What are bushfires?

Basically a bushfire is the combustion or burning of bush, forest or woodland area.

Bushfires are natural phenomena most common in Australia but also occur in many places around the world where there is plenty of wood, leaves or forest that can burn.

more info

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Did you know that bushfires are actually naturally stored solar energy that is out of control? That's because trees convert all that sunlight into oils that get stored in leaves that end up burning like petrol.

Bushfires are also called wildfires, and the US expression may include brushfires or forest fires.

Why are bushfires important ?

There are some obvious reasons for knowing about bush fires:

• Environmentally bushfires can be important to local ecosystems. eg smoke is sometimes needed for seeds to germinate.
  
• bushfire benefits to the environment and recovery
  
  
• Bushfires can have a economic and emotional effect on people and property directly affected.
  
  
• Having a better understanding of bushfire causes can help you better prepare and perhaps minimise or prevent bushfire damage.

  
  Bushfires can cause small cumulus clouds as heat pushes up air. These are called pyrocumulus clouds.

 

Bushfires affect the atmosphere by :

• creating large volumes of smoke and ash.
• causing localised changes in weather.
• increasing the amount of CO₂

The environmental protection authority provides current air quality

For asthmatics the increased smoke in the air can provoke asthma attacks.

A satellite image of smoke trails from bushfires (from CSIRO)

Extrainfo: Global world wide effects of bushfires

News about bush fires.

The Australian bushfire season for 2009 has started, as it does each year during the start of summer.

9 May 2009

Over 30,000 people have fled from bushfires (wildfires) that contnue to burn in the US State of California near homes above the US coastal town of Santa Barba.

More from ABC News

 

1 March 2009

Very extreme bushfire conditions are predicted for Tuesday in Victoria, with winds ranging from 45-70km/h and temperatures of 37. Conditions potentially considered worse than Black Saturday.

More from ABC News

21 February 2009

The Black Saturday Bushfires have claimed 208 lives at the last count with entire townships destroyed including hundreds of properties.

More from ABC News

11 February 2009

The weekend bushfires are now considered the worst ever in Australia's history with over 180 deaths and the toll may increase. There are concerns that several fire fronts may merge due to continued high winds.

More from ABC news

9 February 2009

Over 108 people have now been confirmed dead as a result of the weekend bushfires across Victoria. Over 750 houses have been destroyed and some towns have been destroyed.

more details ABC news

8 February 2009

At least 25 people have died in Vctoria as a result of bushfires. Extreme weather conditions including very high winds and temperatures over 40°C have destroyed towns including over 100 houses.

more ABC news

13 January 2009

A large bushfire has destroyed two houses and some sheds south of Port Lincoln on the Eyre Peninsula.

more from ABC news

6 January 2009

Soaring temperatures, Hot winds are contributing difficulties in controlling three large bushfires burning in NSW.

Of most concern is a a fire covering 100 hectares in Wingecarribee region, south of Sydney according to RFS spokesman ..

also Yango National Park, in the Hunter Valley, Moreton National Park, south-west of Goulburn.

more from Sydney Morning Herald Article

more from ABC News

Australian Road Traffic Authorities phone 13 27 01 provides information about the current road situation including road closures due to fires.

ABC Rural News provides excellent bushfire reports.

Here are some useful links to resources and general information about bushfires

• Current satellite images of all the fires around australia is available from the Sentinal network at Geoscience Australia .

• CSIRO bushfire research
• Bushfire weather from BoM
• ACT Emergency Services Bureau
• NSW rural firesevice
• Victoria Country Fire Authority
• Victorian Department of Sustainability - Fires
• South Australia Country Fire Service
• Western Australia Fire and Emergency Services Authority of WA.
• Northern Territory bushfire council
• Tasmania Fire Service
• Queensland Fire Service

International sites

• Canadian National Forest Fire Report
• United States WildFire fighters

How do bushfires occur?

For a bushfire to start there needs to be fuel, in the form of leaves and/or wood and a ignition flame point.

This ignition can be caused either naturally by a lightening strike, spontaneous combustion or a deliberate/accidental flame.

 

Australian Bushfires are particularly severe as eucalyptus tree leaves contain large amounts of oil that act much like any oil and burn very fast and hot.

So how does a house burn down in a bushfire even if there are no trees are directly touching the house?

Two main reasons:

1. The water pressure at the local tap is too low for fire fighters to do anything.
   
   
2. Wind can send flying embers from the main fire which catch in gutters and ignite leaves or other materials around the house.

remember to keep your property clear of leaves if possible.

Tips for protecting your House 1. people should avoid living in or too close to the bush 2. avoid planting tall eucalypts near their houses 3. reduce fuel load - get rid of leaves, fallen bark, dry wood around houses 4. plant deciduous trees around the house rather than native trees 5. ensure gutterings are clear of dry vegetation. Thanks to Kath O'Brian for this

bushfires and communities,
minimising the impact of bushfires on communties.

Extra Info: Why and how bushfires happen

Extra Info: Backburning in controlling bushfires to prevent spreading

How do bush fires progress?

There are several major factors that affect the progress of a bushfire

• high winds (provide more oxygen)
• amount of fuel( eg leaves)
• low humidity
• high air temperature

All these contribute to the way a bushfire progresses. These factors then combine with the terrain

The kind of terrain, eg hills and slopes, for example fires tend to spread faster up sides of hills.

Additionally flying burning embers of a main fire front can set spot fires ahead. The fire basically basically leaps ahead of itself helped by the wind.

How are plants and animals affected by bushfires?

Plants typically their leaves and bark burn but many plants are adapted to regrow. Though it sometimes depends on how hot the fire is.

A detailed article on plant ecology and biodiveristy of how plants are affected, in some cases benefit from bushfires...Australian National Botanical Gardens

Animals have a much harder time. The only animal able to properly survive are wombats that dig under the ground. Many animals die from smoke or are burnt.

Extra Info : How animals are affected by bushfires

For more info email

see also Geographical processes in bushfires

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What is the history of bushfires?

Bushfires have existed for as long as trees have been around. The kind of Australian trees that tend to burn most vigerously evolved millions of years ago to cope with the dry conditions as Continental Australia drifted slowly towards the equator.

Ash Wednesday bushfires

 

Ancient indigenous aboriginals learned through thousands of years to use controlled burning to encourage new growth of plants.

 

The future of bushfires.

Bushfires will continue to play a role in Australia's ecosystem, economy and social, environoment development. The ability to predict and to combat or prevent fires that threaten people's homes will be come more critical.

Further scientific research into fire behaviour is likely to provide more defences against dealing with this natural phenomena. The CSIRO is actively involved in improving the ability to predict where bushfires are likely occur and how they spread.

Also check out the future of bushfire technology ClearlyExplained.com