Understanding fuel types is critical for the improved control of bushfires. Initial work for this project focused on revising and improving a fuel classification system developed by David Sandberg and colleagues in the United States. This is a universal classification and hierarchical in structure, with the advantage of providing the necessary parameters for fire behaviour, smoke emission, ecological and other possible models regardless of the amount of detail known about fuels at any particular point in the landscape. This work is being carried out in collaboration with the USDA Forest Service. Results to date have been to add bark fuels, unshed branches in plantations, and near-surface fuels to the classification.

The classification system was applied to the fuels in the Tumbarumba experiment in February 2004. Systematic classification of fuels across Australia and the development of the classification hierarchy is the next challenge. The project’s second component relates to fuel consumption. This research aims to be able to predict the extent of fuel consumption under different fire, fuel and weather conditions so that fire behaviour and smoke emission models can be improved. Initial research was undertaken in Tumbarumba, NSW, in February 2004, when a methodology was developed and initial results obtained. The high level of fuel moisture variability in coarse woody debris in natural forests is a significant problem for fuel consumption modelling. A significant difference in fuel moisture was found between woody material in contact with the ground and material suspended above it, suggesting that the modelling of fuel moisture and availability in natural forests is likely to be more complex than has been indicated by previously published research (predominantly relating to recently logged forest).

The outcomes of this project will include the development of a universal classification of fuel types and extent of fuel consumption in bushfire behaviour, for the better management of bushfires.