Types of Fires

Types of Fires

• classified based on location:

1. ground fire
2. surface fire
3. crown fire

• many fires are a combination of more than one of these

Ground Fire

• it burns organic matter in the soil, beneath the surface litter
• have mostly glowing combustion
• they move relatively slow
• these fires can be hard to notice if small and no flaming combustion
  • the smoke is the giveaway that it’s a ground fire

Surface Fire

• these move along surface of the ground
  • they don’t go up the trees
• they burn only surface litter and undergrowth
• have flaming and/or glowing combustion
• their speed is variable
  • depends on the wind (they move with it)

Crown Fire

• these fires move from the tops (crowns) of trees
• they begin on the surface and migrate up tree trunks
• have flaming combustion
• they spread rapidly if strong winds and steep slopes
• these are very difficult to extinguish

Pyrocumulonimbus Clouds

• wildfires get hot enough and releases so much energy that it creates its own clouds
• hot, moist air released above the fire
  • water vapor is produced by fire
• can grow into thunderstorms
  • produce lightning, cause new fires

Weather and Fire

• fire risk is greatest in areas with the largest differences between wet and dry seasons
  • ex: rapid growth of plants in wet season followed by drought in dry season
• droughts dry out plant material and make it easier to burn
• winds can cause a fire to grow quickly
• embers can be carried by wind and create new, separate fires