Prescribed burn-offs have little impact on reducing the extent and intensity of bushfires, a study in Tasmania has found ( http://www.publish.csiro.au/wf/WF17061 ).
Burn-offs are a routine part of preparations for bushfire season, but modelling suggests fire authorities need to target unrealistic amounts of land to have any meaningful effect on taming future wildfires.
The aim of prescribed burning is to reduces the amount of combustible material in the bush so that if a fire starts it won’t spread as far or be as intense.
To test how much prescribed burning would be needed to reduce the intensity and extent of a future bushfire, researchers from the University of Tasmania’s school of biological sciences simulated more than 11,000 fires on a typically dangerous fire-weather day in the apple isle.
They found that firefighters would need to carry out prescribed burn-offs across 31% of Tasmania in order to have a significant impact on reducing the threat from wildfires.
More realistic smaller-scale burn-offs, however, had almost no effect on the extent and intensity of a wildfire.
Professor David Bowman, who helped lead the study, said the findings suggested that planned burn-offs were still necessary but not sufficient.
He said governments and fire authorities needed to consider taking a more local approach, and introduce on the outskirts of towns and cities clever landscape designs that included irrigation and green fire breaks in the form of parklands, that could work in conjunction with burn-offs to help mitigate bushfire risks …
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Guardian
