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What makes a megafire?

Despite spending our summers on high alert for fire danger, the relationship between droughts and heatwaves and how they exacerbate bushfires is still poorly understood. But a cohort of Australian environmental scientists is on a mission to understand these links, to better assist communities in preventing and preparing for bushfires.

How dead fine fuel can intensify a bushfire

We know that droughts and heatwaves lead to reduced moisture content in dead vegetation, which then becomes fuel in bushfire-prone areas. However, while the dryness of dead fine fuel can be affected by the intensity and duration of a heatwave, new research by a team of Australian environmental scientists published on ScienceDirect shows that the effects differ across regions.

For example, in the ACT, the duration of a heatwave led to lower moisture content in the fuel. While in northeastern NSW, southeastern QLD and central Victoria, the intensity of a heatwave had the biggest effect on the fuel moisture content.

Of course, drought only makes things worse. It intensifies the effect of a heatwave and can lead to critically low fuel moisture. So, a longer heatwave in the ACT, coupled with drought, creates the driest fuel. And in central Victoria, extreme temperatures mixed with a drought, leads to the lowest moisture content.

By understanding how drought and heatwaves affect different regions, we can be better prepared and more accurately assess the fire danger. It may also help predict the risk of catastrophic fires and where they’re likely to occur.

The risk of a ‘megafire’

Researchers found that drier fuel can increase the risk of a megafire, an extremely large fire that can burn for months on end and takes more resources to extinguish.

Megafires also consist of multiple extreme fires. These are intense fires in smaller areas that only burn for a few hours, but they can do immense damage. They also have the ability to create their own weather and can even turn into deadly fire thunderstorms.

And what’s one of the main causes of these extreme fires? You guessed it - low moisture content in the dead vegetation that becomes a fire’s fuel. Thanks to the work of these climate researchers, we now have a better understanding of low moisture content in bushfire fuel and the weather events that create these drier fuels. What this means is the opportunity to develop more effective strategies for clearing and burning-off in the cooler months. For environmental scientists, it’s more thorough information to help predict and, hopefully, prevent the formation of megafires in the future.

Insuring for disaster

If your property is in an area that’s at risk of bushfire, consider chatting to your local WFI area manager.

For more information on bushfires, check out this fact sheet.   

To see if a product is right for you, always consider the Product Disclosure Statement available from the product issuer, Insurance Australia Limited ABN 11 000 016 722 trading as WFI.