Description

To provide critical spotting information to fire managers and the developers of operational wildfire behavior models, a physics-based spotting model will be developed and used to characterize potential spotting hazard in complex wildland urban interface (WUI) fires. The spread of large-scale fires is a result of two types of phenomena contiguous spread and spotting. Spotting is the phenomenon by which burning material, called firebrands, are lofted by the plume, transported via the fire-influenced wind field, and deposited to ignite new fires ahead of the contiguous fire front. Spotting behavior depends on the strong coupling between fire, atmosphere, topography, and fuels and is therefore difficult to characterize without adequate methods of accounting for this coupling. Predictions of spotting can be achieved by integrating physical firebrand models into HIGRAD/FIRETEC, a premier physics-based model for the prediction of contiguous fire spread. As a preliminary research project, firebrand transport in simple wildfire scenarios was studied using physical models as a post processor of HIGRAD/FIRETEC. Incorporating the firebrand model into HIGRAD/FIRETEC will provide a mechanism to predict spotting locations in a wide range of conditions including rugged terrain, gusty winds, and non-homogeneous fuels. The coupled effects of fuel types/conditions fuel heterogeneity, atmospheric wind speed/gust/turbulence, topography, and human-made structures will be studied through the HIGRAD/FIRETEC_SPOT model and be characterized. The knowledge obtained from this work will be practical information for fire and land management personnel. The proposed work will significantly increase our ability to assess risk, develop mitigation safety strategies, and manage fuels in the WUI.