Wildfires Flashcards
(13 cards)
What are the three types of wildfires?
Ground fire
Crown fire
Surface fire
What’s a surface fire?
Most common
Burn along the forest floor
Burns leaf litter and fallen branches
Burn around 900oC
Cool quickly
Relatively easy to control
What’s a ground fire?
Burn organic matter in the soil (peat)
Spread slowly
Smoulder at low temperatures (540oC)
Can burn for long periods of time
What are crown fires?
Burn through the canopy
Can spread through loose bark, burning whole trees
Burns at over 1100 °C
Most intense
Most difficult to contain
Why do wildfires spread?
Lack of precipitation
Build up of plant material
High(er) temperatures
Wind (direction, speed and humidity of air)
Mismanaged forests
Increased human activity
Type of vegetation – it may actually have flammable resin within it
Topography of the area (through slope, draft created, aspect, barriers, ravines and gullies etc.)
What are the stages of wildfire growth?
Stage 1: Preheating
Water is expelled from plants by nearby flames, drought or a hot day. Gases are released as the temperature rises and the wood breaks down by pyrolysis.
Stage 2: Flaming combustion
The wood burns fast and hot as the gases burn, cracks develop in the wood and release more gases and flames, oils and resins. Energy is released by convection and radiation. Since wood is a poor heat conductor, the inside of the log may not burn unless the process of pyrolysis continues.
Stage 3: Glowing combustion
Wood burns more slowly and at a lower temperature as fire consumes the wood itself instead of the gases released by pyrolysis.
What are the Political impacts of a Wildfire?
Conflict between neighbouring countries due to crross air pollution
Reduced confidence in the government
Implementation of new regulations as a result of fire
What are the social impacts of a wildfire?
Death
loss of income
Increase in respiratory diseases
Residential properties destroyed
Ongoing stress/depressing
What are the economic impacts of a wildfire?
Cost of damamge to rebuilt homes
Tourism decreased
Damage to communincation&buildings
Loss of economic production
Insurance cost rising
What are the environmental impacts of a wildfire?
Contaminated water supplies with ash
Crops and animals destroyed
Habitats destroyed
Localised climate change
Faster surface run off in vegetation-depleted areas
What are the short-term responses to wildfires?
Fill as many containers (pools, hot tubs, garbage cans, etc. with water).
Place lawn sprinklers on the roof and near any above-ground fuel tanks.
Wet the roof.
Place a ladder against the side of the house.
Turn on as many lights in the house as possible. This increases the house’s visibility through smoke.
Close windows and doors but leave them unlocked for firefighters’ easy access
Emergency response occurs among professionals as well as affected individuals. The first aspects of recovery include local agencies that are nearest to the disaster: firefighters, Emergency Medical Services, local police.
Assessments must be conducted to determine the basic human needs that are present and efforts are taken to ensure these needs are met as quickly as possible. Assignments are delegated depending on the current needs - search and rescue, distribution of resources, immediate temporary relocation for displaced individuals
What are the long-term responses to wildfires?
Recovery, in terms of emergency management, refers to providing immediate support to a community affected by a disaster in order to repair the infrastructure and return the community to normal operation status.
In terms of wildfires, post disaster recovery efforts following a wildfire begin with assessing fire damage to trees, shrubs, and soil. Wildfire recovery strategies are dependent on the intensity of the fire (scale of low to high), which determines the extent of fire damage and effective forest restoration. Low intensity fires consist of minimal damage to small trees without burning all of the forest and the majority of leaves still remain on the trees.
How do we manage wildfires?
Removal of leaf litter via controlled burning
Monitoring via satellites
Turn on lights so properties are visible through smoke
Evacuate homes
Distribute aid
Douse fires with water
Build protected homes
Create fire breaksq
