wildfire hazards Flashcards
wildfire
a wild uncontrolled fire that quickly spreads through vegetation
conditions favouring intense wildfires
vegetation type, fuel characteristics, climate and recent weather
vegetation type
thick, close together vegetation allows fires to spread quickly and easily. (trees and thick bushes)
fuel characteristics
dry conditions allows vegetation to catch fire, finer vegetation causes fire to spread quicker but thicker vegetation burns for longer and more intensely
distribution of wildfires
occur in a climate that has enough rainfall for sufficient plant growth but considerable dry spells and droughts to dry out the fuel. Areas with dry seasons allow for intense wildfires (California)
climate and recent weather
Wind allows fires to spread much quicker
El nino effect
recent temperature increases cause increased amount of wildfires
El Niño effect
provides dry season (Australia) creating more wildfires
fire behaviour
fire spreads quickly on hills as the heat rises, fire spreads in every direction
crown fires
burn the entire tree bottom top - most dangerous and destructive fire
surface fires
only burn the leaf litter - easy to extinguish
ground fires
burns beneath the surface and moves slowly through dried underground. difficult to put out - due to being underground
causes of wilfires
natural -lightning, volcanoes, spontaneous
human - cigarettes, bbqs, agriculture, train lines..
environmental effects
primary - air pollution from ash, water pollution, habitats destroyed, toxic gases realeased
secondary - removing invasive species, migration patterns of animals affected, increases CO2 from fires heighten greenhouse effect
economic impacts
primary - businesses destroyed, agricultural land damaged, cost of fighting fires
secondary - high cost of rebuilding and insurance payout, sources of income lost, discouraging visitors, losing tourism sector, planes cancelled
social impacts
primary - people killed or injured, homes destroyed, missing people
secondary - homelessness, food shortages, health problems (asthma)
political impacts
primary - government buildings destroyed
secondary - borrowing money for international aid, pressure for government to do more about global warming
prevention and preparedness
wildfires cannot be avoided but public awareness can prevent the ignition of wildfires
be prepared by having evacuation plans, emergency service training and drills.
warning systems let people know when there are perfect conditions
evacuation zones
mitigation
controlled burnings - burning created on purpose to remove flammable materials so that less fuel is available. fire breaks (gaps in trees) - created to limit spread
adaptation
There is the argument that perhaps we should not intervene in wildfires at all, which can be classed as a fatalistic outlook. Many people believe it is not worth the money or resources to extinguish wildfires if they are only going to start again, and some should just be left to burn. There are also ecological benefits of having wildfires burn, which supports the idea that we should adapt to wildfires and let them burn.
