Fire science adds to understanding of 2019/20 summer bushfires

Hundreds of people tuned in each week to hear experts and practitioners explain the science surrounding hazard reduction burning as part of the three-part National Fire Fuels Science webinar series.

Set against the backdrop of the devastating 2019/20 bushfire season, of which hazard reduction burning was a contentious issue, the Bushfire and Natural Hazards CRC and the Australian Academy of Science invited leading figures in bushfire science and knowledge to explain what is known, what is unknown and what is in contention. The aim was to lay the foundations of a future national approach to hazard reduction burning and support the inquiries into the fires, such as the Australian Government’s Royal Commission and the various state-based inquiries.

In support of these inquiries, up to 500 people attended the live webinar each week over three successive weeks in May, with hundreds more watching the replays on the CRC’s Hazard Channel.

Each session was hosted by land and fire management expert Gary Morgan, and was followed by an engaging Q&A session between the presenters and audience, moderated by CRC Research Director Dr John Bates. There are now also extended Q&A videos available, with speakers answering questions not covered in the live Q&A.

The first webinar, on Wednesday 6 May, provided an engaging introduction to hazard reduction burning. Dr Sarah Harris (Country Fire Authority) explained meteorological indicators, and the effects of the fire season and climate change on the natural environment. Sascha Rundle (ABC Emergency Broadcasting) highlighted the diverse public perceptions about prescribed burning and explained the need to work with the community on this issue. Oliver Costello (Firesticks Alliance) described the benefits of cultural burning on Country, while Justin Leonard (CSIRO) put forward the factors influencing the impact of fire on buildings and where best to build homes in future.

The second webinar, on Wednesday 13 May, expanded on the content of the first by outlining the science of hazard reduction burning. Dr Neil Burrows (FireNinti Consultancy) explained the importance of scientific, historical and experiential evidence that supports prescribed burning benefits. Prof Mike Clarke (La Trobe University) outlined the relationship between wildfire risk and hazard reduction burning. A/Prof Tina Bell (University of Sydney and CRC researcher) discussed the influence of planned and unplanned burns on carbon and water assets. Dr Phil Zylstra (Curtin University) detailed the nuanced theoretical and practical relationship between fire fuel load and rate of spread. Prof Mark Adams (Swinburne University) finished the discussion by describing some key myths, miscalculations and misunderstandings about fire fuels and how to combat it.

The third and final webinar, on Wednesday 20 May, rounded out the series with a discussion of the potentials and limitations when applying hazard reduction burning. Dr Adam Leavesley (ACT Parks and Conservation Service) gave a practical perspective, referencing the ACT’s Orroral fire in 2020 as an example of the effects of planned burning on bushfire suppression and landscape. Dr Valerie Densmore (WA Department of Biodiversity, Conservation and Attractions) outlined one of the pitfalls and complications of prescribed burning in practice – the effects and changes of fuel moisture differentiation. Ruth Ryan (HVP Plantations) provided a plantation industry perspective, including the need for risk modelling that considers social and cultural implications. Lastly, Dr Simon Heemstra (NSW Rural Fire Service) explained the ways that fire services use science to improve the practice, application and communication of hazard reduction burning.

The series enabled an informative and accessible discussion of the issues, science, constraints, beliefs, culture, truths and myths around hazard reduction burning in Australia.

For those who missed out or would like to refer back to the series, the following is available for each session:

• Replay the webinar recordings and watch the extended Q&A sessions here.
• View the speaker presentations, questions from the audience and background papers from speakers here.

Many of the issues covered in the series are addressed in a recent special edition of the International Journal of Wildland Fire called Adaptive prescribed burning in Australia for the early 21st century – context, status, challenges.

A comprehensive book on hazard reduction burning around Australia is being launched this week through the Centre of Excellence for Prescribed Burning called Prescribed burning in Australasia: the science, practice and politics of burning the bush.

The National Fire Fuels Science webinar series was held as a scaled-down version of a forum that was originally scheduled for late March in Canberra. The Canberra forum was cancelled due to COVID-19.