What is a wildfire?
A large, uncontrolled fire that quickly spreads through vegetation
What are the types of wildfire?
- Ground fires -> burn beneath the ground surface with tree roots and peat layers burning
- Surface fires -> burn through low-lying vegetation such as grass, bushes and small trees -> most common, can move quickly
- Crown fires -> burn through the canopy layer which is the top layer of vegetation -> most dangerous and destructive, move quickly and produce intense heat and flames
What is the distribution of wildfires?
- Occur all over the world except for Antarctica and the Arctic
- Most common in the tropics and subtropics -> eg. Brazil, Australia, Indonesia have the highest number of wildfires
- Also common in large, forested areas of dense vegetation -> eg. Russia, Canada, USA
What are types of conditions that can favour intense wildfires?
- Vegetation type
- Fuel characteristics
- Climate and recent weather
- Fire behaviour
How can vegetation type favour intense wildfires?
- Denser vegetation tends to lead to more intense fire -> forest fires tend to be more intense and dangerous than grassland fires
- Eucalyptus contains highly flammable oils that burn easily
How can climate and recent weather favour intense wildfires?
- Dry weather, droughts and high temperatures dry out vegetation and increase flammability
- Strong winds can fan flames of a fire and cause it to spread more -> eg. Diablo and Santa Ana Winds in California, Carr Fire in California 2018 spread rapidly due to strong winds and dry vegetation
- Lightning storms are a common cause of wildfire ignition
- Climate change increasing frequency and severity -> eg. Wildfires now destroy twice as much tree cover as they did 20 years ago
What are the causes of wildfires?
Natural - lightning strikes, volcanic eruptions, heat from sun
Human - lit cigarettes, BBQs, campfires, arson
What percentage of California wildfires from 2015-2020 were caused by arson, human and natural factors
Arson - 10-15%
Human factors - 86%
Natural factors - 14%
Outline the Black Summer Bushfires in Australa
- 2019 Sep - 2020 March
- 2019 was Australia’s driest and hottest year
- Much of Australia’s forest is made up of highly flammable eucalyptus trees
- Some fires lit deliberately, some by lightning
- Over 20% of Australia’s forests burned
What were the primary impacts of the Black Summer Bushfires?
- 33 deaths
- 80,000 displaced
- 60,000 buildings damaged or destroyed
- Cost $5 billion
- Estimated 3 billion animals killed/displaced
- Over 400 million tonnes of CO2 released
- Morrison (Australian PM) faced intense criticism during the fires as he was reported of being on holiday
What were the secondary impacts of the Black Summer Bushfires?
- Disruption to tourism, agriculture, forestry -> cost over $4 billion
- 450 died from smoke inhalation
- Cost of firefighting over $2 billion
- Smoke depleted ozone layer by 3-5%
- Increased soil erosion and loss of soil fertility due to lack of vegetation
What were the immediate responses to the Black Summer Bushfires?
- 80,000 firefighters from Australia, New Zealand, Canada and USA tackled the fires
- Temporary accommodation set up in sports centres and community halls for 50,000
- The Salvation Army and Australian Red Cross provided food packages at evacuation centres
- Australian Defence Force helped evacuation by air
What were the long-term responses to the Black Summer Bushfires?
- Government committed over $2 billion to bushfire recovery and financial support to communities and businesses - > creation of National Bushfire Recovery Agency to support those impacted
- Environmental restoration -> creation of koala hospital
- Invested over $2 billion in preparedness, including satellite fire detection and forecasting systems
Outline methods of preparedness for wildfires
- Education - eg. Smokey Bear is an 80 year old US mascot used to provide information on preventing wildfires, eg. Safe grilling/BBQs
- Evacuation routes and zones set up using Thermal Infrared Satellite Imagery and computer modelling to identity areas of lowest risk
Outline methods of mitigation/prevention for wildfires
- Firebreaks can be used to reduce the changes of wildfires spreading by creating deliberate gaps in forested areas
- Backburning is a strategy where firefighters light small fires ahead of a large wildfire to reduce the amount of fuel available -> used during Australia 2019-2020 Black Summer Bushfires, but effectiveness was limited because many forests were too flammable for controlled fires
Outline methods of adaptation for wildfires
- Using fire resistant materials for buildings (eg. metal roofs, brick, concrete)
- Land use planning -> eg. South Korea is planting fire resistant, broad-leaved tree belts near residential areas
Outline monitoring during the Black Summer Bushfires
- New South Wales used the Fire Watch System which use satellite detection and was updated every 10-20 mins
- Fires Near Me app provided live fire locations, warning levels and spread
Outline prediction during the Black Summer Bushfires
- Bureau of Meteorology produced Fire Danger Rating (FDR) maps daily
- NSW Rural Fire Service use the Phoenix Rapid Fire model to simulate fire spread
Outline protection during the Black Summer Bushfires
- Use of water-bombing equipment towards the South Coast
- Backburning used in the Blue Mountains area
- Firebreaks used in Alpine National Park
Outline planning during the Black Summer Bushfires
- NSW Rural Fire Service pre-positioned fire trucks
- Residents advised to evacuate before peak fire days
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Systems15
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The Water Cycle30
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The Water Cycle - Rivers23
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Spatial and Temporal Change20
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The Carbon Cycle34
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Amazon Rainforest Case Study20
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Coasts42
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Odisha Case Study11
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Hazards43
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Mount Nyarigongo Case Study8
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Wildfires20
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Seismic31
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Tropical Storms10
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Tropical Storm Case Studies9
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Multi Hazardous Environment - Japan11
