HIE research finds record fuel dryness was dominant driver of 2019-20 bushfires

Many of the 76 recommendations coming out of the Bushfire Inquiry were based on analyses undertaken by the NSW Bushfire Risk Management Research Hub, of which HIE is a founding member and contributor.

A team of HIE researchers led by Associate Professor Matthias Boer of North Richmond, along with researchers from University of Wollongong, University of NSW and University of Tasmania, found that record fuel dryness was the dominant driver of the fires rather than fuel loads, which were not found to be excessive.

"Our research group, which includes Drs. Rachael Nolan, Hamish Clarke and Anne Griebel, builds models to predict how much fuel there is and how dry that fuel is," Assoc Prof Boer told the Gazette, adding that fieldwork, analysis of satellite imagery and computer models were involved in making those predictions.

"We found that fuel loads in forests and woodlands were not higher than previous years. What was extreme was the widespread dryness of the bush."

Now, the team - in partnership with The Australian National University - is starting a new project funded by the Australian Research Council, NSW Rural Fire Service and the ACT Parks and Conservation Service, to develop a capability to forecast changes in fuel dryness in response to weather and moisture in the soil.

The system is designed to give government agencies more accurate information with more lead time to manage active fires, but also to support decision-making around hazard reduction burning.

"We'll be using these models to forecast where in the landscape fuel is likely to dry out below critical thresholds; if it's wetter than a certain percentage it is unlikely to burn. Knowing where and when forest fuels become available to burn is critical to managing resources," Assoc Prof Boer said.

The NSW Bushfire Risk Management Research Hub also looks at the effectiveness of hazard reduction burns, how long the effects last and how much that depends on local environmental conditions and climate.

"Changing the fuel load is one of the few ways we can interfere with the [fire] system," Assoc Prof Boer said.

"But how much risk reduction do you achieve [by hazard reduction burning]? And what are the costs in terms of the effects on regional air quality or fire-sensitive species? Part of this research has also been picked-up by the inquiry.

"There's a sweet spot in hazard reduction burning; figuring out how much, where and when to burn for optimal effect is critical for the safety of our communities and the conservation of our unique natural heritage"

Assoc Prof Boer is hoping to set-up a course on bushfire science and management for students studying environmental science at WSU's Hawkesbury campus.

The course would provide students with a knowledge and skills base to enter careers in bushfire management, including at government agencies and in consulting.

"There are no courses in the Sydney region like that at the moment," Assoc Prof Boer said.