Reliable and accurate models of the speed a wildfire front are essential for providing timely prediction of its propagation across the landscape, to devise suitable suppression strategies to contain it and enable preparation and timely release of effective public warnings. For fires burning in eucalypt forests, fire behaviour analysts in Australia have relied on three basic fire spread rate models for predicting wildfire propagation over the full range of burning conditions: the Control Burning in Eucalypt Forest guide (McArthur 1962), the McArthur Mk 5 Forest Fire Danger Meter (McArthur 1967) and the Project Vesta Dry Eucalypt Forest Fire Model (Cheney et al. 2012).
The new Vesta Mk 2 fire spread model for predicting wildfire rate of forward spread in eucalypt forest (Cruz et al. 2022) was designed to build upon the strengths and advantages of the previous models and also address their operational limitations. The new model utilises existing, easy-to-obtain inputs, and has applicability over a broad range of eucalypt forest types and burning conditions.
Vesta Mk 2 is a multi-phase fire spread model that considers the different fire propagation mechanisms influenced by the involvement of different fuel complex layers in the combustion processes: slow moving, low intensity fires consuming only surface and near-surface fuels; moderate to high intensity fires involving understorey fuels in combustion; and high intensity, fast moving fires involving the full fuel complex. Transitions between these different phases of combustion are linked by the likelihood of occurrence of each propagation phase. The modular structure of the Vesta Mk 2 model enables subsequent independent improvement to be made to any of its components.
The Vesta Mk 2 fire spread model is intended for the operational prediction of wildfire propagation in eucalypt forests over a broad range of fireline intensities. A detailed user’s guide has been developed that provides details on the use and application of the model in an operational fire spread prediction setting. This user’s guide is available for free download to anyone interested in understanding and predicting the behaviour and spread of fires in eucalypt forests. The guide provides a manual method for conducting spread predictions of fires in eucalypt forest as well as equations for incorporation into automated fire spread prediction systems.
The Vesta Mk 2 model has been implemented in version 0.7 of the Amicus computerised bushfire knowledge base and decision support system. This version implements Vesta Mk 2 for both dry and wet eucalypt forests. The new model has also been coded for implementation into the Spark wildfire spread simulation framework.
Cruz MG, Cheney NP, Gould JS, McCaw WL, Kilinc M, Sullivan AL (2022) An empirical-based model for predicting the forward spread rate of wildfires in eucalypt forests. International Journal of Wildland Fire 31. doi:10.1071/WF21068. Online early. Available as open access free download.