Direction houses face influences fire risk
Construction and proximity to forest increase danger
Climate change will intensify bushfires
Scientists have worked out what houses are likely to survive a bushfire after analysing 85 risk factors to determine whether a home is expected to be incinerated or not.
Two fires in the NSW Blue Mountains which destroyed 200 houses in October 2013, were examined by University of Wollongong researchers and published in the journal Fire.
While weather and proximity to native forest were two key issues that influenced if a house was destroyed or not, the study also concluded that proximity to other burnt houses, construction materials, and whether the property was defended or not were also crucial.
Another surprising factor was which direction the house faced, the study’s lead author Professor Owen Price from the Centre for Environmental Risk Management of Bushfire found.
“We found that the worst-placed houses are western-facing, without defensible space (where landscaping, plants or other things that fuel fires are set away from the building) and have other burnt houses nearby,” he said.
“These properties are 10 times more likely to be impacted in a fire.”
“Additionally, plants growing over the house and the presence of lawns and artificial fuels such as fences can influence a house destruction.”
Six key reasons homes are impacted by fire
Topography and direction of house
Defensible space (proximity to plants and fuels)
If nearby houses are burnt
Whether the house is defended
Closeness to native forest
Why west-facing houses can be prone to bushfires
Because the 2013 Blue Mountains fires were moving in a westerly direction, it was westerly facing houses that suffered greater devastation, however Professor Price believes the believes the research has wider ramifications.
“It turns out that many of the really bad fires occur on westerly, northwesterly winds,” he said.
When these winds drive the flames up hills, where the majority of fires occur, the fire’s behaviour will increase on the upslope.
“When a fire is burning up a hill, the fire is closer to the ground and therefore closer fuel, and everything gets heated quicker,” Professor Price said.
“If you’re on the upslope facing the fire you’re in a worse situation than if you were on the slope facing away from the fire.”
Professor Price said much of the information disseminated in his study was already known by firefighters, however being able to now back it up with scientific evidence will help create confidence in decision making.
This will become more important as fires continue to become more extreme across the world due to climate change.
“They can say look, people done research, and they've confirmed this,” he said.
Do you have a story tip? Email: email@example.com