Bushfires

These blazes can occur over many different parts of our continent, at various times of the year. However, because of population distribution, it is south-eastern Australia that experiences most of our highly destructive fires. All the major capital cities in the area - Sydney, Melbourne, Canberra and Hobart - have been menaced by major conflagrations that have destroyed huge tracts of surrounding countryside.

South-eastern Australia is highly prone to bushfires for three main reasons. Firstly, periodic droughts can rapidly dry out the large areas of highly flammable eucalypt forests that predominate across the region, producing heavy covers of tinder-dry vegetation.

Then there are the local weather patterns that periodically develop. During the summer and autumn months in particular, passing cold fronts often follow hot and dry northerly winds that scour the area, producing high temperatures, low humidity and strong wind gusts, a combination that produces the perfect recipe for bushfires. Also, these fronts often generate sudden wind changes as they pass. The hot northerlies can suddenly change to strong west to southwest winds, resulting in unpredictable changes in fire behaviour.

Finally, there are several methods of ignition. Thunderstorms associated with passing cold fronts can generate lightning strikes that set fire to the vegetation. And because of the concentrations of people in the area, human-induced fires are sometimes lit by machinery, clashing powerlines and even arson.

Three of the worst examples in recent history are:

Black Friday: Victoria
Friday 13th January 1939
71 deaths, 1300 homes destroyed

Ash Wednesday: Victoria and South Australia
Wednesday 16th February 1983
75 deaths, 2500 homes destroyed

Black Saturday: Victoria
Saturday 7th February 2009
171 deaths, 1800 homes destroyed