Evaluation of seismic hazards on worn and unstable tissues of Bojnourd city

Earthquakes are one of the hazards that always threaten the environment of cities. One of the best ways to mitigate in natural hazards is prevention. The city of Bojnourd, the capital in Northern Khorasan province in northeastern Iran, with a population of 211,000 people, is located between the two sedimentary-structural areas in Kopeh Dagh, Hezar Masjed and Aladagh-Binalood, which is considered as one of the most dangerous areas in terms of seismicity. The present study is applied in terms of purpose and descriptive-analytical in terms of method. The information used was collected through documentary and library methods and then, according to experts, the indicators affecting the sustainability of the city were identified. Hierarchical analysis (AHP) method has been used to measure the weight of the criteria. In this study, identification of fault lines and their distances from the urban area, long-term seismological studies of seismic centers of the region, seismic hazard zoning map, combination of this map with worn and unofficial tissue map and final map output through fuzzy logic in ARC GIS to assess seismic risk. According to the final map, the seismic hazard assessment in Bojnourd city it seems that the central core of the city and part of the south of the city exposing with quite high risk which is about 40%. Marginal area of the city is exposing with high risk which is about 35%. Rural areas surrounding the city are exposing with medium and low level of risk which is 5.11%. Therefore, it can be concluded that 75% of the land uses and populations in Bojnourd city are exposing with high and quite high level of earthquake risks.