Understanding your environment

How does your environment affect fires?

To minimise the impact fires can have on the environment, begin by understanding the shape of your natural landscape, the weather patterns, and the type of vegetation existent in the area. From this, you can develop plans on where you should build your house, how to minimise the spread of fires through the use of fuel reduction zones (or fire breaks), and creating effective escape routes for animals and people.

Weather conditions

For instance, an environment where the humidity in the air is low, the temperature is high, and wind speed is significant, the conditions for creating a fire is greatly enhanced. By checking the weather conditions in your area, you can work out how likely a fire will start, at what times the fires are likely to occur, and what precautions you will need to take.

The slope of the land

Also you should check the slope of the land to determine how quickly a fire can spread and from which direction. For example, flat ground is safer than sloping ground. A steep slope is more dangerous than a gentle slope.

Also fires burn more intensely and spread more quickly when going up a hill, rather than down a hill. This is because the flames can grab hold of a little extra fuel going up the hill and so can burn more quickly and more intensely.

By using this information, you can determine the best position to build a house. For instance, in Australia, a house positioned on a slope that faces east or south is generally safer than a house facing north or west because these are the least likely directions a fire will approach.

The winds

Winds also play a crucial role on the behaviour of fire. A windy day will help to quickly spread a fire. But if the wind is laden with moisture from the sea, the spread of the fire is not as great.

However, if your landscape is such that you are clearly bounded by numerous large hills and the winds have little chance to escape because it forms eddy currents in the valley, or the winds intensify because of a "tunnelling" effect created by the mountains, then the risk of a severe fire sweeping through your area is much greater.

Wind speed and direction is influenced by the topography of the land, the density of vegetation, and the ability of the fire to create its own wind at ground level as it draws oxygen to sustain the combustion.

The higher the speed of the wind, the more capable it is of lifting burning material ahead of the fire front known as spotting. The wind can also push the flames closer to the ground, resulting in the fuel being pre-heated and igniting quicker. This means the fire will spread quickly. If the ground slopes upwards, this effect is amplified even more and the fire will spread more quickly.

There is not a great deal you can do to control the winds except to build solid stone fences and plant fire-resistant trees and shrubs to act as a wind-break at strategic points where a fire is likely to approach. This will at least give you some extra time to prepare yourself for the onslaught of a severe bush fire.

Fire breaks

Once you know the likely direction a fire will come by understanding such things as the slope of the land and the direction of the prevailing wind, you can create special areas or zones to help stop or at least reduce the speed of a fire front sweeping through the area. These zones are called fire breaks.

A fire break is nothing more than an area of reduced fuel. As the experts say, the less fuel there is to burn, the better. So make sure there is an area of reduced fuel (or fire breaks) between the house and the natural Australian bushland, especially where fires are likely to approach.

Make use of natural or man-made fire breaks on your property such as roads, rivers or bare ground to help better protect your house. Fire breaks may also include creeks, swamps and dams.

But don't rely on fuel breaks to protect you, your family and your property. In the event of extreme fire conditions, flying embers can blow across the fire breaks, even very wide fire break zones. These embers will create spotfires ahead of the main firefront and so start another fire of their own.

Generally the bigger the fire break, the better your chances of managing a severe bush fire. But they should never be entirely relied upon in times of the most severe bush fires. They should only be seen as another means of protecting people and the environment from the onslaught of severe bush fires.

Timing is crucial

Part of knowing something about your environment also involves understanding the right time when to have enough water to combat a fire. For example, the greatest chances of experiencing bush fires in the southern hemisphere is between December and February. It is therefore important to ensure adequate water is maintained in dams, tanks and swimming pools during these months if fires are to be properly controlled.

Protecting my house - what can I do?

Finally, the next couple of sections will provide you with a few simple tips you can follow to help better protect your home.