Physical Vulnerability Comparative Analysis of the Gorgan City Center and peripheral texture against Earthquake

The most important factor in the urban textures vulnerability during an earthquake is the physical characteristics such as the age of the building, materials, number of floors, width and the degree of vulnerability. Accordingly, the purpose of this study is the vulnerability analysis of Gorgan texture in terms of physical indices and comparison of the its central and peripheral regions against the earthquake. In this research, cluster and Rao method (R.H.C) was used. The research statistical population consisted of 400 buildings in Gorgan which is determined by the Cochran formula. The findings of the research show that Based on the results of regression correlation test, the relationship between the vulnerability variable and width of the passageway is direct and medium, with type of materials is strong direct, with the number of floors is strong direct. Finally, the relationship between the variable of vulnerability with the number of units in buildings is the direct and poor. Based on regression method, the building materials and number of floors, the age of the building, access to the passageway, and finally the number of residential units in the building have the greatest impact on physical texture vulnerability of the urban areas respectively. The results of the physical vulnerability comparison of Gorgan city the central and peripheral textures indicate that the density average of residential units (equivalent to 1.92) is lower in the central texture. The age of the central texture building (more than 2/31) is higher. The floors of peripheral texture building (up to 1/29) are higher. In terms of unit’s accessibility index, the peripheral texture average is 2.33, so the buildings of this section have more accessible access to wider passages. The final index of the buildings vulnerability in the central and peripheral area indicates that the peripheral texture average is 2.42 and, consequently, the buildings of this section are less vulnerable.