One of the most important problems in Iranian cities is their vulnerability to natural hazards such as earthquake, storms, etc. This is particularly more critical in old part of the cities due low conditions of its physical fabric considering the quality ofmaterials, less permeability, unrenovation, etc. Purpose:We aim to identify the most deterioration parts within the old texture of city of Zanjan using GIS and relating techniques. We also try to recognize the main reasons which caused these deterioration problems. Methods: To do this, we first conceptualize eleven physical-spatial factors. These factors have been analyzed using fuzzy logic and IHPW (Inverse Hierarchy Process Weight) within GIS. Results and conclusions: Results of the model which has been applied on the city of Zanjan’s old fabric illustrate that a fuzzy approach is a basic tool to identify vulnerability. Its application to the problem helps to unify relevant theory and practice. It also generated maps of vulnerable spots that can be more adaptable to changes and can greatly assist planners and policy makers in decision-making.
