Australia Bushfires
by googlerecipe.co June 24, 2024 · Science Explore
The Science of Bushfires: How to Control Them and Why They Spread Quicker
Australia Bushfires? In Australia bushfires are very common because the country has a lot of them each year. But do you know how or why they start? Let’s find out by learning what fire is.
Fire needs three things: heat, oxygen, and fuel. Fuel is anything that burns. When these three things come together, they create a chemical reaction called combustion, which produces heat and light—the flame you see.
Fire is self-sustaining
Fire is self-sustaining, meaning it keeps going as long as it has fuel and oxygen. A fire usually starts from a spark. In Australia, bushfires can start from human actions, carelessness, or dry lightning strikes.
Most fires are caused by people. Since Australia is hot and dry with frequent droughts, it makes it easier for things to catch fire. The land here has evolved to handle fires, with wet winters and dry summers making vegetation more likely to burn.
Fire spreads based on the type of vegetation, the weather, and the land’s shape. I spoke with Robbie, a rural firefighting trainer, to explain more.
Fire behavior
Robbie showed me a burn table used to teach about fire behavior. If a lightning strike starts a fire with no wind, it burns in a circular pattern. But wind or a slope can change this. For example, lighting a fire on a slope can make it spread faster.
Fire travels faster up a slope because the heat pushes the fuel in front of it, making the fire move faster. The shape of the fire and how many fires there are also affect its behavior.
When flames lean into each other, it’s called junction zoning. This happens when convection columns join, increasing the fire’s intensity.
Strong winds make bushfires worse by providing more oxygen, which increases the fire’s intensity and makes it spread faster.
Fire thunderstorms, and clouds
In some cases, bushfires can get so powerful that they create their own weather. They can even generate fire thunderstorm clouds, which can start new fires far away. Embers from the fire, like burning leaves and twigs, can also start spot fires miles away.
Radiant heat from a fire can be so intense that it causes nearby fuel to catch fire on its own. This makes fires spread faster and more dangerously.
To manage or prevent bushfires
To manage or prevent bushfires, we sometimes use controlled burns to reduce fuel in the landscape. This technique, called cultural burning, has been practiced by Indigenous Australians for thousands of years. It keeps fires low-intensity to protect plants and animals.
In addition to these methods, you can also help by keeping fuel loads low around your home, avoiding activities that might cause fires, paying attention to weather conditions, and having a bushfire survival plan if you live in a fire-prone area.
Conclusion
Bushfires are a common and serious issue in Australia due to its hot, dry climate and frequent droughts. They start when heat, oxygen, and fuel come together, creating a self-sustaining reaction.
While human activities and dry lightning are major causes, fire behavior is influenced by vegetation, weather, and terrain.
To manage bushfires, controlled burns reduce fuel and maintain the landscape. Indigenous practices of cultural burning help prevent intense fires by keeping them low-intensity.
By understanding how fires work and taking preventive measures, such as maintaining fuel loads and having a survival plan, we can better protect ourselves and our communities from the dangers of bushfires.
The following are some often asked questions (FAQs) concerning bushfires:
What causes bushfires?
Bushfires can start from natural causes like lightning strikes or from human activities, such as carelessness or deliberate arson. In Australia, dry conditions and frequent droughts make fires more likely.
How does a fire spread?
Fire spreads based on the type of vegetation, weather conditions, and the shape of the land. Wind and slopes can accelerate the spread, as heat from the fire pushes through fuel in front of it.
Why does fire spread faster up a slope?
Fire spreads faster up a slope because the heat pushes the fuel in front of the fire upward, making it burn more intensely and spread more quickly.
What is radiant heat?
Radiant heat is the intense heat emitted by a fire that can ignite nearby materials even without direct contact. It can cause surrounding fuel to catch fire on its own.
What are embers?
Embers are burning materials, like leaves and twigs, that can be carried by the wind and start new fires far from the original blaze.
How can bushfires be managed or prevented?
Bushfires can be managed using controlled or prescribed burns to reduce fuel. Indigenous cultural burning practices also help by keeping fires low-intensity. Additionally, maintaining low fuel loads around homes and having a bushfire survival plan can help prevent and manage fires.
What is cultural burning?
Cultural burning is a traditional practice used by Indigenous Australians to manage the landscape. It involves deliberately setting low-intensity fires to reduce fuel and protect the environment.
