mountains, Ilam City is mainly influenced by the danger of flooding. After evaluating the lands in the urban area of Ilam, it is observed that the expansion path Ilam City has gone through during the recent decades has beenwithout any consideration for this major phenomenon and the physical expansion of the city has been in the areas with a high risk of flooding. Two areas with very high risk, with the total area of 5.33 and 2.18 hectares, are the regions of the city which suffered severe damages in the recent flooding and they are still facing a very high risk of flooding. The safest areas for expansion in Ilam City are the southern zones of the city (towards Cheshmeh Kaboud Village) which have a desirable physiographical state and acceptable risk level against  flooding.