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S-190 Intro to Wildland Fire Behavior Questions and Answers Latest Update Graded A+
What is the primary factor that influences how fast a wildfire spreads?✔✔ Wind speed
What part of a fire is usually the hottest and most intense?✔✔ The head of the fire
What is the term for unburned fuel between the head and the heel of a wildfire?✔✔ The flanks
What are the three components of the fire triangle?✔✔ Heat, fuel, and oxygen
What is a fire’s “rate of spread”?✔✔ The speed at which a fire moves in a given direction 1 / 4
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Why is slope important in wildland fire behavior?✔✔ Fires burn faster uphill due to preheating of fuels above
What is the most common cause of sudden changes in fire direction or intensity?✔✔ Shifting wind
What does spotting refer to in wildfire behavior?✔✔ Embers carried by wind start new fires ahead of the main fire
What is the term for air movement created by the fire itself?✔✔ Fire-induced wind
What is the term for the direction a fire is naturally moving?✔✔ Direction of maximum spread
What are the four fuel types in wildland fire behavior?✔✔ Grass, brush, timber, and slash 2 / 4
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What does “fuel moisture” refer to in fire behavior?✔✔ The amount of water contained in vegetation
What happens to fire behavior as fuel moisture decreases?✔✔ Fire spreads more quickly and intensely
What type of fuel tends to ignite and burn the fastest?✔✔ Fine fuels like grasses and twigs
What is one weather condition that increases the risk of extreme fire behavior?✔✔ Low relative humidity
Why are afternoon hours often the most dangerous for fire activity?✔✔ Temperatures are highest and humidity is lowest
What is a “fire whirl”?✔✔ A spinning vortex of flame and ash caused by intense heat and wind 3 / 4
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What is the term for a fire that burns through the canopy of trees?✔✔ Crown fire
What is the name for the area where the fire started?✔✔ Point of origin
What is the backing part of a wildfire?✔✔ The side of the fire moving against the wind or downhill
What type of topography can funnel and intensify fire behavior?✔✔ Canyons and narrow drainages
What effect does dense vegetation have on fire behavior?✔✔ Provides more fuel, increasing fire intensity
What time of day do fires usually calm down?✔✔ Early morning or late evening
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