Bushfires

Students Learn About

• the nature of the natural hazard in Australia • the geographical processes involved• the impacts of the natural hazard: • economic• environmental • social

Students Learn To

• describe the geographical processes associated with the natural hazard

• describe the economic, environmental and social impacts of the natural hazard in Australia

History

• Bushfires are fires burning out of control in the open using grass, scrub or a forest for fuel

• Fire has influenced the development of Australian land since the last ice age

• Fire is essential to some ecosystems, some plants require intense heat to release seeds that replenish growth

• Aborigines used fire for hunting activities• European settlers used fire to clear land

History

• Using fire to clear land, for hunting etc. is now banned, as a result leaf and bark litter has increased and provides fuel for bushfires

Cause

• Bushfires can start naturally through lightning strikes and spontaneous combustion

• Most bushfires are started by people e.g. discarded cigarettes/matches, electricity cables, sparks from tools and burning off

Types

• There are two main types of bushfires:• Surface bushfires: burn in grass, low shrubs and ground

litter. Travel at high speeds but are easier to control• Crown bushfires: occurs when heat and flames from a

surface fire ignite the crowns (tops) of trees. These fires spread rapidly with strong hot winds and dry vegetation. Flammable eucalyptus is particularly dangerous and makes these fires hard to control

Where

• South eastern Australia is most prone to bushfires (central Australia is too arid and there’s not much to burn) this is because:• Large sclerophyll forests with a dominance of eucalyptus

trees (highly flammable oil). Trees burst into flames. Fortunately, for the eucalyptus during this trauma they drop new seeds and can easily regrow.

• Area is prone to prolonged periods of low rainfall/drought.

Where

• The area is prone to heat waves and strong northerly winds during summer months

• Climate change experts predict this area to become hotter and drier in the future

Response

• The results of bushfires include loss of life/injury and personal/financial hardship to families and communities

• 70000 individuals volunteer for the bushfire brigades

Black Saturday

• Black Saturday in Victoria 7th February 2009 killed 173 people and destroyed 2029 homes.

• Causes of the bushfire included: heatwaves, low rainfall, winds, low humidity, topography (i.e. hilly land), human factors (i.e. people electing to live in forested areas)

Other Major Bushfires

Location Date Deaths Homes Lost

Hectares Burned

Cost at the Time

Tasmania Feb 1967 62 1300 260000 $45 mil

Victoria Feb 1983 75 2400 500000 $400 mil

Portugal Aug 2003 15 500 140000 US$1 bil

California Oct 2007 23 1500 200000 US$1 bil

Greece Aug 2007 64 1500 11000 US$1.2 bil

Victoria Feb 2009 173 2029 450000 $1.5 bil