Risk and Behavior of Fire Spread in A Densely-built Urban Area

A fire staring in a densely-built urban area easily spreads to adjacent buildings. In the case of large earthquakes in which multiple fires may break out simultaneously, the spread of such fires may overwhelm the ability of firefighters and damage large areas. In this study, fire spread simulations were carried out in order to investigate behavior of fire spread in Kyoto Higashiyama area, one of the representatives of densely-built urban areas in Japan. A physics-based model was used in which the following mechanisms of fire spread are considered: thermal radiation heat transfer from fire-involved buildings; elevation of ambient temperature by wind-blown fire plumes; and spotting ignition by firebrands. The risk of fire spread was also analyzed by the Monte Carlo method to evaluate the expected magnitude of loss. The effect of uncertainty of the location of fire origin and the weather conditions was investigated.