Fire in the Earth System Notes

The Earth Surface System

  • The Earth Surface System comprises various interacting components:
    • Climate
    • Hydrological Cycle
    • Oceans
    • Coasts
    • Atmosphere
    • Slopes
    • Rivers
    • Geosphere
    • Fire
    • Glaciers
    • Biosphere
    • Lithosphere
    • The Geographer's view

Fire in the Earth System

  • Fire in the Earth System
    • Questions:
      • What is Fire?
      • How do fires occur?
      • Ignition sources
      • Fire Regimes
      • What is the impact of fires on landscapes and ecosystems?

Fire: The Ingredients

  • Fire requires three key ingredients, forming the Fire Triangle:
    • Fuel: Any combustible material, most often vegetation.
    • Ignition Source: A heat source to start the fire.
      • Lightning: A high-temperature heat source (Lighting 4x as hot as the surface of the Sun!).
      • Volcano
      • Rock fall spark
      • Humans
    • Oxygen: An atmosphere with at least 21% oxygen is required.

Fire: Byproducts

  • Water
  • CO2CO_2

Global Lightning Activity

  • Figure 1.3 depicts global lightning activity as the number of flashes per square kilometer per year.
  • Data is available from the Global Hydrology Resource Center.

Human Population Change

  • Human population change: 1700 to 2000 AD HYDE 3.0 Data: http://www.mnp.nl/hyde/ ftp://ftp. mnp.nl/hyde/hyde30/pop (5 min. data) Image: Dept.Geography Univ. Oregon [http://geography.uoregon.edu/envchange/]

Humans and Fire in the Western U.S. (1986-1996)

  • Lightning-Started Fires
    • 0-50
    • 50-500
    • 500-5000
    • >5000 ha
  • Jan Human-Started Fires
    • <- 0-50
    • 50-500
    • 500-5000
    • >5000 ha

The Wildland-Urban Interface

  • The wildland-urban interface