CONCEPTS in Action

Firefighting

Uncontrolled fires threaten lives and property and can have a devastating effect on the environment. To fight fires, it is necessary to understand how they start, and what sustains them.

Fire is the result of combustion, a rapid reaction between oxygen and fuel. During combustion, fuel and oxygen react to form carbon dioxide, water, and heat. Most fires in rural areas, called wildfires, are caused by people being careless with campfires or cigarettes. Arson and lightning are also common causes. Usually the fire starts in an area of dry grass, which will ignite at a temperature of 150–200°C. Burning grass can create enough heat to ignite bushes, and these, in turn, may be tall enough to carry the flames into trees. (Wood has a higher ignition temperature, around 260°C.) Environmental conditions, such as drought that has left vegetation dry, and strong winds, can cause a small fire to spread. Wind also carries fire forward into new areas. Burning twigs and branches that become detached from trees can be blown into new areas of vegetation.

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