Preliminary Landslide Hazard and Multi-Infrastructure Exposure Assessment along the Arifiye-Bozüyük Corridor in Western Türkiye

Critical transport routes in tectonically active regions, such as the Arifiye-Bozüyük corridor in Western Türkiye, are under serious threat due to slope instabilities that are worsened by rugged terrain and complex lithological units. Connecting the Sakarya basin to the Central Anatolian plateau, this region hosts a dense multi-infrastructure network comprising the D-650 Highway (handling over 30,000 vehicles daily), a vital high-speed and conventional railway line, and expanding settlement clusters. Due to the corridor’s proximity to the North Anatolian Fault Zone (NAFZ) and its significance as a primary logistical route, slope failures pose both a local safety risk and a broader threat to national supply chains. A preliminary framework is presented to assess landslide hazard and quantify the exposure of these critical assets. A GIS-based multi-criteria decision analysis was implemented to evaluate landslide hazard by integrating nine causative factors: slope, aspect, curvature, lithology, drainage density, fault density, topographic wetness index (TWI), and distance to road. These parameters were standardized and weighted using the Analytic Hierarchy Process (AHP), with an emphasis on morphological factors and lithological resistance, based on regional expert insights, to capture the specific landslide mechanism in the Arifiye-Bozüyük corridor. The model produced initial hazard zones categorized from low to very high susceptibility. Moving beyond traditional pixel-based susceptibility mapping, the hazard rasters were overlaid with vector-based linear transport networks and building footprints extracted from the Microsoft Planetary Computer open data archive. The object-based approach enabled detailed intersection analysis, distinguishing between overall areal risks and specific infrastructure exposures. The analysis facilitated a comprehensive exposure assessment, pinpointing the spatial distribution of at-risk highway sections, railway segments, and residential structures. An approach that combines AHP-based hazard models with global open-source object data provides a scalable and cost-effective method for initial risk screening. The findings serve as a foundational layer for decision-makers to prioritize detailed field verification, implement early warning systems, and design site-specific geotechnical mitigation measures for the most vulnerable segments.