Wildland Chapter 4

What terrain indicator causes a channeling effect that can contribute to rapid rates of spread? Select one: a. Saddles b. Shorelines c. Wide valleys d. Steep slopes

Saddles

What happens to plume-driven fires that are accompanied by indrafts? Select one: a. Air dropping from upper atmosphere pushes the fire in all directions. b. A cycle of reinforcement develops, increasing both the intensity of the fire and the wind. c. The drafts hit the ground and the wind spreads in all directions, causing real havoc for firefighters. d. Dry heated air is pushed out in front of the main fireline, rapidly preheating and drying out the fuels.

A cycle of reinforcement develops, increasing both the intensity of the fire and the wind.

In what way will flames with lengths of 4 to 8 feet influence fire suppression tactics? Select one: a. Handlines should be able to easily hold the fire. b. Control efforts at the head of the fire are ineffective. c. Fires are small enough for a direct attack on the head with hand tools. d. Bulldozers, engines, and retardant drops can be effective methods of controlling the fire.

Bulldozers, engines, and retardant drops can be effective methods of controlling the fire.

What type of fuel can set the stage for an intense fire that may burn for a long period of time? Select one: a. Fine, flashy fuels b. Heavy, green fuels c. Dead-and-down fuels d. Spotty patches of dead fuel

Dead-and-down fuels

What danger stems from a plume-dominated fire? Select one: a. Firewhirls b. Crown fires c. Downbursts d. Increased spot fires

Downbursts

What does it mean if trees are beginning to torch either one at a time or in groups? Select one: a. Winds are shifting. b. A cold front is approaching. c. Relative humidity is dropping. d. The fire is about to go vertical.

Relative humidity is dropping.

The presence of ____________ will likely lead to a crown fire. Select one: a. little to no wind b. atmospheric instability c. fine and flashy fuels on the surface d. brush and young trees mixed with taller fuels

brush and young trees mixed with taller fuels

One of the most important topographic components is the: Select one: a. elevation. b. steepness of slope. c. shape of the terrain. d. position on the slope.

steepness of slope.

When you have a wind-driven fire: Select one: a. the rate-of-spread is slow. b. the flanks of the fire may be safe to attack. c. the direction of spread is difficult to predict. d. there will be little to no chance of long-range spotting.

the flanks of the fire may be safe to attack.

Live fuel moisture is a factor affecting the possibility of crown fires and is controlled by: Select one: a. the stage of growth, which is related to the time of year. b. the time of day, which generally affects the relative humidity. c. whether the young trees and brush are deciduous or coniferous. d. the compactness of the fuel, and its relative position to finer fuels.

the stage of growth, which is related to the time of year.

In order for fuel to ignite, the ignition source must first heat the fuels: Select one: a. to the point of ignition. b. well past the point of ignition. c. using a convective heat source. d. using self-sustaining combustion.

to the point of ignition.

What term means "fire burning on the surface, but periodically igniting the crown of a single or small group of trees or shrubs before returning to the surface?" Select one: a. Blowup b. Spotting c. Torching d. Crowning

torching

What is the short term effect of increasing temperature that leads to increased fire behavior? Select one: a. Local winds decrease b. Relative humidity increases c. Fuel temperature decreases d. Atmospheric instability increases

Atmospheric instability increases

What is an environmental factor that contributes to extreme fire behavior? Select one: a. Available fuel b. Stable air mass c. Inversion layers d. High atmospheric moisture content

Available fuel

During what time of day can a fire most easily be controlled? Select one: a. 0600 to 1000 hours b. 1800 to 0400 hours c. 1000 to 1800 hours d. 0400 to 0600 hours

0400 to 0600 hours

During what time of day are all factors of fire intensity at their highest? Select one: a. 0600 to 1000 hours b. 0400 to 0600 hours c. 1800 to 0400 hours d. 1000 to 1800 hours

1000 to 1800 hours

What type of crown spacing will permit convective and radiant heat transfer to occur at a level of intensity that can maintain a fire spreading through the crowns? Select one: a. 5 feet or less, roughly 400 trees per acre b. 100 feet or less, roughly 20 trees per acre c. 20 feet or less, roughly 100 trees per acre d. 1 foot or less, roughly 2,000 trees per acre

20 feet or less, roughly 100 trees per acre

Combustion usually occurs at about _____ degrees Fahrenheit in wildland fuels. Select one: a. 900 b. 100 c. 212 d. 500

500

What accurately describes a horizontal vortex? Select one: a. The smoke (convection) column is pushed over by the wind, driving the heat into the unburned fuels. b. Indrafts provide oxygen to the fire and preheat the fuel, which in turn feeds the fire, creating even more indrafts. c. When unstable air begins to rotate as hot and cold air pass by each other, this vortex can pick up embers and push hot air in all directions. d. A fire burns so hot that the rising smoke rotates and if a strong wind is present, it can force the rotating vortex over, horizontal to the terrain.

A fire burns so hot that the rising smoke rotates and if a strong wind is present, it can force the rotating vortex over, horizontal to the terrain.

Which statement about surface fire intensity is accurate? Select one: a. If the intensity of the fire increases, the rate at which a fuel is preheated decreases. b. If the fuel contains resins, oils, or waxes, this can reduce the energy output of the fire, slowing the rate of spread. c. A small portion of energy released during combustion, usually less than 20%, is effective in heating unburned fuels. d. The relationship between the flame zone and unburned fuel is changed in the same way by a 75% slope or a 2 MPH wind.

A small portion of energy released during combustion, usually less than 20%, is effective in heating unburned fuels.

What is indicated by a well developed smoke column? Select one: a. Potential for long-range spotting and strong surface winds b. Conditions are changing and the fire behavior is going to pick up c. A wind-driven fire, one with a rapid rate of spread and short-range spotting d. Can expect intense burning conditions and unpredictable fire spread in all directions

Can expect intense burning conditions and unpredictable fire spread in all directions

What is indicated by smoldering fires that begin to pick up? Select one: a. Changing weather factors b. Long-range spotting will pick up c. Unpredictable fire spread in any direction d. Moving from a surface fire to a crown fire

Changing weather factors

How does convective heating contribute to spotting? Select one: a. The main fire burns away material, dislodging burning fuel that then falls into unburned fuel. b. Strong winds will push heated air ahead of the fireline and ignite fuels ahead of the main fire. c. Firebrands are lifted by the convective heating and dropped some distance ahead of the main fire. d. Heat produced by the fire lifts very light fuels like grasses across the fireline and they ignite as they reach the ground.

Firebrands are lifted by the convective heating and dropped some distance ahead of the main fire.

What factor will accurately determine the probability of spotting? Select one: a. Firebrands that are dense and round will travel great distances and start spot fires. b. Cover canopy promotes the upward travel of firebrands and intensifies the spotting problem. c. The hotter the fire, the more thoroughly fuel will burn, thus reducing the amount of firebrands. d. Firebrands must land on receptive fuels, such as litter, duff, and rotten wood, in order for them to ignite.

Firebrands must land on receptive fuels, such as litter, duff, and rotten wood, in order for them to ignite.

How is fire intensity of a wildland fire measured? Select one: a. Potential and actual fuel load b. Area engulfed and fuel density c. Fuel density and rate of spread d. Fireline intensity and flame length

Fireline intensity and flame length

What accurately describes how fire intensity can be affected? Select one: a. The type but not the amount of fuel available to burn can influence intensity. b. Fires burn more intensely moving upslope or downwind, because convective heating is more efficient. c. If the fuels are tightly arranged, with little space for air or convective heat to move, the fire will be more intense. d. If a considerable amount of heat is needed to decrease the fuel moisture content sufficiently to allow for combustion, the fire will burn with more intensity.

Fires burn more intensely moving upslope or downwind, because convective heating is more efficient.

What fire behavior indicator signals that the fire has the potential to move from a surface fire to a crown fire? Select one: a. Firewhirls b. Frequent spot fires c. Sheared smoke columns d. Smoldering fire is picking up

Firewhirls

What is a good indicator that 1,000-hour fuels will burn? Select one: a. Fuel moisture is 20% or less. b. They break easily when bent. c. Relative humidity is 25% or less. d. Finer fuels have already dried out.

Fuel moisture is 20% or less.

How can thunderstorms have a particularly dangerous impact on fire behavior? Select one: a. It can bring in large masses of cool, wet air. b. It can create downdrafts that push fire in all directions. c. It will bring foehn winds that will quickly dry out the fuel. d. It will bring vertical shafts of air that lift fire brands up and deposit them over long distances.

It can create downdrafts that push fire in all directions.

What is a characteristic of a passive crown fire? Select one: a. The crown fire will run ahead of the surface fire. b. The fire is not dependent on the surface fire for energy. c. Although crowns of trees may fully burn, spotting rarely occurs. d. It is entirely at the mercy of a surface fire and the availability of ladder fuels.

It is entirely at the mercy of a surface fire and the availability of ladder fuels.

What is a characteristic of short-range spotting? Select one: a. It is spotting that is quickly overrun by the main front of a fire. b. It includes spotting that occurs in directions other than downwind. c. It may contribute to the spread of the fire, but in the same way a new fire would. d. It occurs only from falling fuels, popping fuels, or any other movement that does not involve convective columns of heat.

It is spotting that is quickly overrun by the main front of a fire.

What is the most direct way that wind influences the fire's direction of spread? Select one: a. It dries out fuel, making ignition easier. b. It brings the fuel closer to the heat source. c. It feeds the fire by providing more oxygen to the fire. d. It pushes or bends the fire, bringing the radiated and convective energy closer to the fuel bed.

It pushes or bends the fire, bringing the radiated and convective energy closer to the fuel bed.

For an active or independent crown fire to sustain its run, what conditions are needed? Select one: a. High fuel moisture b. Low fuel moisture and steep slopes c. Strong winds and ample crown spacing d. Low surface fire intensity and steep slopes

Low fuel moisture and steep slopes

What type of fire and wind conditions lead to rapid spread both up and downslope with frequent spotting and area ignition? Select one: a. Towering convection column over slope b. Mountain topography with strong surface winds c. Strong convection column with strong surface winds d. Towering convection column with light surface winds

Mountain topography with strong surface winds

What type of spotting is a mechanical event that throws a burning piece of wood away from the fire only a short distance? Select one: a. Winds b. Gravity c. Popping d. Convection

Popping

When does area ignition occur? Select one: a. Fire behavior becomes so intense that it pulls air towards it and lifts several firebrands great heights into the air. b. Winds drive a fire forward at great speed, pushing firebrands forward and off to the sides of the head of the fire. c. Long-range spotting occurs in directions other than downwind, leading spot fires to burn along the flanks of the fireline. d. Spot fires begin to draw each other closer, connecting their convective actions, which may result in the area exploding in fire.

Spot fires begin to draw each other closer, connecting their convective actions, which may result in the area exploding in fire.

What do lenticular clouds indicate? Select one: a. Precipitation b. Atmospheric stability c. Strong winds at high elevations d. Shifts in the direction of surface winds

Strong winds at high elevations

What factor affects the ignition of wildland fuels? Select one: a. The drier the fuel, the easier it is to ignite. b. The colder the fuel, the easier the fuel will be to ignite. c. If the fuels are close and tightly packed, they will ignite more easily. d. The smaller or finer the fuels are, the more difficult they are to ignite.

The drier the fuel, the easier it is to ignite.

What does "spread" mean, in the context of fire behavior? Select one: a. The distance that a fire has traveled from ignition b. The movement of fire, usually measured by time and distance c. The measure of heat created by the fire expressed in rate of spread d. The direction in which the fire is moving at the greatest rate of spread

The movement of fire, usually measured by time and distance

In what way can a fire's rate of spread be influenced? Select one: a. If the fire intensity decreases, the heat generation and rate of spread increases. b. If the fire does not generate spot fires ahead of or below the fire, the burn pattern will be affected. c. If the fuels are loosely arranged, with plenty of space for air or convective heat to move, the fire will be less intense. d. The stronger the wind, the more lean it puts on the flame and the convection column, and the faster the rate of spread.

The stronger the wind, the more lean it puts on the flame and the convection column, and the faster the rate of spread.

What is a characteristic of independent crown fires? Select one: a. It is dependent on the surface fire for humidity. b. The surface fire spread is the result of the crown fire. c. The crown fire requires energy from surface fires below. d. The greatest danger is its potential for localized spotting.

The surface fire spread is the result of the crown fire.

What is particularly dangerous about a low-intensity fire that has moved through the area burning the understory? Select one: a. The upper-level fuels have been dried out and can burn with extreme intensity. b. The ground fuels can retain heat for a long time and can easily cause a rekindle. c. It will produce snags and widow makers that can be dangerous long after the fire is out. d. This type of fire produces large amounts of firebrands that can quickly create an enormous number of spot fires.

The upper-level fuels have been dried out and can burn with extreme intensity.

What makes fuels such as chamise, jack pine, and palmetto/gallberry more susceptible to crown fires? Select one: a. They contain volatile oils. b. They are shorter trees with lower hanging branches. c. They tend to have a very high ratio of dead to live fuels. d. They grow in dry climates that keeps their live fuel moisture low.

They contain volatile oils.

How do foehn or gravity winds affect fire behavior? Select one: a. They push heated and dry air over mountain ranges. b. They push fire up slopes, dramatically increasing the rate of spread. c. They have a chimney effect that channels fire in unpredictable directions. d. They produce downdrafts that push the fire in several different directions.

They push heated and dry air over mountain ranges.

What statement regarding weather-related factors that influence fire behavior is accurate? Select one: a. Atmospheric stability and wind speed do not vary. b. Weather can vary as air masses move through an area. c. Weather is the most consistent component of the fire environment. d. The current temperature of an area has little effect on fire behavior.

Weather can vary as air masses move through an area.

A wildland fire will burn in predictable elliptical patterns when what factor is the only variable? Select one: a. Wind b. Slope c. Fuel density d. Fire intensity

Wind

Why should approaching cold fronts be concerning? Select one: a. A tornado will follow. b. Air will rapidly become dry. c. Strong downdrafts will develop. d. Winds will shift and change speed.

Winds will shift and change speed.

What is a signal that downdrafts may be developing in plume-driven fires? Select one: a. You begin to see virga and/or rain. b. Indrafts begin to increase fire intensity. c. Long-range spotting begins to start additional fires. d. The smoke column is pushed over by the wind, driving the heat into the unburned fuels.

You begin to see virga and/or rain.

What is a characteristic of wind-driven fires? Select one: a. Spotting occurs in all directions. b. Crown fires are not likely to develop. c. You usually have an idea what direction it will burn in. d. A well developed smoke column will move straight up.

You usually have an idea what direction it will burn in.

"Creeping" is understood to mean fire that is: Select one: a. burning with low flame and spreading slowly. b. burning without flame and spreading very slowly. c. moving away from the head, downhill, or against the wind. d. burning on the surface, but periodically igniting the crown of a single tree or shrub or small group of trees or shrubs before returning to the surface.

burning with low flame and spreading slowly.

There are three factors that influence the direction a fire will burn: wind, slope, and: Select one: a. time of day. b. relative humidity. c. condition of the fuel. d. atmospheric temperature.

condition of the fuel.

Whenever you have a plume-driven fire: Select one: a. the direction of spread is predictable. b. wind shifts should be a major concern. c. downdrafts should be a major concern. d. spotting occurs in a consistent direction.

downdrafts should be a major concern.

When an inversion layer is present,: Select one: a. fire behavior below it will normally be subdued. b. the atmosphere is considered to be very unstable. c. fire behavior can be unpredictable within the cold air below. d. fire is likely to quickly jump from one side of the layer to the other.

fire behavior below it will normally be subdued.

Compactness, horizontal continuity, and chemical content are aspects of _____ components that affect fire behavior. Select one: a. fuel b. weather c. atmospheric d. topographical

fuel