Spring to bring fire and flood risk to Victoria, and a new warning system
30 August 2022
Published by: https://www.watoday.com.au
AUSTRALIA – Victoria is at risk of both fire and flood this spring because of an unusual weather pattern that has emergency crews on edge and has not been experienced in the past five years.
Emergency services have urged Victorians to stay alert for the dual risks in the lead-up to summer as they roll out a new national fire danger warning later this week.
Whereas the old warning system listed six categories of danger, the new one has four: moderate, high, extreme and catastrophic.
The Bureau of Meteorology predicts warmer-than-average sea surface temperatures paired with a negative Indian Ocean Dipole and a La Nina eventcould lead to a damper than average spring.
The last time Victoria experienced a similar combination of weather conditions was in 2016 and 2017 when widespread flooding cut off towns and caused extensive damage.
Most river catchments, particularly in the eastern and southern parts of the state, are already saturated, which means an unusually wet spring could lead to flooding.
A number of dams and lakes are also near capacity, further restricting the ability of authorities to prevent surges. As of Tuesday, Dartmouth Dam, in the state’s north-east, was at 99 per cent capacity, while Lake Glenmaggie, in Gippsland, was at 91 per cent.
Country Fire Authority chief officer Jason Heffernan said the wet weather might delay the start of bushfire season but warned people against becoming complacent, noting grass fires would be a threat, particularly in the state’s west through the harvest and grain belt areas.
He said it was possible the state’s west would be battling fires at the same time towns in the east fought flooding.
“You need to prepare for fires, but you also need to prepare for floods and storm events,” he said. “It won’t be uncommon, I would suspect, throughout this high-risk weather season to see fires burning in some parts of the state, and floods occurring in others.”
The new, simplified fire danger rating system was devised using improved scientific knowledge on fuel types and weather conditions, and is expected to provide more accurate fire forecasts in summer.
A new fire behaviour index, published by the Bureau of Meteorology, will provide a 100-point scale of potential fire behaviour based on fuel and weather conditions. When the risk is not categorised as either moderate, high, extreme, or catastrophic, a “no rating” basis will apply, meaning no safety action is necessary.
When a category is stipulated, residents in affected areas will need to take the corresponding course of action, from preparing a fire plan during moderate conditions, to acting to protect their life and property when conditions are rated catastrophic.
Unlike the old system, which made its predictions by considering only two fuel types, the new ratings will account for eight different Australian vegetation fuel types: forest, grassland, savanna, spinifex, shrubland, mallee heath, button grass and pine. All vegetation types, except spinifex and button grass, are found in Victoria.
The system will also provide longer-term outlooks for emergency services about what fire behaviour might be like months ahead of time and will be used to inform decisions such as fire bans or burn-offs.
The changes were recommended following the 2019-20 bushfire season. They will come into effect Australia-wide on September 1, providing a single warning system across all states and territories.
Forest Fire Management Victoria chief fire officer Chris Hardman said, as one of the most bushfire-prone areas in the world, Victoria would benefit from the new system.
“It provides government and industry with better decision-making tools and builds a truly national system,” Hardman said. “Fires do not respect boundaries. The establishment of this national system will make a really significant improvement to how we communicate what the particular risks are at any given time to the community.”
Heffernan said social research nationwide showed the old system was confusing for people, who “didn’t quite know how to connect the fire danger rating to what action they should be taking on the ground”.
He said the new system came with a clear call to action, so the community would know what to do, not only during an emergency but also to prepare in the lead-up to bushfire season.
The old signs will be gradually replaced leading into summer, starting in the most bushfire-prone areas.
