- Author
- Cheney, P. | Gould, J. | McCaw, L.
- Title
- Project Vesta: The Prediction of High Intensity Fire Behaviour in Dry Eucaypt Forest.
- Coporate
- Commonwealth Scientific and Industrial Research Organization, Melbourne, Australia Department of Conservation and Land Management, WA
- Report
- Project Vesta, July 6, 2000, 8 p.
- Distribution
- For more information contact: Website: http://www.ffp.csiro.au/vesta/index.html
- Keywords
- forest fires | forestry | fire behavior | fire spread | controlled burning | fuel load | management systems
- Identifiers
- project aims; experimental plan; benefits of the project
- Abstract
- The two fire behaviour systems for predicting fire spread in Australian eucalypt forests today are the "McArthur Forest Fire Danger Rating System" and the "Western Australian Forest Fire Behaviour Tables". Both systems are based on data from an extensive series of short-duration, low-intensity experimental fires lit under a wide range of mild weather conditions and allowed to burn for up to an hour. These systems are excellent for predicting the behaviour of low intensity fires and have been used extensively for operational prescribed burning. They have been extrapolated to predict the behaviour of wildfires burning under more severe conditions in eucalypt forests by adding data and observations gathered from a small number of well-documented wildfires. Although these system have been widely accepted to rate forest fire danger across the country they have been found to inadequately describe the behaviour of moderate-to high-intensity wildfires. Both systems under-predict the rate of spread of high-intensity fires by a factor of 3 or more. These errors have been noted in the past but have been attributed to insufficient estimates of the fine fuel load or spotting ahead of the main fire. It is now apparent that the functional relationships describing the change of rate of spread with increasing wind speed and changing fuel characteristics are both in urgent need of revision. Hazard reduction by prescribed burning is widely used in Australia to reduce the intensity and spread of wildfires. While the effectiveness of fuel reduction is obvious soon after burning there is considerable debate as to how long these benefits persist as fuels re-accumulate, particularly under severe weather conditions conducive to the spread of wildfires. Better information is required to establish critical fuel levels and to establish fuel types where prescribed burning is most effective.