Researchers conclude that houses need to be much further away from the forest than the official recommendation

This article is more than 7 years old

This article is more than 7 years old

A study of Victoria's Black Saturday bushfires has found the risk zone between houses and forests is much wider than authorities say.

Houses up to one kilometre from large forest areas are at risk from bushfires, according to research from the University of Wollongong.

The finding is at odds with Australian fire management authorities, who state that the risk zone is between 25 metres and 500 metres, varying from state to state.

The results have prompted the researchers to call on authorities to revise their risk management recommendations.

"The zone of one kilometre around houses is very large and requires a rethink of bushfire risk strategies," study co-author Dr Owen Price said.

The study looked at the 2009 Victorian bushfires, the worst in Australia's history, which claimed 173 lives and caused more than $4bn worth of damage.

Using statistical modelling, a sample of 3500 houses affected in the fires was studied, looking at how the amount of forest around houses affected the likelihood of them being destroyed. Researchers found that houses surrounded by a large area of forest were still at risk if the trees were within one kilometre of the house. Homes were also more likely to be destroyed if there were other houses within 50 metres and if they were on a slope.

Dr Price said previous studies had already shown that hazard reduction burns were of little benefit in catastrophic fire conditions. He said residents who were surrounded by forest should rather look at fireproofing their homes.

"Because the main threats seem to be from embers and house-to-house transmission, hardening houses to fire is another obvious way that risk could be reduced," he said.

Risk strategies should also be revised to include wider setbacks between new developments and forests, he said.

The study results are published in scientific journal PLOS ONE.