Wildfires Flashcards
3 types of wildfire
ground - ground burns eg peat and tree roots
slow and no flame, little smoke
surface - leaf litter and low lying vegetation burns
high or low intensity
crown - fires move rapidly through canopy
likely intense and fast moving
conditions that favour wildfires
vegetation type
- thick and dense
- some trees contain oil, more flammable
fuel - fine and dry material
recent weather
- rain to allow vegetation to grow for fuel
- needs dry season to become flammable
- winds provide oxygen and help it spread
fire behaviour - firerbrands spread it more
- burning debris thrown
natural causes
lightning
volcanic eruptions, lava
human causes
dropping of cigarettes
campfires
fireworks
arson, on purpose
80% human in USA
prevention
education on campfires and safety
campfire bans in dry weather
preparedness
evacuation plans
warning systems for early detection - satellite and infrared
create defensible space
adaptation
emergency plans and shelters
education and preparation
creating defensible space between houses, stop spread
non-flammable materials for houses
mitigation
monitoring and warnings - satalites with infrared
evacuation plans
insurance
backburning - small fires lit to reduce amount of fuel for larger ones
firebreaks - gaps in forest to reduce spreading
impacts of wildfires
social
- death
- homelessness
economic
- businesses destoryed
- insurance increases
env
- habitats destorced
- soils damaged
- smoke causing air pollution
how is climate change effecting wildfires?
Average wildfire season 78 days longer
Climate change - hotter and drier climate, spreads more easily
more area drier for longer, occur in more places
creating favourable conditions
but 80% human, not always factor
urbanisation also increasing risk
conditions needed for wildfires
supply of fuel eg vegetation
ignition source - human or natural
oxygen - winds also help spread
vegetation characteristics that favour wildfires
effects intensity and rate of spread
quantity depends where
thick vegetation, closely spaced = ideal
some trees contain oil - more flammable eg eucalyptus
fine dry material burns easily
wildfires travel faster uphill
climatic conditions that favour wildfires
- rain to allow vegetation to grow for fuel
- needs dry season to become flammable
- winds provide oxygen and help it spread
cyclical climate events - El Niño can cause favorable conditions
how does El Niño effect wildfires?
westerly trade winds weaken
creates warmer weather in South America
moves rainfall away from SE Asia and Australia = drier
wildfires more likely
how does fire behaviour effect its spread?
firebrands - burning debris thrown
- allows it to spread easier
wildfires moves faster uphill, steeper slope = faster spread
