Project Vesta has been Australia's most extensive research exercise into intense bushfires in dry eucalypt forests. The 10-year study found that our existing systems for anticipating fire behaviour could under-predict the spread of high-intensity summer fires by a factor of three or more, particularly in severe burning conditions such as those in the infamous 1983 Ash Wednesday fires. The implications of that are obvious.
The research has resulted in a new bushfire spread model for summer wildfires that underpins a national fire behaviour prediction system for dry eucalypt forests. It has also led to critical safety knowledge of the Dead Man Zone for firefighters internationally, and a quick reference field guide for national fire managers that relates fire spread to fuel structure and weather conditions across the entire country.
Mr Rick Sneeuwjagt, State Manager of Fire Management Services for the Western Australia Department of Environment and Conservation, the world's biggest fire jurisdiction, says Project Vesta has given agencies an updated understanding of fire behaviour. 'Knowledge of fire behaviour is totally critical for good fire management and fire suppression; he says. 'We should now be able to predict better how a fire will behave and then, at the beginning of each day, we can organise our resources with much more confidence and accuracy.'
The project has also provided answers on the risks posed by fuel in forests, and the issue of prescribed burning, by analysing the relationship between fire behaviour and fuel age and structure. Mr Jim Gould, CSIRO Bush fire Research Leader, says, 'In the past we have always concentrated on the fuel load but this research has found that the structure and dynamics of fuel are also important to manage'.
Previous fire behaviour guides have been specific to certain vegetation types but the new field guide developed from Project Vesta numerically characterises the different fuel layers in the dry eucalypt forest: surface leaves, twigs and bark; near-surface grasses, low shrubs and suspended dead fine matter; elevated fuel contributed by tall shrubs; and bark on the intermediate and overstorey trees.
'The field guide is a new way of looking at fuel, based on things you can see,' Mr Gould says. 'People can go through it and make quick assessments on fuel hazards without having to do measurements. It gives practitioners and the general public better guidelines on how to assess the fuel on their properties and mitigate their risks.'
Mr Sneeuwjagt highlighted that the guide is important in that fuel structure can be consistently described among fire managers.
Fire agencies around Australia received copies of the field guide in December 2007, and the Vesta researchers plan to undertake a national roadshow in 2008 to help implement the new assessment system.
The wider study found that prescribed burning will reduce the rate of spread, flame height and intensity of a fire. 'There has been criticism of burning off,' Mr Sneeuwjagt says, 'but now we can confirm its value in hard figures. It's a good tool backed with good science.'
Mr Gould says that while the relevant agencies must manage prescribed burning against other biodiversity issues, burning off has shown to be effective for up to 20 years on some types of fuel structure. 'It will also reduce bark fuel" he says. 'Spotting and ember attack from bark is one of the major causes of loss of houses and property.'
Project Vesta was a major cooperative effort conducted by CSIRO Forest Biosciences and the WA Department of Environment and Conservation (DEC), with support given by a range of agencies including the Australasian Fire Authorities Council (AFAC), Hermon Slade Foundation, Forest and Wood Products Research and Development Corporation, Bushfire CRC, other research …