Why Do Bushfires Occur?
There are a
number of differernt reasons a bushfire happens, most causes are from
human activity rather than a natural cause.
Lightning Strikes (Natural Cause)
Lightning strikes are a way a bushfire is started. Lightning strikes are how 26% of bushfires are started and it is the most common individual way a bushfire is started too. Thunderstorms are started wth the cold air starts moving over the warm air in the sky. The warm air's heat energy is turned into an electrical discharges and wind.
The force
from the charge of the cloud and the ground will soon become too great
and sparks will start breaking through downwards towards the ground. As
they fall to the ground, the positive charges will send some of its
sparks upwards. When the 2 sparks meet, the circuit is closed and
lightning is seen. Lightning generally strikes the highest object there
(usually trees and plants).
Agricultural Fire (Human Cause)
Some farmers use fire to burn weeds, unneccessary plants and etc. However these fires have been known to be lost control of, and when it is lost control it will start to burn through everything and spread quickly through the trees, bushes and plants. Agricultural fires contribute to 15% of the causes of bushfires.
Human Carelessness (Human Cause)
Human carelessness has also contributed to the starting of many bushfires. Human carelessness could range from an out of control campfire, disposing a cigarette which ignites the flora etc. A clumsy mistake like those could start a huge bushfire, an example is during 1998, a campfire is suspected to have been the cause of a bushfire which burned 32 000 hectres in the Alphine region of Victoria.
Other Causes (Human Cause)
Other causes may include car crashes which often results in flames and it could spread causing a bushfire. Machinery can produce sparks which could also start a fire, these include chainsaws, wielders etc. Arsonist have also been known to start a bushfire by deliberately starting a fire. Eletrical cables that have broken down could also send a spark, bursting a nearby tree or plant into flames.
Image courtesy of Bushfire Protection Services
