What Causes Fires In Nature? Flashcards
What is the El Nino effect?
- Cyclical climate condition (every 6-8 years)
- Warming of the Pacific ocean (West of South America)
- Affects global rainfall and temperature
- Some areas drought, some areas intense rain
What fire is associated with the El Nino effect?
Alberta Wildfire - 2016
What is the Indian Ocean Dipole
- Cyclical climate event - ocean and atmosphere phenomenon
- During a positive IOD period (cool water in tropical east, warm in tropical west)
- Countries surrounding the Indian Ocean are impacted
- Decrease in rainfall in central/southern Australia (wildfires)
How does lightning cause fires?
- Strikes cause fires to start (most common natural start of fires)
- These are normally small and short lasting
- Only spread quick when conditions are right
How does spontaneous heating cause a fire to start?
- A material is so hot it doesn’t need a spark
- Large amounts of vegetation build heat
- Requires Humid conditions
What are the natural causes of wildfires?
- El Nino
- Indian Ocean Dipole
- Lightning
- Spontaneous heating
What are the human causes of wildfires?
- Accidents
- Arson
- Slash and burn
- Global warming (Enhanced Greenhouse Effect)
How can accidents start fires?
Matches, campfires not put out properly, cigarettes.
Broken bottles x sun rays.
Largest reason for human fires.
What is an example of a fire started via arson?
2009 Australia wildfires.
In some places, this accounts for 30% of wildfires.
What is slash and burn? How does it cause wildfires?
Agricultural practise used to clear land
Gets out of control
Other agricultural/economic causes are machinery sparks, trains, military training and BBQs
How can we prepare for wildfires?
Water planes
How can we prevent impacts of wildfires?
Educational campaigns - Smoky Bear
Controlled fires to limit the spread of wildfires
Plant less flammable trees - avoid Eucalyptus
What are the primary social impacts of wildfires?
Deaths, loss of income
Cost of damage to businesses/residences
Increase in respiratory disease - bronchitis and asthma
Damage to communication
What are the secondary social impacts of wildfires?
Reduced confidence in the government - lack of cooperation at different scales
Mental health depletion
New regulations as a result of the fire - impacts commutes, QoL
What are the primary economic impacts of wildfires?
Cost of damage to businesses
Damage to infrastructure and communication
Crops destroyed - harvest yield is low for that year
What are the secondary economic impacts of wildfires?
Tourism decrease
Insurance costs rise
What are the primary environmental impacts of wildfires?
Species at risk of extinction
Habitats burnt
Faster surface run-off
Contaminated water (ash)
Localised climate change
What are the secondary environmental impacts of wildfires?
Conflict between neighbouring countries due to transnational fires
Cross-border air pollution
What are the potential benefits of wildfires?
New forests (serotinous pine cones drop seeds at fire temperatures)
The previous forest canopy was preventing new growth of seeds
Nutrient source
Reduces likelihood of fire for a while
