Enhancement of the Web-Based Wildfire Simulator for Wind Intensity Model and Crown Fire Modeling ^†

Abstract

This presentation will provide an overview of some of the recent improvements of the Sardinian Web-based Wildfire Simulator (WWS), a wildfire simulator developed to provide real-time support for wildfire management. We added a midflame wind velocity model integrated within the mass-consistent downscaling wind field module to provide high-resolution wind field maps affected by the vegetation characteristics. This is a generalization of the commonly used wind adjustment factor calculation, suitable for an improved parametrization of the wind calibration framework. The wind adjustment factor adjusts 10 m wind velocity to midflame wind, which affects the surface fire. The model includes a different algorithm for wind above surface fuel that is unsheltered by overstory and wind that is sheltered by forest canopy. In addition, a crown fire spread model was integrated within WWS to predict the onset of crowning, the type of crown fire (i.e., passive or active), and the associated rate of spread and fireline intensity. Crown fires are carried through the crowns of living forests and they are even less common than the surface fire; their impact is severe in terms of fire behavior and fire attack opportunities. We present the preliminary results of a validation of the new codes on a set of actual wildfires that recently occurred in the island of Sardinia, Italy.