Investigating the Vulnerability of Street Networks Against Air Rids Using IHWP and GIS (6th Zone of Tehran)

Today, physical expansion and high density of great cities, due to narrow access roads, large distance from medical care centers and location at areas with high seismic risk, will lead to a perilous and unpredictable situation in case of the air raids Occurrence of air raids to these cities, along with lack of attention to principles of passive defence will destroy the functionality of street networks and cause large amount of casualties and financial damages. Zone 6 of Tehran, with 220,000 population and 20 km2 area, is one of the main municipal zones of Tehran. In this paper, vulnerability degree of street networks in zone 6 against the air raids is calculated through overlaying maps and data in combination with IHWP method and GIS. The results shown that moving on from north to south of the zone, the vulnerability increases. Likewise, highways and streets with substantial width and low building and population density hold little values of vulnerability.