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Wildfires (Causes (Drought, Falling power lines, Matches, Climate change,…
Wildfires
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Nature
Occur when oxygen combines with carbon, hydrogen and other organic material, producing flame, heat and light. During fire solar energy stored in plants is returned back to atmosphere, large wildfires are most serious, 95% of areas burned= caused by 3% of all fires
Occur at different levels, sweeping through vegetation in different ways
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Very hot, 540-1100 degrees
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Number of different stages- (1) Preheating, (2) Flaming combustion, (3) glowing combustion
Pyrolysis= chemical reaction causing organic material to decompose, Flaming combustion= burn wood and organic matter and release energy, wood itself doesn't burn as well and my be affected more by slower and less dramatic process of glowing combustion
Shouldn't always be seen as negative, often a means of regeneration within ecosystems, Farmers and national park rangers use controlled burning and minerals released are beneficial to the soil. Certain species such as Baobab tree can withstand fire through thick bark tissue and high moisture content, form of adapted plant= Pyrophytic vegetation, Bushfires in Australia and Canada= out of control and not managed= real hazard
Responses
Response
Supress the fire, Reduce fuel supply, Aid
Adaptation
Hazard-resistant design, Firebreaks, Fire resistance, Education, Land-use planning, Fire resistant construction methods, Insurance
Preparedness
Insurance, Warning systems, Community preparedness, Evacuation
Mitigation
Firebreaks, USA and Australia= controlled burning, 50% reduction in fuel results in 50% reduction in spread of fire and 75% reduction in intensity
Favouring conditions
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Fuel
Plants/ vegetation= main source, needs to be enough and dry as well as suitable climate conditions
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Impacts
Primary
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Crops and livestock may be damaged (S, EN, EC)
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Peoples property and homes can be destroyed (EC, S)
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Air quality may be affected, with smoke causing respiratory problems (EN,S)
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People may have to evacuate the area and seek temporary shelter (S, EC)
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Secondary
With vegetation burnt, less interception may increase flood risk (EN, S)
Timber can be burned- the industry provides jobs and income (EC, S)
Ashes from the fire may ultimately add fertility to the soil (EN, EC, S)
Small fires occurring regularly reduce fuel build-up, preventing a bigger fire (EN)
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Distribution
Rural areas, dry enough but wet enough for vegetation to grow, seasonal, S America, Africa, Australia= worst