Geographical Process
Bushfires are caused by long periods of dry and hot weather, which causes vegetation to burn easily. There are 2 general causes of bushfires;
The only natural cause are lighting strikes, making up 26% of bush fire causes.
Sadly, this means that the majority of bushfires are caused by humans. Unattended campfires and burning vegetation make up 26%, and cigarettes and sparking machinery make up 10%. Even more disturbingly, 25% of bush fires are caused deliberately, by arsonists. Therefore, there are severe penalties in place for the misuse of fire, and arson in general.
The effects of bushfires have resulted in many animals and plants adapting in order to survive, native plants in particular. Plants have adapted by having thick bark and protected shoots and tissue so it can regenerate after a fire.
Different types of animals have ways of surviving bush fires:
- Naturally
- Human influence
The only natural cause are lighting strikes, making up 26% of bush fire causes.
Sadly, this means that the majority of bushfires are caused by humans. Unattended campfires and burning vegetation make up 26%, and cigarettes and sparking machinery make up 10%. Even more disturbingly, 25% of bush fires are caused deliberately, by arsonists. Therefore, there are severe penalties in place for the misuse of fire, and arson in general.
The effects of bushfires have resulted in many animals and plants adapting in order to survive, native plants in particular. Plants have adapted by having thick bark and protected shoots and tissue so it can regenerate after a fire.
Different types of animals have ways of surviving bush fires:
- Fast moving animals like birds, kangaroos and wallabies can simply run away from the fire.
- Echidnas and wombats can escape by hiding in logs or burrows.
- Reptiles, amphibians and other underground animals can hide underground or in water.
- Possums and other arboreal mammals can climb to the crowns of trees to escape.
Fires need 3 key factors in place in order to grow and spread- fuel, oxygen and heat. These factors form the fire triangle. The fire can only be extinguished when one of those factors are eliminated.
- Fuel- good fuel sources are grasslands and dry sclerophyll forests. eucalyptus trees are constantly shedding their leaves throughout the year and their oil helps fires spread quickly under the right conditions.
- Oxygen- the oxygen is stimulated by strong winds (which are caused by steep pressure gradients occurring between high and low pressure systems). This typically occurs over south-east Australia in spring and summer. The fire front will move in the direction the wind blows. A change in that wind direction causes a bigger fire front as the wind blows across the fire flank. Dry winds from the middle of Australia bring the hot and dry conditions with it. All of this adds to the intensity of the fire. Simple wind changes can turn small fires into massive fire fronts.
- Heat- the sun and high temperatures dry out the fuel sources, making them more vulnerable to flames and easier to ignite. The typical Australian summer of hot and dry days also adds to the risk.
The 2 main fuel types for bushfires are eucalyptus leaves and grass. Rough barked trees burn more easily than smooth barked trees, and the flames spread from the ground up.
Once bushfires spread into urban areas, it causes damage to the environment, stunts the economy and causes social distress. The intensity of the fire dictates the severity of the effects.
When bush fires are ignited, there are 4 environmental factors that determine the fires course:
Despite this, bushfires are essential to the Australian environment. Our ecosystems have evolved with fire and the landscape and biological diversity has been shaped by it. Many native Australian plants are prone to fire and others require it to reproduce.
The indigenous Aborigines have used fire as a tool for managing the land, and is used to clear the land for regrowth. Firefighters now use this method, called back burning, to help protect houses and other buildings from bushfires. Back burning is the process of burning away undergrowth in fire prone areas to prevent bushfires from being able to spread there.
Once bushfires spread into urban areas, it causes damage to the environment, stunts the economy and causes social distress. The intensity of the fire dictates the severity of the effects.
When bush fires are ignited, there are 4 environmental factors that determine the fires course:
- Amount of rainfall- the less moisture there is, the worse the fire will be.
- Wind- the stronger it is, the faster and further the flames will spread.
- Humidity- you generally don't want it to drop below 20%
- Temperature- cool temperatures are ideal when battling the flames.
Despite this, bushfires are essential to the Australian environment. Our ecosystems have evolved with fire and the landscape and biological diversity has been shaped by it. Many native Australian plants are prone to fire and others require it to reproduce.
The indigenous Aborigines have used fire as a tool for managing the land, and is used to clear the land for regrowth. Firefighters now use this method, called back burning, to help protect houses and other buildings from bushfires. Back burning is the process of burning away undergrowth in fire prone areas to prevent bushfires from being able to spread there.