During most summers, Australia will experience a significant bushfire event that can devastate lives, forests and impact on the suburban fringes of major cities.
During most summers, Australia will experience a significant bushfire event that can devastate lives, the environment and impact on the suburban fringes of major cities.
Unlike the common practice of back burning, wildfires or bushfires are fires that are unmanaged and burn uncontrollably. A bushfire can burn quickly and be devastating if not detected and extinguished. In the drier seasons, the dangers of a bushfire occurring are very high. They can be caused by lightning, deliberately lit or started accidentally. A bushfire can destroy homes and buildings, devastate crops, and threaten the lives of people and animals.
There are a number of bushfires that come under the disaster banner, including:
- Victoria, 2009, in which 173 lives were lost. This is now referred to as Black Saturday.
- South Australia and Victoria, 1983, which claimed 76 lives and was named Ash Wednesday.
- Southern Victoria, 1969, when 23 people lost their lives.
- New South Wales, 1968, in the Blue Mountains and coastal region, where 14 lives were lost.
- Hobart and Southern Tasmania, 1967, where 62 people perished.
- Victoria, 1939, known as Black Friday, when 71 lives were lost.
Bushfires in Australia occur either as a grass fire or forest fire.
These usually occur on grazing and farm land, although they may take place in remote scrub country, and can claim lives or destroy fences, livestock and buildings.
Australia’s forests are largely made up of eucalypt trees that once alight are very difficult to control and extinguish due to the high amounts of flammable vapour from their leaves. This causes large fireballs in the upper storey of the forest and large clouds of smoke that blanket the ground and make aerial observations difficult.
Causes of bushfires
Bushfires can be caused deliberately or accidentally. Some of these causes are:
- leaving a fire unattended (at a camp, barbeque)
- having an open fire on a dry windy day
- small flames resulting from glass bottles or mirrors that become a larger fire
- failing to put out a cigarette or match properly
- deliberate lighting of fires with the intent to cause damage, which is known as arson.
- flammable chemicals that are left in the sun or hot areas.
Ways to control bushfires
Bushfires are fought by trained volunteer firefighters and Emergency Service personnel who have access to the appropriate equipment. Helicopters and light aircraft are used to observe the fire. They can help to:
- determine the direction the fire may take
- decide where to make firebreaks
- locate nearby homes, businesses, other buildings and livestock.
All of these observations allow the State and Territory Emergency Services to better understand the fire and devise useful plans for evacuation.
Water planes are used to control and extinguish spot fires (small fires which jump ahead of the main fire front) using a technique called water bombing.
Bulldozers are another effective piece of firefighting equipment and are used to create emergency firebreaks. Back-burning an area just before the bushfire season is an effective strategy to minimise the chance of a bushfire.
Did you know?
- South-eastern Australia includes areas which are prone to the most severe and frequent wildfires in the world.
- A fire front is the leading edge of a moving fire.
- Most firefighting deaths have occurred following a sudden change in wind direction. In bushfires, radiant heat from flames, dehydration and asphyxiation from smoke are the major killers.
- In drier seasons the fire danger is much higher.
- On 7 February 2009, the Black Saturday bushfires in Victoria became Australia's most damaging bushfires with an estimated cost of $1 billion and the loss of 173 lives.
- On 21 January 1997, over 250 bushfires burnt across Victoria as the temperature soared to 41.2°C. Over 40 homes were destroyed in the Dandenong Ranges, near Melbourne.
- The 1994 eastern seaboard fires in New South Wales burnt about 800,000 hectares of land including sections of Sydney suburbs and 40 national parks.
- In 1982/83 south-east Australia experienced severe drought conditions. On 16 February 1983, Victoria and South Australia experienced a very dry, hot and windy day. In Melbourne the temperature reached 43°C with relative humidity of 6 percent. The Ash Wednesday bushfires erupted on this day. These fires claimed 76 lives and had a total estimated cost of $975 million.