The NSW Bushfire Risk Management Research Hub webinar series presents the research projects undertaken by the Hub to assist the NSW Bushfire Inquiry, 2020. The Hub supported the inquiry by providing analysis, technical and scientific advice and recommendations to ensure the inquiry has actionable, evidence based and rigorous information.
The second webinar of the series is Fire severity, fire spread and lessons learned from the 2019-2020 fire season.
In this seminar we present an analysis of patterns of fire severity and fire behaviour for the 2019-2020 fire season. This fire season was exceptional for its length, running uninterrupted for many months, with the first recorded fire on the 9th of August, and ending on March 2nd, burning 5.5 million hectares in NSW in total. Extreme and catastrophic fire weather was associated with periods of major fire spread, although the largest fire, Gospers Mountain, spread under more moderate conditions.
Not all fire has the same ecological impact; “severity” is the measure of the impact of fire in terms of layers of vegetation burnt and canopy loss. Satellite measurements are increasingly able to provide fine-scale measures of severity over broad areas, and this seminar will discuss the FESM algorithm used to map severity across the state for both this season, and previous seasons. We will discuss the drivers of patterns of severity across three case-study fires; Bees Nest, Gospers Mountain and the South Coast complex. Past fire was found to have some impact in reducing severity, although this effect was reduced for previously hazard reduction burnt areas under severe fire weather conditions. It is clear landscape burning can have some impact in reducing severity and slowing fire spread, but this effect is not consistent and can be relatively short-lived.
Presenters: Associate Professor Owen Price (University of Wollongong), Dr Rebecca Gibson (Department of Planning, Industry and Environment) and Dr Grant Williamson (University of Tasmania)