Development of a Fire Spread Model for Post-Earthquake Fire Risk Assessment in Areas with Insufficient Fire-Related Data

Abstract

Post-earthquake fire, also referred to as fire following earthquake (FFE), can cause severe urban damage, particularly where detailed empirical fire-spread records are unavailable. This study derives a simulation-informed regional regression relationship between covering volume fraction (CVF) and fire-burned ratio for screening-level assessment in Pohang, South Korea, and integrates it into an existing static FFE risk-assessment framework. A total of 6604 dynamic fire-spread simulations were generated by varying the composition and assignment of four fire-resistance categories within the fixed GIS geometry of Region H. Building spacing, street form, wind direction, wind speed, relative humidity, and fire-spread duration were not independently varied; all calibration simulations used an NNW wind direction, a wind speed of 6.4 m/s, a relative humidity of 40%, and a fire-spread duration of 3 h. For the matched benchmark zones A, H, and J, the proposed relationship yielded relative differences of 0.21%, 19.31%, and 6.35%, respectively, relative to the TFD-based benchmark simulations. These comparisons are reported as simulation-informed matched-zone benchmarking within the same modeling framework and should not be interpreted as independent real-event or cross-city validation. From a sustainability perspective, the framework can support disaster-risk-informed urban planning by prioritizing districts for detailed analysis and mitigation, although environmental, social, and economic benefits were not quantified directly.