Investigation of Seismic Site Characterization and Post-Disaster Urbanization Behavior of Van Province

Abstract

Earthquakes can cause serious damage in residential areas. Thus, various engineering disciplines investigate the causes of this damage and develop new methods based on findings. Furthermore, engineering calculations are of vital importance in urban planning. In this context, this study characterizes the seismicity of Van province through Gutenberg–Richter a- and b-values derived from a two-decade earthquake catalogue (2005–2026). It then maps liquefaction potentials, bearing capacity values, and soil classifications for the study area covering the central districts of Van province, using data obtained from micro-zoning research reports of Van province. The results obtained were mapped using geographic information systems, and the performance of the interpolated surfaces was assessed by leave-one-out cross-validation. The spatial findings were compared with pre- and post-earthquake satellite imagery, and changes in built-up area were quantified for four selected regions to examine post-disaster urbanization. The declustered catalogue yielded a magnitude of completeness of 2.6, a b-value of 1.074 ± 0.065 and an a-value of 5.19 (3.86 on an annual basis), indicating a seismically active region dominated by low-to moderate magnitude events. Low bearing capacity values and liquefaction potential (FS < 1.1) extending to depths of 9 m were identified along the Lake Van shoreline, coinciding with near-surface groundwater and low shear-wave velocities. Reduction in built-up area recorded in the satellite imagery was concentrated within geotechnically unsuitable zones, and reconstruction subsequently occurred within the same areas at comparable or greater densities. These findings highlight the importance of integrating geotechnical analyses into urban-planning and post-disaster reconstruction decisions.