GoConqr has a new look! Let us know what you think.

Sign up free

Flashcards

wildfires

serena norman thomas Geography GCSE English 27 cards

Cards in this deck (27)

  1. 1what is a wildfire?- term used for uncontrolled fire fuelled by natural vegetation
    - in Australia = bush fires
    - North America = brush fires
    - often start in rural, wilderness areas but migrate to rural-urban fringes, affecting buildings, animals+people
  2. 2what are the 3 types of wildfire?- ground fire: where ground itself (peat, tree roots) burns, slow, smouldering fire with no flame+little smoke
    - surface fire: where leaf litter+low-lying vegetation burn, can be low or high intensity
    - crown fire: where fire moves rapidly through canopy, likely to be intense+fast-moving
  3. 3for a natural fire to occur, what 2 things are needed?- an ignition source: lightening = main cause, climate will affect frequency of electrical storms, particularly one where there's hardly any rainfall, increasingly as a result of humans, e.g. falling power lines, discarded cigarettes, camp+agricultural fires
    - fuel: has to be of sufficient quantity+dry enough to burn, climate affects frequency+duration of droughts, type of vegetation that will grow in an area+rate @ which litter is produced
  4. 4how does the vegetation type affect the intensity?- thick undergrowth or closely spaced trees allow fire to travel easily
    - some trees like eucalyptus+pine contain a lot of oil+so burn easily
    - eucalyptus trees shed strips of bark which help it spread quickly
  5. 5fuel characteristics?- fine, dry material (e.g. long grass, thin twigs) catch fire+burn most easily
    - large amounts of fuel that form continuous cover will help fire burn for longer+spread
  6. 6climate+recent weather?- rainfall must be sufficient enough for vegetation to grow, so plenty of fuel
    - area usually has distinct dry season where rainfall = low for significant time, warm+dry weather causes water in vegetation to dry up > more flammable
    - strong winds provide more oxygen to help fire burn+spread burning embers
  7. 7fire behaviour?- fire burns in different ways, e.g. creeping fire moves across ground surface fairly slowly, running fire spreads rapidly+is more intense
    - can throw out burning debris (firebrands) that help it spread+become more intense
  8. 8where are wildfires likely to occur?- areas with combination of dry vegetation+lightening strikes
    - areas with dry season, e.g. semi-arid climate+susceptible to drought
    - mediterranean climate regions+savannah grasslands
    e.g. parts of Australia
    e.g. US+Canada: Cali+Alberta
    e.g. Southern Europe: Italy, Greece
  9. 9can fires aid new seed germination?yes
    - they clear vegetation
    - stimulate growth of certain plants+rid area of some insects+parasitezs
  10. 10what is pyrophytic vegetation?- pyrophytes = plants adapted to tolerate fire
    - through mechanisms like resistant bark, e.g. baobab tree
  11. 11what is a good example where wildfires are a continuing problem?- LA Basin in California
    - much of area covered by drought resistant chaparral, after summer drought can be tinder dry
    - dry wind: Santa Ana increases dryness to point where an ignition could easily cause a major fire
    - large area of low density housing+large amounts of vegetation exposed
  12. 12what are the physical factors that affect the extent of impacts?- frequency/regularity of fires
    - magnitude
    - length
    - amount of fuel
    - wind
    - hot,dry weather
  13. 13what are the human factors that affect the extent of impacts?- community preparedness
    - risk management (b4, during+after)
    - level of education
    - past experience
    - occupation/employment
    - vulnerability
    - population density
  14. 14what are the social effects?- loss of life: most are away from people but some move so fast ppl can be trapped, e.g. Victoria 173 deaths
    - loss of property: due to urban expansion more communities @ risk, e.g. Sydney+LA, can cause homelessness
    - toxic gases+particulates: Southeast Asia 'haze' = large scale air pollution > respiratory problems
  15. 15what are the economic impacts?- loss of crops+livestock: have huge impact in timber producing areas, may take years to replace trees
    - in USA estimates $10 million spent fighting fires a day
  16. 16environmental?- loss of wildlife: Indonesia fires of 1997 destroyed Wein River orangutan sanctuary on Kalimantan
    - increased flood risk: rain comes in heavy bursts + loss of so much vegetation + so interception > flooding
    - damage to soil structure+nutrient content: intense heat generated @ ground level > destroy nutrients+alteration in soil structure
  17. 17political?- evacuation: many flee+not allowed back into affected area so emergency shelters/accommodation will have to be provided with food, etc
  18. 18explain 'managing the vegetation'- controlled burning to get rid of little
    - creating firebreaks in vegetation in advance rather than during
  19. 19explain 'managing the built environment'- increased gap between houses+vegetation
    - incorporating more fire resistant methods in construction, e.g. stone+brick rather than wood, spark arresters to chimneys
  20. 20explain 'modelling'- studying ways in which fires behaviour with computer stimulations to comprehend+predict fire behaviour
  21. 21explain education- make people aware regarding home safety+how to avoid starting fires
  22. 22explain warning systems- put in place by establishing lookout towers+air patrols
    - tourist areas notice boards @ strategic locations
  23. 23explain being well insured- wealthier countries people urged to take out insurance against fire damage
    - can be very expensive in fire prone areas
  24. 24how can the event be dealt with as it happens?- fighting fires as they happen
    - very dangerous
    - spraying with water+chemicals from ground+air
    - work on ground beating out flames+bulldozing large breaks in vegetation preventing fires jumping certain directions
    - retardants to slow pace of wildlife sprayed on fires which are inaccessible or where human safety+structures endangered
  25. 25explain replanting trees 1- particularly in commercial forestry areas to improve economy of areas devastated by fires
  26. 26explain replanting trees 2- after vegetation removed by fire + great danger of flooding+mudslides on unprotected slopes
    - planting trees will stabilise slopes
  27. 27explain preparedness- making sure people are better prepared for next fire by having emergency supplies ready, survival kits
    - setting up community groups, e.g. Victoria

Information

Description
GCSE Geography (hazards) Flashcards on wildfires, created by serena norman thomas on 21/05/2018.
Views
0
Rating

More on Wildfires

Feedback

What is it about?

What do you think of the new look?

How do you like it?