On June 16, the Lithgow Mercury ran an article titled 'Science at the Local to have first webinar all about bushfires with expert Hamish Clarke' where we reached out and asked our readers to submit some questions for the scientist.
We received a handful of questions that we then passed on to Hamish, who kindly responded.
Take a look at his answers to your questions below.
1. How do you think a big fire season such as the one we had could be prevented from happening again?
That's a tough question. There are many things we can do to reduce bushfire risk, from prescribed burning and other activities by fire agencies and land managers, to community education and awareness, planning and construction rules and regulations, and householder actions such as preparing your property and having a plan. The big fire season we just had was at least partly influenced by record heat and dryness and climate change could make those extreme conditions occur more frequently.
2. Do you believe slow burning or back burning is a good way to stop the spread of fire?
I think this is a question about containment burning i.e. fires lit during a bushfire in order to help with suppression. Great question. The practice is widely used and no doubt played a vital role in some cases. But containment burns can be risky too. There's a need for more research on how it is used and its effectiveness at mitigating risk.
3. Is back burning the key to less fires?
I think this question is about prescribed burning i.e. fires lit during the shoulder season in order to make subsequent unplanned bushfires easier to suppress. Prescribed burning can definitely help, but it's not a silver bullet. Effectiveness may vary depending on where the burn was done and how severe it was. Its effects don't last forever, and are sometimes overwhelmed by other factors such as extreme weather.
It would be great to understand just how prescribed burning affects risk to a whole range of things, not just people and property but the environment, human health impacts from smoke, etc. I'm involved in research in this area, and there's no one size fits all solution - different places will benefit from different strategies, and there are always trade-offs involved. Another important question is cost-effectiveness - what gives us the best bang for our buck, factoring in all those things we care about?
4. Why do fires spread so fast?
Fire spread is classically considered to be driven by fuel amount and weather (think: hot, dry and windy). There are other important factors like topography (fires can run faster uphill) and fuel moisture (dry fuels will burn more quickly, moist gullies can provide a natural fire break). Grass fires behave quite differently to forest fires and can spread more quickly, although forest fires can spot i.e. send embers and firebrands well ahead of the fire front, starting new fires sometimes tens of kilometres away. There's a range of extreme fire behaviours that can affect fire spread.
5. How can people help stop the spread of fires?
There's lots of things people can do to reduce bushfire risk. A great place to start is the NSW Rural Fire Service website https://www.rfs.nsw.gov.au/ which talks about things like having a plan, preparing your home, and reporting fires.