Seismic vulnerabilities and risks for urban mitigation planning in Turkey

Chronic seismic hazards and resulting secondary impacts as natural conditions of the country, and the loss of robust building and prudent settlement practices as aggravated by rapid population growth make cities the most vulnerable geographical and social entities in Turkey. For the development of risk reduction policies, an essential step is to prioritize settlements according to their vulnerability levels. This could be determined by hazard probabilities and attributes of the building stock of each settlement. Measurement of vulnerability levels allows the ordering of settlements into risk categories. Vulnerability levels of settlements are then assumed to depend on a number of attributes of cities to explore whether vulnerability could be related to a set of urban properties. Results of statistical analyses indicate that total building loss is related to the ratio of population over the total number of buildings in mid-range settlements, and directly related to population in metropolitan cities. Relative loss on the other hand is related with the rate of agglomeration and development index in almost every size category of settlements. Observations provide guiding principles for effective mitigation practices in Turkey by ordering settlements and offer means of differential implementation. These could contribute to improved safety measures in urban standards, building codes, building supervision procedures, insurance systems, and investment priorities.