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
,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
,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
, 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
4
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
,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
,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
, 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
4
