Physical Vulnerability Assessment of Urban Fabrics against Earthquake by RADIUS Method (Case study: Shiraz City, 3rd Municipal District)

Iran is being crossed by several major fault lines that cover at least 90% of the country and it is a seismic prone region. The country has been host to a long series of devastating earthquakes that have resulted in heavy casualties and damages. Due to the geographic location of Iran (located on an earthquake belt of Alps- Himalaya) many natural disasters occur annually. The Iranian plateau is subject to most types of tectonic activity, including active folding, faulting, and volcanic eruptions. It is well known for its long history of disastrous earthquake activity. During the last several centuries various regions in the country have experienced destructive earthquakes. Not only these earthquakes have killed thousands, but they have also led to waste of valuable natural resources. Since 1900, at least 126,000 fatalities have been resulted from earthquakes in Iran. The expansive infrastructures, along with the high population density make cities highly vulnerable to the severe impacts of natural incidents. So, the need for evaluating and visualizing the vulnerability of urban areas becomes a necessity.

Shiraz, which is one of the biggest urban areas, is located in the south part of Iran. This city is more than 4000 years old. Shiraz lies in Fars Province, a central area for Persian civilization. Due to exposure to several active faults in and around the city the greatest risk is the risk of earthquakes. The major faults in Shiraz region and its vicinity are Sabzposhan, Kohenjan, Sarvestan and Karehbas. The 1824 earthquake had destroyed parts of the town. The 1860 and 1890 earthquakes had ruined historical buildings of this city; Shiraz was renewed and flourished again. In 1972 there was an earthquake with Magnitude of 6.9 in Ghir and Karzin with a lot of people killed and injured. There were again huge earthquake in Fars Province recently (3 years ago in Lamerd and 2 years ago in Shiraz) in the area. The last advices from Persia state that a severe earthquake has leveled Shiraz with the ground, and 15,000 persons perished in the ruins. So, the study aims to: a) identify vulnerabilities in the 3rd municipal district of Shiraz and the amount of physical damage can be caused by an earthquake with a magnitude of 7.4: b) determine the extent of casualties caused by the earthquake.