Earthquake Risk Analysis in a Medium-Scale Settlement Area Using Empirical Attenuation Models: The Saraydüzü Example

Türkiye is a country at high seismic risk due to its location on active tectonic zones. Therefore, regional-scale studies to reduce earthquake risk are of great importance. In this study, the soil-geotechnical properties, existing building stock, settlement patterns, and historical earthquake records of the Saraydüzü district of Sinop province, located close to the North Anatolian Fault Zone, were examined in detail. Seismic hazard assessment, Vs(30)-based soil classification, building inventory analysis, and earthquake scenario modeling were performed during the analysis. ELER v3.0 software was used in scenario development, and the Erdik and Eren (1983) model was applied as an empirical attenuation relation specific to Turkish conditions. In the scenario developed based on the February 6, 2023, Kahramanmaraş-centered earthquake, calculations based on 14588 residences projected to suffer severe or collapsed damage indicate that approximately 1508 people could lose their lives, with a loss of life rate of approximately 10335 for every 100 structures. Using an injury/death ratio of 2.019 for the same earthquake, it was estimated that approximately 3044 people could be injured. Multiplying the total of 17197 moderately and severely damaged residences by the 2024 average household size of 2.61 people in Turkey and subtracting the number of deaths, it was determined that approximately 43377 people would be in need of shelter. In the second scenario, using the parameters of the August 17, 1999 Izmit Gulf Earthquake, the number of residences with severe/collapsed damage was calculated as 322. Applying a 26% loss of life ratio, it was estimated that approximately 84 people could lose their lives. Similarly, using an injury/death ratio of 2.515, it was determined that 211 people could be injured, and based on household size, approximately 3155 people would need shelter. The results demonstrate that medium-sized settlements can be as high a seismic risk as large cities, clearly demonstrating the importance of disaster preparedness in such regions. It is evaluated that these analyses, specifically conducted in Saraydüzü, will be instructive for other settlement areas with similar characteristics and will contribute to Türkiye's earthquake response processes at a local scale.