Comparing the Accessibility of Rescue Centers in the Districts of Tehran Municipality after Catastrophic Earthquakes

In this research, the centers involved in relief operations in Tehran traffic area districts have been compared and the supply-demand ratio has been specified through a relation presented separately for each district. The supply has been evaluated based on three parameters: 1) No of relief centers, 2) congestion of the main road (the ratio of the length of the main road to the area of the district), and 3) the ratio of the length of the main road to those of the secondary roads. The demand has been considered based on the number of casualties waiting for relief per unit area of each district.
After delimiting the districts in the case study and extracting the network’s populations and roads information layers in the GIS, two road classes were specified: 1) main roads (capable of working under disaster conditions) and 2) secondary roads (capable of obstructing relief operations in needy areas). Next, the parameters were co equalized with their corresponding maximum values and scaled in the 0-100 range. The final results have been shown separately for each district (totally 32 in number) as the accessibility index. Accordingly, districts with indices smaller than 2 are considered as weakly accessible and those with indices more than 15 as properly accessible; districts with indices 2-8.5 have average accessibility.