Landscape dryness information is considered critical for improved risk management and for prescribed burn decision making, so how well do current information products work?
Along with answering this question, researchers from Natural Hazards Research Australia’s (the Centre) Identifying and defining landscape dryness thresholds for fires project are developing ways to map landscape dryness to deliver important operational intelligence before a fire season.
Outcomes of this research will include improved accuracy of fire simulation systems and fire danger rating systems, added value to seasonal forecasting and better interpretation of landscape condition monitoring systems.
The project comprises researchers from The University of Melbourne, Western Sydney University and Natural Resources Canada and is supported by the Country Fire Authority (Victoria), Australian Capital Territory Parks and Conservation Service, Department of Fires and Emergency Services (Western Australia), New South Wales Rural Fire Service and the AFAC Predictive Services Group.
Project research leader Dr Jane Cawson from the University of Melbourne believes landscape dryness is a primary driver of wildfire risk because it indicates how much vegetation – that is, fuel – is available to burn.
“Although many metrics quantify dryness, only a few are routinely used in seasonal outlooks. While there are a range of new metrics available, including remotely sensed soil moisture, it is unclear if they are useful as there has been no comprehensive, nationwide evaluation of the wider set of metrics,” Dr Cawson said.
“Our project is testing a wide range of metrics to see which best predict the severity of a fire season in different regions of Australia. The aim is to define clear, regionally appropriate dryness thresholds that can be incorporated into outlook products so fire agencies and communities get more reliable early warnings and can better prepare for a fire season,” she said.
Dr Cawson said that predicting the severity of upcoming fire seasons is complex, as there are multiple interacting factors with landscape dryness representing a key driver.
Despite this difficulty, she shared that the research team have identified several metrics that perform better than those currently used.
“Two key metrics which show strong potential are remotely sensed soil moisture products and Standardised Precipitation and Evapotranspiration Index, a multi-scalar drought index. Using this information, we can now produce maps of predicted fire season severity at different periods leading up to the fire season – 3, 6, and 9 months prior – providing critical information for fire management,” she said.
Talking to the importance of this research for building resilience and community safety, another project researcher, Dr Jamie Burton from the University of Melbourne, highlighted the reliance of many fire management decisions on knowing how severe an upcoming fire season is likely to be.
“Landscape dryness is central to that assessment. Early in the project we spoke with a range of fire practitioners to hear how they use landscape dryness information. They told us it guides a range of decisions from resourcing: the number and location of aircraft and seasonal crews; declaring the start of a fire danger period; logistics: bringing in extra water; and situational awareness: understanding whether usually wet gullies are at risk of burning,” Dr Burton said.
“Access to reliable dryness products and understanding how they link to fire risk would help inform these decisions,” she said.
Dr Burton said that organisations, such as fire agencies and the Bureau of Meteorology, base their seasonal outlooks on dryness information.
“Our research is about improving the reliability of those seasonal outlooks, using new metrics and testing their effectiveness against historic fire data, so that fire agencies and the broader community can make decisions informed by the most reliable information out there,” she said.
Learn more about the Identifying and defining landscape dryness thresholds for fires project on our website.