The study and evaluation of the vulnerability rate of eroded texture of Ilam city to earthquakes

Earthquake is considered to be the most destructive natural disaster causing/which causes human casualties and considerable economic losses in our country,Iran.The injuries and damages are far more severe in older city tissues because of their older tissues anddistinctive and unique structures. However, these tissues as a part of the city are a symbol of early human civilization.Since these tissues are vulnerable to natural incidents, especially earthquakes, their repairment and sustenance seem to be of special importance. The old texture area of Ilam is 374 hectares, 19% ofwhich covers old sectors and central tissues. Descriptive-analytic and field method was used to analyze the data.
The aim of this study was to review and evaluate the vulnerability rate of the old texture of Ilam city in terms of suchindexes as types of materials, buildings age, number of floors, type of use, occupancy level, quality of buildings, buildings area, population density, and streets width.
The results showed that construction materials accounted for the largest weight while other factors were just a function of the materials used for construction. As we use more durable construction materials, while observing engineering principals,for urban construction, the buildings will be less vulnerable to earthquakes. Vulnerability output map indicated that in the total area, with the exception of passages, the vulnerability levels were as follows: 8.9 percent too much vulnerability, 59% high vulnerability, 23% moderate vulnerability, 3.6% low vulnerability and 5.5% very low vulnerability. Totally, based on the above indexes, 67.9 percent of the old texture area are vulnerable.