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Top1. Introduction
Turkey is an earthquake-prone country and on this seismic belt, destructive earthquakes occur every 2-3 years on average. Earthquakes take the lead among all natural disasters in terms of the damage (60%) they do (İskenderoğlu et. al., 2003). Istanbul, the largest metropolis of the country, consists of one-seventh of Turkey’s population and half of the industrial potential. Urban earthquake risk has increased due to a series of reasons such as population growth, faulty construction and environmental degradation (Erdik and Durukal, 2007). There were losses of lives and damages due to the earthquakes throughout history. The results of earthquakes were more catastrophic especially due to ground conditions and construction features.
The Marmara earthquake, the last one of the many earthquakes that affects Istanbul, resulted with 18,373 losses of lives and 48,901 injuries. There were 364,905 damaged houses and workplaces; 96,796 of which collapsed-heavily damaged houses and 15,939 collapsed-heavily damaged workplaces, 107,315 of which moderately damaged houses and 16,816 moderately damaged workplaces, 113,382 of which slightly damaged houses and 14,657 slightly damaged workplaces (Parliamentary Research Commission Report, 2010). There were significant irreversible damages on transportation, communications, infrastructure and industrial facilities. It is believed that this earthquake occurred in 1999 is not the expected one. The expected one has more destructive results for Istanbul and its surrounding. There is a 50% change of an earthquake measuring 7.5 within 50 years according to the earthquake forecasting for Istanbul (Erdik, 2008).
85% of residential area in Istanbul lies on grade 1 seismic belt according to the Turkey Earthquake Zones Map inured with the decision No. 96/8109 dated 04/18/1996 of Council of Ministers. Therefore the earthquake which might occur on Sea of Marmara and its close surrounding can affect Istanbul, causing a large number of loss of lives and financial losses. In order to be best prepared for this upcoming earthquake, it is required to detect the type of structures and infrastructures that can be affected and the economic effects before and during the earthquake.
IMM (Istanbul Metropolitan Municipality) DCC (Disaster Coordination Centre) is responsible for conducting studies about planning and execution of every kind of measures before, during and after an earthquake in Istanbul according to sub-clause (b) of article No. 5 of Duties and Work Regulations. The units will be coordinated about determination of intervention areas after earthquake, the scale of damages etc. within the scope of IMM Disaster and Emergency Action Plan.
Accordingly, identification of risk areas, estimation of losses, and reduction of disaster risk are aimed in Istanbul region with a project. Various disaster plans will be applied according to various scenarios before an earthquake and damage distribution after an earthquake and scale of it using state of the art tech ELER software (Earthquake Loss Estimation Routine) which analyzes the loss of lives and damage distribution. In this manner, following the preparation of web-based data entry interfaces for ELER, which is desktop software, data sets needed were updated and results are submitted to users / administrations via web-based map programs.