Influence of topography on firebrand transport

In forest fires, spot ignition by firebrands is one of the major fire spread mechanisms. Since the firebrands are lifted and transported by the fire-induced winds, the influence of topography on these winds has a critical impact on firebrand transport. Using a coupled atmosphere/fire wildfire behavior model, HIGRAD/FIRETEC, the influence of topography on transport of firebrand has been studied for forest fires. Cylindrical firebrand models with combustion, which represent firebrands from forest fires, are used for this study. Wildfires scenarios with both idealized topography and real topography are considered for the study. The topographic effects on spotting behavior includes effectiveness and manner of firebrand launching and travel distance. Preliminary results show that the position of fires with respect to topographic features plays a critical role in the impact of spotting.