Fire in the Field Unit 2
When is relative humidity usually at its minimum? Early morning Mid-day Afternoon Sunset Late evening
Afternoon
Factors of topography that can influence fire ignition and spread include Steepness of slope and slope aspect Elevation Position of fire on slope Shape of terrain and barriers All of the above
All of the above
Fuel factors that affect the start and spread of wildland fire include Fuel type Fuel loading Fuel availability All of the above B and A only
All of the above
Fuel indicators that might indicate extreme fire behavior include Unusually dry fuels or fuels exposed to direct sunlight A large amount of continuous light fuels A concentration of snags and/or crown foliage dried by surface fire over a large area Ladder fuels that will allow a surface fire to move into the crowns of brush or trees All of the above
All of the above
Hazards of a thunderstorm include Strong winds Lightning Erratic fire behavior All of the above
All of the above
Some indicators of extreme fire behavior include A bent smoke column or a change in the direction of the smoke column Firewhirls or dust devils The breaking up of an inversion or smoldering fires over a large area becoming more intense All of the above A and B only
All of the above
The weather factors that may produce rapid fire spread include Thunderstorms and cold fronts Slope winds, including foehn winds Strong winds and/or whirlwinds All of the above B and C only
All of the above
Weather indicators that may indicate possible fire spotting include Strong, gusty downdraft winds from thunderstorms Strong, shifting winds from a cold front passage Firewhirls and dust devils All of the above A and B only
All of the above
Weather indicators that might indicate extreme fire behavior include Strong winds or sudden changes in wind direction or velocity due to fronts Thunderstorms that may cause gusty downdraft winds Unusually high temperatures and low relative humidity All of the above A and B only
All of the above
Wind affects fire spread by Increasing the supply of oxygen Influencing the direction of the fire Causing spotting Drying fuels, making them more flammable All of the above
All of the above
Topography indicators that might indicate extreme fire behavior include Natural barriers such as lakes, rivers, and rock outcroppings Chutes, saddles, and box canyons that provide the conditions for the "chimney effect" Steep slopes that allow fire to spread upslope and narrow canyons that increase the possibility of spotting All of the above B and C only
B and C only
______________ is an example of a barrier A pine plantation A road The fireline B and C only
B and C only
To control a fire, we must "break the triangle" or Remove the hydrogen Remove the carbon dioxide Limit or eliminate any side of the triangle Remove the fuel, the oxygen, or the heat source Both C and D are correct
Both C and D are correct
The three ways heat can transfer to fuel are Convection, radiation, conduction Radiation, moisture exchange, convection Crowning, convection, conduction Springing, crowning, peaking None of the above
Convection, radiation, conduction
As relative humidity decreases, fuel moistures Increase Decrease
Decrease
As the cold front passes, which side of a fire is threatened most? N to NE E to SE
E to SE
A north facing slope aspect will have more fire activity than a south facing slope aspect. True False
False
Box canyons cause fairly safe fire conditions because they tend to smother the flames. True False
False
Two types of horizontal arrangement of fuels are topical and sub-surface. True False
False (horizontal are patchy or uniform)
The rate at which dead fuel gains or loses moisture is called Light fuels Ladder fuels Surface fuels Fuel timelag
Fuel timelag
The vertical arrangement of ladder fuels describes what? Fuels that link surface materials to the upper canopy. The fuels lying beneath the surface. Fuels lying on or above the ground. All green and dead materials located in the upper canopy.
Fuels that link surface materials to the upper canopy.
Look at the picture and choose the type fuel that best describes what you see. Grass Shrub Timber litter Logging slash
Grass
The fire triangle represents the three elements needed for fire to exist, which are Fuel, water, and oxygen Heat, carbon dioxide, and fuel Heat, fuel, and oxygen Hydrogen, oxygen, and heat None of the above
Heat, fuel, and oxygen
Look at the picture and choose the type fuel that best describes what you see. Light fuel Heavy fuel
Heavy fuel
Look at the picture and choose the type fuel that best describes what you see. Light fuel Heavy fuel
Light fuel
Which type of fuel is most affected by a change in relative humidity? Heavy fuels Light fuels
Light fuels
Look at the picture and choose the type fuel that best describes what you see. Grass Shrub Timber litter Logging slash
Logging slash
As a cold front approaches from the northwest, which side of a fire is threatened most? NW to NE SW to SE
NW to NE
Look at the picture and choose the type fuel that best describes what you see. Uniform fuels Patchy fuels
Patchy fuels
As wildland firefighters, the heat transfer methods we are most concerned with are Conduction and convection Crowning and peaking Springing and crowning Radiation and convection Radiation and conduction
Radiation and convection
Look at the picture and choose the type fuel that best describes what you see. Grass Shrub Timber litter Logging slash
Shrub
All combustible materials lying on or immediately above the ground are called Light fuels Ladder fuels Surface fuels Fuel timelag
Surface fuels
Look at the picture and choose the type fuel that best describes what you see. Grass Shrub Timber litter Logging slash
Timber litter
It is more difficult to predict fire behavior based on weather, since it is more subject to change than topography, which is more constant. True False
True
Narrow canyons may cause dangerous fire conditions because heat radiation could easily ignite the fuel on the opposite side. True False
True
On the south aspect of a slope, the mid-afternoon slope winds tend to be strong upslope winds, but at midnight they are most often light, downslope winds. True False
True
Relative humidity, precipitation, and wind can all affect fuel moisture. True False
True
The National Weather Service (NWS) issues Fire Weather Planning Forecasts (FWF) as well as fire weather watches and red flag warnings. True False
True
The steeper the slope, the faster the fire spreads uphill. True False
True
Three principal environmental elements that affect fire behavior are fuel, weather, and topography. True False
True
Wind is one of the most important influences on fire behavior. True False
True
Look at the picture and choose the type fuel that best describes what you see. Uniform fuels Patchy fuels
Uniform fuels
