Earthquake Damage Assessment Using SAR Imagery, Structural Data, and Geospatial Parameters

Earthquakes inflict extensive damage on urban settlements, posing significant risks to human life and infrastructure. This study investigates the destruction caused by the Mw=6.7 Sivrice earthquake, which struck on January 24, 2020. It focuses on its impact within the city center via remote sensing (RS) and geographic information system (GIS) methodologies for damage assessment. In the study, post-earthquake building damage data and building inventory, collected through field surveys and provided by the Ministry, were compared with the collapsed areas which were identified using Sentinel-2 optical imagery. The surface velocity rates of the study area over the past five years have been derived using advanced InSAR techniques, specifically Persistent Scatterer (PS) and Small Baseline Subset (SBAS) methods. Moreover, a comprehensive analysis of factors influencing building damage was conducted by integrating geological maps, active fault maps, Coulomb stress distribution, Vs30 velocities, and surface velocity rates in the city center with the building inventory. It was revealed that the damage estimation map produced by analyzing pre-earthquake data and the damage map produced by field studies carried out after the earthquake showed a similar pattern. The findings demonstrate that buildings constructed on alluvial soils having low Vs30 velocities with high surface velocity rates experienced the most severe damage. This analysis highlights critical geological and structural parameters that exacerbate earthquake-induced structural damage, offering valuable insights for urban planning and seismic risk mitigation.