Recalibrating fire warning science

As Western Australia and the rest of the world prepare for a hotter, drier climate in the years and decades ahead, Murdoch University researchers are working to determine which areas of the state may be at a greater risk of bushfires.

The current fire weather warning system is based on the McArthur Forest Fire Danger Index, which operates as an algorithm using inputs of wind speed, temperature, rainfall and relative humidity to determine the degree of fire danger from low/moderate (0-11) through to extreme (75-99) and catastrophic (100+).

Murdoch honours student Alyce Sala-Tenna told Business News her research was aimed at determining how these degrees of fire danger might change over time, by working with PhD student Julia Andrys, who has simulated climate data over the state’s South West to provide climate projections up to the year 2059.

“For example, if the annual average is of the FFDI is 50 in 1990 at a particular location and the annual average in 2020 is 70 at the same location, that indicates a change and thus higher risk,” Ms Alyce Sala-Tenna said.

While investigations into the recent bushfires in the South West, in particular the tragic loss of two lives and the town of Yarloop, have delved into what warnings were given and the amount of time the community had to prepare, Murdoch University’s research is aimed at longer-term strategic planning.

The team’s data-intensive work requires the enormous capability of the Pawsey Supercomputing Centre, with outputs potentially being able to indicate shifts in fire weather’s intensity, frequency, and occurrence in the decades to come.
Ms Sala-Tenna said if WA could better project future weather changes, communities could be more prepared.

“We will be able to say how a change in climate, predominantly a rise in temperature and a decline in rainfall, may affect fire weather in the future,” she said. “But first we have to establish if the models can actually project the Forest Fire Danger Index efficiently.

“It’s pointless to use results that aren’t accurate, and implement the findings to do a prescribed burning plan, because it might not be correcting seasonal timing.”