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In the study, stair streets in Istanbul were evaluated within the scope of disaster risk and accessibility. The transportation network of the settlements plays an important role during the disaster and emergency in terms of safe evacuation and reaching to the emergency units. Determining existing risks and taking preventive measures for safe use of transportation networks before a disaster therefore become important. Stair streets, shaped by the topography and the use in their surroundings, are an important component of pedestrian transportation. The structure of street with stairs comes with its own set of challenges. Stair streets that are integrated with different materials and environmental texture in different regions need to be evaluated in terms of disaster risks today. In this context, 26 samples selected over 100 steps from different districts of İstanbul with high earthquake risk were examined. The stair streets were evaluated in on-site examination and observation in terms of their relationship with the topography, landscape, building connections, step features, purpose of use and intensity and their disaster risks such as flood, fire and especially earthquake. Non-structural building problems that may lead to outdoor injuries associated with earthquakes were taken into account. The existing drainage system in the stair streets were evaluated in the context of flash flooding. Buildings around the stairs were evaluated in terms of the existing infrastructure considering building materials, type of use and fire risks. In most of the streets studied, preventive measures need to be developed regarding flooding and fire risks. The overall research results show that the stair streets in Istanbul should be studied in detail in terms of emergency and disaster risks.

Many settled areas in Turkey and across the globe suffer economical and social losses resulting from natural disasters such as earthquakes, floods, hurricanes and landslides. In this study, a vulnerability assessment model has been developed for earthquake prone areas in Turkey. The vulnerability assessment model includes ground factors, a building’s physical conditions, building evacuation and social (demographic and socioeconomic) aspects of the settlement. The ground vulnerability factor is calculated using factors such as the earthquake zone, soil classification, land sliding and liquefaction threats. The physical vulnerability factor depends on the structural and non-structural threats of the building; the building evacuation vulnerability factor includes the position and structural system of the staircase, the width and natural illumination of the evacuation route, the size and opening of the building exit doors to the street and the distance of the building to the closest open area. The social vulnerability factor considers the age group, gender, family type, education, ownership, income etc of the building users. This vulnerability assessment model is applied to a case study - that of the Avcılar district of Istanbul. Forty different reinforced concrete residential buildings (349 apartments) of 1225 people are assessed using the develop checklist. In order to evaluate the checklist and to assess the importance (relevance) of vulnerability factors, a questionnaire is forwarded to various related professional groups (architecture, urban planning and civil engineering). The results of the questionnaire are examined using SPSS software with factor analysis. According to the results, most of the samples in the case study area can be classified as high vulnerable.