The Vulnerability Assessment of Urban Housing in Earthquake against (A Case Study: 9th district of Tehran municipality)

Intro duction Tectonic features of the Iran, has raised the earthquake as one of the most destructive causes of destruction of human life. Historical review shows that large areas of Iran have been suffered by natural disasters and caused heavy human and financial loss. Because of this important issue it is needed to reduce earthquake vulnerability. The city of Tehran as one of the largest and most important cities, due to the geographic location of this city on several active faults and historical records of these faults activities can be said to face a massive earthquake in near future, so the 9th district of Tehran municipality, is selected as the study area. In this research TOPSIS Fuzzy model is used to assess and analyze vulnerabilities in the study area, considering different earthquake intensities. 2- Theoretical Bases Basic concept of TOPSIS is based on the belief that selected options should have lowest distance from positive ideal points and most distance from negative ideal points. Since many of the variables related to the issue in the real world are linguistic and qualitative variables, so in these issues it is better toapply Model Fuzzy Decision Model, such as TOPSIS Fuzzy model, which shows the importance of standards and options performance according to the various characteristics, using fuzzy numbers, instead of integers. 3- Discussion The results of the regions vulnerability assessment used shows that 73.66 percent of buildings in this area have moderate vulnerability, that are the northeast, east and southeast parts of this regions that included a maximum number of housing. Then, assessment of different earthquake intensities, the building damages were evaluated in the intensities of 6 and 7 and 8 Mercalli intensity scale. The results show that in intensity 6 of Mercalli scale, buildings damage in ranked between zero and one. In intensity 7, buildings damage was ranked between one and two and in intensity 8 buildings damage was ranks higher than two. 4- Conclusion Many models are presented to analyze and evaluate the seismic vulnerability of cities; and various researches have been done. In those works inside the country the investigated area was not small. Also, in today's world, in many variables related to current issues of real world are qualitative and linguistic, So, in these issues it is better to use fuzzy models, No doubt regional vulnerability is related to human characteristics in that region and a reflection of human behavior and human management practices, because the construction and implementation of engineering principles in construction depend on management comments and thoughts, After so, in any investigation, the applied models shoud be compatible with the study area conditions. 5- Suggestions - Create an organized GIS database of cities, analysis of vulnerability of earthquake-prone areas, designing softwares for vulnerability analysis and assessment based on the analyzed model in this study. - Vulnerability assessment of Tehran and other earthquake-prone regions of the country, to make necessary measures to reduce vulnerability in these areas.