The document discusses the factors that influence fire behavior: the fire triangle of fuel, heat, and oxygen; fuel characteristics like type, size, arrangement, and moisture content; weather factors like temperature, humidity, wind, and precipitation; and topography. It provides definitions and explanations of different types of fire behavior like creeping, torching, and crowning fires, and parts of a fire like the head and flanks.

1. L. C. P. B. - Module 3 Fire Behavior

2. The Fire Triangle Fire Behaviour Overhead FUEL HEAT AIR These 3 Components All Must Be Present to Have Fire: 1 of 31 Low Complexity Prescribed Burn Worker

3. Fire Behaviour Is Described in the Following Terms: Creeping

4. Fire Behaviour Smouldering Is Described in the Following Terms: 2 of 31 Low Complexity Prescribed Burn Worker

5. Fire Behaviour Running Is Described in the Following Terms (cont’d) :

6. Fire Behaviour Torching Is Described in the Following Terms (cont’d) :

7. Fire Behaviour Is Described in the Following Terms (cont’d) : Crowning

8. Fire Behaviour Is Described in the Following Terms (cont’d) : Spotting

9. Combustion Gaseous Vapours Released Raised to ignition Temperature Preheating Flaming ‘ The conversion of living & dead fuels into carbon dioxide, water vapour & heat energy (flame )’ Three Phases: Gaseous Vapours Ignited

10. Combustion Flaming Glowing Three Phases: Gaseous Vapours Ignited Charcoal or solid phase

11. Heat Transfer ‘ Heat energy is transmitted from burning to unburned fuels’ Convection Movement of masses of hot air (can cause spot fires)

12. Heat Transfer ‘ Heat energy is transmitted from burning to unburned fuels’ Conduction Radiation Through solid matter In straight lines from warm surfaces to cooler surfaces

15. Fuel Quantity/Type Crown – ‘standing & supported forest combustibles not in direct contact with surface fuels’ Crown Surface Sub- Surface Duff layer Ladder Fuel

16. Fuel Quantity/Type Surface - ‘all combustible material lying above the duff layer between the ground and ladder fuels’ Crown Surface Sub- Surface Duff layer Subsurface - ‘all combustible material below the litter (duff) layer of the forest floor (e.g., roots, punky wood and peat)’ Ladder Fuel 8 of 31 Low Complexity Prescribed Burn Worker

17. Fuel Quantity/Type Subsurface - ‘all combustible material below the litter (duff) layer of the forest floor (e.g., roots, punky wood and peat)’ Crown Surface Sub- Surface Duff layer Ladder Fuel 8 of 31 Low Complexity Prescribed Burn Worker

22. Fuel Arrangement Spread! ‘ Horizontal & vertical distribution within a particular fuel type’ 11 of 31 Low Complexity Prescribed Burn Worker Laddered Fuels Vertical Continuity between surface fuels and crown fuels Slash Debris left as a result of forestry practices

23. Fuel Arrangement ‘ When considering fuel arrangement, there are 2 situations to be aware of’ …. Slash Debris left as a result of forestry practices Intensity! Laddered Fuels Vertical Continuity between surface fuels and crown fuels Spread!

24. Fuel Distribution ‘ Continuity of fuels over an area’ Continuity can be broken by a natural or constructed barrier or a different fuel type 12 of 31 Low Complexity Prescribed Burn Worker

25. 3 Types of Fires Crown Surface Sub- Surface Duff layer 13 of 31 Low Complexity Prescribed Burn Worker

26. Combustion Flames: Flame Length Flame Height Flame Depth ‘ The visible bi-products of combustion’ Duff Layer Mineral Soil Depth of Burn Direction of spread 14 of 31 Low Complexity Prescribed Burn Worker

28. Parts of a Fire Spot Bay Head Back Flank Flank Finger Fire Perimeter 16 of 31 Low Complexity Prescribed Burn Worker

32. Effects of Weather (cont’d) Defined as the degree of hotness or coldness of a substance High temperature contributes to the drying of forest fuels When temperature is increased, less heat from the fire is required during pre-heating (pyrolisis) stage Temperature

33. Effects of Weather (cont’d) Defined as the natural movement of air parallel to the earth’s surface Can influence fire behaviour by: – moving moist air away from or over fuels – blowing burning embers outside the fire perimeter – carrying burning embers that have been lifted above the ground by convection (may start new fires some distance away) – bending convection columns closer to unburned fuels which will pre-heat them – bringing a continuous flow of oxygen to the fire Wind

34. Effects of Topography SOUTH NORTH SLOPE – Upward or downward slant of the earth’s surface ASPECT – Direction the slope is facing This slope has a ‘Southern Aspect’ ‘ Topography is a description of the physical features of the earth’s surface’ 22 of 31 Low Complexity Prescribed Burn Worker

35. Effects of Topography (cont’d) Convection Column is far from unburned fuels. Convection Column touches unburned uphill fuels. Radiant heat from flame front preheats uphill fuels. 23 of 31 Low Complexity Prescribed Burn Worker Wind

36. Effects of Topography (cont’d) Physical Barriers - ridges, escarpments,hills, mountains, etc. Can have a profound effect on local wind speed and direction Firefighters must deal with local winds The larger the barrier, the more significant the impact Effects of physical barriers on local winds are described as: – barrier effects – channeling – funneling Can result in upslope winds or downslope winds (dependent on time of day)