Preparation of earthquake vulnerability map in district 1 of Tehran city

Earthquake is one of the most important natural disasters that can destroy human settlements in a very short time. According to the researches, the first 24 hours after earthquakes is the golden time to help the affected people because there is the greatest chance of the victims’ survival of the disasters. However, the dispatch of relief and rescue teams to the more vulnerable areas will reduce the number of casualties and injuries. For achieving these goals, it is necessary to identify the vulnerability map of the studied area in order to send the relief workers with prior knowledge to the area in earthquake occurrence as soon as possible.
This research is used the multi criteria decision-making (MCDM) approach based on spatial information system with the aim of identifying the most important factors exacerbating the earthquake induced vulnerability in district 1 of Tehran and providing a vulnerability map. The framework of MCDM includes environmental and manmade factors. The input bases map were provided in binary form based on vulnerability or damage to the different areas. At the end, two methods of Boolean and Index Overlay were used in order to combine the layers.
Findings: The results show that 12% of the total study area is classified in high vulnerability group; 45% in the middle group and the rest of the region (about 43%) in the low vulnerability group. In addition, the results showed that Darband area and its surrounding streets are considered as the most vulnerable parts of the first district of Tehran after earthquake regarding the research methods. This is because all vulnerability indicators in this area were undesirable. Depending on the vulnerability map, it is needed to extend the streets and passages in the central parts of the region due to the lack of transportation in the north of the study area and to establish standard roads in the northern parts of district 1of Tehran. Moreover, in order to prevent disasters all standards must be observed during construction due to the geological map prepared and the vulnerability of the major part of this region.
According to the results, management plans must be made before the earthquake in order to reduce vulnerability in high vulnerability areas including providing the optimal relief and care centers than crisis and vulnerable centers also applying building standards especially in the adjacent areas of the passageways. After the earthquake, relief workers should be sent to the vulnerable areas with prior knowledge of the affected area and using vulnerability maps.