wildfires

• 3 types of fires:

  • surface
  • crown
  • ground
• surface fires burn leaf litters + grasses , travel over ground, easiest to put out
• crown fires spread up trees , most intense wildfires
• ground fires burn underground in dry , peaty soils and move slowly
• benefits of wildfires:

  • benefit ecosystems in mediterranean climate regions + savannah grasslands
  • clear vegetations , helps seeds germinate , get rid of parasites
• costs of wildfires:

  • cause widespread destruction
  • kill wildlife
• areas with dry seasons or semi-arid climates most likely to b affected , including parts of Australia , USA , canada and southern europe
• plants that can withstand fire:

  • yellow pine tree
• firebrands are burning debris that fires throw out and it helps fires spread. Fires become more intense
• thick vegetation undergrowth and closely spaced trees helps fire travel easier
• dry vegetation causes wildfires - caused by warm weather
• strong wind = more oxygen to help fire burn, spreads burning embers
• wildfires normally occur after droughts
• a material's flashpoint is the point in which something will burst into flames
• woods flashpoint is 300 degrees
• when wood's flashpoint is ignited , it releases hydrocarbons which mixes with oxygen. It combusts and causes a fire
• human causes of wildfires include:

  • slash and burn
  • arson
  • accidents
• arson attacks account for 30% of wildfires
• slash and burn is a farming method used to clear land in order to grow crops. They often get out of control and cause fires
• physical causes of wildfires:

  • spontaneous heating
  • lightning
  • earthquakes and volcanoes
• El Niño is a natural process that occurs every 6-8 years. It is the warming of the central-eastern equatorial Pacfic.
• fatalism approach to wildfires is that we shouldn't intervene in wildfires at a;;
• why do people take a fatalist approach towards wildfires?

  • not worth money or resources if fires just start again
  • ecological benefits
• firebreaks are strips of bare ground between vegetation which prevent fire from spreading.
• the main problem with using firebreaks as a hazard management technique is they can be expensive to create, especially on steep slopes where it may not even work.
• the main types of fuel are grass, shrubs, trees and peat bogs.
• what happened in Jasper, Alberta?

  • lots of wildfires extinguished there , forest is thick and deprived of light
  • prevented growth of silver birch trees , forest = mainly pine
  • Mountain pine beetle has taken over forest , affected ecosystem and many trees have died
• methods of predicting wildfires

  • broadcasted weather warnings warn people for perfect weather conditions for wildfires to occur
  • warning systems
  • thermal infrared satellite imagery shows where wildfires are occurring - evacuation zones can be set up
• adaption techniques for wildfires

  • make sure new buildings are resisting to fire hazards
  • Australia's 'stay or go' policy encourages people to protect property or evacuate. Those who 'stay' have a deep fire shelter dug into ground they can escape to
  • clearing vegetation away from homes , using fire retardant materials
  • creating fire breaks to stop fire spreading
• wildfire prevention techniques

  • pubic education about risk of using campfires and barbecues
  • authorities may provide people with fire beaters
  • Smokey Bear campaign - 70 year old US mascot , provides people with information on preventing wildfires. 8/10 people recognise the bear
• management techniques of wildfires


  • main focus is to ensure people can evacuate quickly
  • search and rescue
  • recovery of bodies
  • aid
  • fire beaters and fire-breaks
• risk sharing

  involves sharing cost of reducing a hazards , the benefits of preventing it or the costs of not preventing it - e.g people buy insurance to help them repay their property after a disaster
• spatial and temporal distribution of wildfires


  • common in areas with wet seasons in which vegetation thrives and then prolonged dry season characterised by high temperatures and extended drought e.g mediterranean climates e.g Southern Spain , Italy or Greece
• why are wildfires common in continental interior?


  because there is no moisture as air travels over rest of country and leaves little rainfall for areas further inland