what dictates fire behavior the fire behavior triangle why do ecologists care n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
What dictates fire behavior–the fire behavior triangle. Why do ecologists care? PowerPoint Presentation
Download Presentation
What dictates fire behavior–the fire behavior triangle. Why do ecologists care?

Loading in 2 Seconds...

play fullscreen
1 / 34

What dictates fire behavior–the fire behavior triangle. Why do ecologists care? - PowerPoint PPT Presentation


  • 205 Views
  • Uploaded on

What dictates fire behavior–the fire behavior triangle. Why do ecologists care? . 1. Weather 2. Fuels 3. Topography. Fire behavior largely determines fire effects!. Fuel Types- 4 Categories: where it is located.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

What dictates fire behavior–the fire behavior triangle. Why do ecologists care?


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
    Presentation Transcript
    1. What dictates fire behavior–the fire behavior triangle. Why do ecologists care? 1. Weather 2. Fuels 3. Topography Fire behavior largely determines fire effects!

    2. Fuel Types- 4 Categories: where it is located Fire behavior is largely determined by which fuel strata is carrying the fire: • Ground • Surface • Ladder • Crown/ aerial

    3. Fuel Types • Ground Fuels • Duff (partially decomposed) • Peat • Roots • Stumps litter fermentation layer Duff humus mineral soil

    4. Fuel Types • Surface Fuels • Grasses • Shrubs • Litter (leaves) • Woody debris

    5. SURFACE AND GROUND FUELS

    6. Fuels • Aerial/ canopy Fuels • Crown or canopy of overstory • Ladder Fuels (located between crown and surface fuels) • Smaller trees • Vines

    7. For each fire type: Fuel Characteristics influence fire behavior • Fuel Loading • Size and shape • Compaction • Chemistry • Arrangement • Vertical • Composition • Continuity • horizontal

    8. Fuel Loading

    9. Fuel loading- do we just weigh everything that can burn? • Fuel loading is simplified by categorizing fuels into similar groups • All fuels are characterized by their size category, called “timelag fuel class”. This is related to their capacity to absorb and lose water in relation to their environment. • The most important factor associated with fuel size is its surface area to volume ratio…why?

    10. Timelag Fuel Class • EMC = equilibrium moisture content: the watever vapor pressure of the fuel is in equilibrium with the wvp of air. • Given a stable air mass, the “timelag” is time it takes for a particle of fuel to reach 63% of the difference between its initial moisture content and the equilibrium moisture content. • It is NOT how long the fuel will burn

    11. Timelag= approaching equilibrium • It takes 5 timelags for 95% of the change to occur • But most of the change happens within the first timelag Difference http://stream2.cma.gov.cn/pub/comet/FireWeather/S290Unit10FuelMoisture/comet/fire/s290/unit10/print.htm#page_2.2.0

    12. Larger fuels lose and absorb water less quickly http://stream2.cma.gov.cn/pub/comet/FireWeather/S290Unit10FuelMoisture/comet/fire/s290/unit10/print.htm#page_2.2.0

    13. Timelag categories (know these!) • Size of fuel (diameter, inched) Timelag Class • 0” to ¼” 1 hour • ¼” to 1” 1o hour • 1” to 3” 100 hour • > 3” 1000 hour

    14. Three ways to assess fuel loading • Fuel models • Photo series • Measure it

    15. Fuel Loading – what do you include? Timber Brush

    16. Fuel models use 4 fuel groupings- based on proportion in each timelag class Anderson, 1982 Fuel Models and Fire Behavior Prediction

    17. The 13 fuel models

    18. Example BEHAVE outputs: Rate of spread Rate of Spread for Fuel models at 5 mph wind

    19. FUEL MODEL 13: HEAVY LOGGING SLASH

    20. 6-10 tons/ acre FUEL MODEL 7: SOUTHERN ROUGH

    21. 3-5 tons/acre FUEL MODEL 8: CLOSED TIMBER LITTER

    22. 1-3 tons/acre FUEL MODEL 3: TALL GRASS

    23. Photo series • Hundreds of field plots measured= averaged = photo series fuel loading values. • Digital photo series (USFS) • http://depts.washington.edu/nwfire/dps/

    24. MEASURE IT: Today’s Lab! • Brown’s Planar Intercept