S-290 (WEEK 4)

Question 1

U.1

(True / False) Topography can directly and indirectly affect furls and their availability for combustion.

Answer 1

True

Question 2

U.1

Of the three primary environmental factors that influence fire behavior, which is the least variable?

Answer 2

Geography

Question 3

U.1

The least critical form of heat transfer that influences rate of spread in a running wildland fire is:

Answer 3

Conduction (is the least)

Question 4

U.1

The point to which a combustible material must be heated to produce self sustaining combustion is known as the:

Answer 4

Ignition temperature

Question 5

U.1

Fireline intensity is dependent upon:

Answer 5

1- Fuel size
2- Fuel moisture 
3- Fuel temperature
4- Fuel compactness and arrangement  
***(All Of The Above)***

Question 6

U.1

(True / False) Two requirements for long-range spotting are wind and well developed convection column.

Answer 6

True

Question 7

U.1

A fire that advances through canopies of brush and trees is known as a:

Answer 7

Crown fire

Question 8

U.1
Fire is burning in litter on top of the ground, but occasionally carries into the crowns of individual trees, which produces burning embers that start new fires outside the fire perimeter.

Answer 8

Surface fire with torching and spotting

Question 9

U.1
Fire begins burning into the crowns and spreads through the canopy. There is a sudden increase in fireline intensity where the fire controls its environment. At one point flames can be seen carried high into the convection column with a whirling motion.

Answer 9

Crown fire with convention column and firewhirls

Question 10

U.1
Fire is consuming the organic materials beneath the surface of the ground after the main fire has passed through and is spreading on the surface without flames. Occasionally the fire will ignite areas of unburned fuels on the surface and short fire runs take place.

Answer 10

Ground fire with smoldering and flare ups

Question 11

U.2

(True / False) Upward moving air contracts and warms.

Answer 11

False

Question 12

U.2

As air sinks, it:

Answer 12

Increases in pressure; warms and compresses

Question 13

U.2

Why do dry climates usually have lower nightime temperatures than humid climates?

Answer 13

a

Question 14

U.3 (Attachment)
Using the relative humidity table attached, what is the relative humidity at 1,200’ elevation when the dry bulb temperature is 76F and the wet bulb is 57F?

Answer 14

a

Question 15

U.3 (Attachment)

Using the relative humidity table attached,

Answer 15

a

Question 16

U.3
At 0930hrs, you have the following information; The dry bulb temperature is 65F and wet bulb is 46F. What will the minimum afternoon relative humidity be if the forecast maximum temperature is 83*F and the location is 1200’?

Answer 16

a

Question 17

U.3
(True / False) On the average the relative humidity doubles with each 20* F decreases of temperature, or halves with each 20* F increase in temperature.

Answer 17

True

Question 18

U.3

(True / False) The lowest relative humidity occurs with the highest temperature.

Answer 18

True

Question 19

U.3

(True / False) Relative humidity is usually lower on north aspects.

Answer 19

False

Question 20

U.3

(True / False) Cloudiness has little affect on relative humidity and temperature.

Answer 20

False

Question 21

U.3

(True / False) The type of vegetation has little affect on temperature and humidity.

Answer 21

True

Question 22

U.3

(True / False) Relative humidity measures the amount of moisture in the air.

Answer 22

True

Question 23

U.4

Clouds form in layers.

Answer 23

Stable

Question 24

U.4

Gusty winds.

Answer 24

Unstable

Question 25

U.4 | Smoke Column spreads out after limited rise.

Answer 25

Stable

Question 26

U.4 | Clouds grow vertically.

Answer 26

Unstable

Question 27

U.4 | Firebrands are lifted into convection column.

Answer 27

Unstable

Question 28

U.4 | (True / False) Temperature decreases with an increase in elevation when an inversion is present.

Answer 28

False

Question 29

U.4 | What is the general effect of stable air on wildland fires?

Answer 29

Fire activity decreases

Question 30

U.4 | What conditions will occur under a surface inversion during the morning hours?

Answer 30

1- Temperatures are cool, winds are calm or light 2- Fire activity decreased 3- Pollutants can accumulate under inversions ***(All Of The Above)***

Question 31

U.4 | What are the different lifting processes that can lead to thunderstorm development?

Answer 31

Frontal, orographic, thermal, convergence

Question 32

U.4 | (True / False) Unstable air can often be found in low pressure systems and on the leading edge of cold fronts.

Answer 32

True

Question 33

U.4 | (True / False) Unstable air can be formed by either heating the air near the ground or by cooling the air aloft.

Answer 33

True

Question 34

U.5 | Wind direction is:

Answer 34

The direction the wind is blowing from.

Question 35

U.5 | A slope wind is caused by:

Answer 35

Warm air rising and cold air settling.

Question 36

U.5 | Foehn winds can adversely affect wildland fires because they can produce:

Answer 36

Strong winds

Question 37

U.5 | When stable air is forced over a mountain range, and then descends the leeward slopes as dry, warmed air, it is called:

Answer 37

A foehn wind

Question 38

U.5 | (True / False) Bends in canyons are likely places for wind eddies to form.

Answer 38

True

Question 39

U.5 | Local winds are best defined as:

Answer 39

Small scale

Question 40

U.5 | East, Mono, Santa Ana, and Chinook are all examples of

Answer 40

Foehn Winds

Question 41

U.5 | (True / False) Air flows clockwise around low pressure systems and counterclockwise around high pressure systems.

Answer 41

False

Question 42

U.6 | Slope affects fuel availability to burn because:

Answer 42

Fuels are preheated upslope through radiation and convection; and Rolling firebrands ignite new fuels below ***(Both A and B)****

Question 43

U.6 | Select the correct statement regarding the shape of the country and its effect on wildland fire behavior.

Answer 43

The shape of the country can influence the curing of fuels as well as the intensity and spread of wildland fires.

Question 44

U.6 | Aspect affects fuels and their availability to burn because...

Answer 44

- Southwest slopes provide drier sites - Vegetation type and fuel moisture content changes by aspect - Shading on northern aspects can increase relative humidity * *ALL OF THE ABOVE**

Question 45

U.6 | Select the statement that best describes the effect of slope steepness on fuel availability.

Answer 45

A fire starting at the base of a slope has more fuel available for spread

Question 46

U.7 | A fuel model is defined as....

Answer 46

A set of numbers that define fuel input for use in the surface fire spread model

Question 47

``` U.7 The four (4) fuel groups defined in the fire behavior prediction system (FBPS) are: ```

Answer 47

Grass, shrub, timber, litter and logging slash

Question 48

U.7 | Available fuels are:

Answer 48

All dead and live fuels that will ingnite and continue to burn

Question 49

U.7 | Fuel loading:

Answer 49

The oven-dry weight of fuel in an given area, expressed in tons/acre or pounds/acre.

Question 50

U.7 | Fuel moisture content:

Answer 50

The amount of water in a fuel expressed as a percent of the oven-dry weight of that fuel

Question 51

U.7 | Fuel size and shape:

Answer 51

The surface-area to volume ratio

Question 52

U.7 | Fuel chemical content:

Answer 52

The presence of volatile substances in a fuel

Question 53

U.7 Which of the following fuel characteristics affect all six wildland fire behavior concerns: ie ignition, spread, intensity, spotting, torching, and crowning?

Answer 53

Moisture content

Question 54

U.7 | Which fuel has the higher surface-area-to-volume ration?

Answer 54

GRASS

Question 55

U.7 | The 1-hour timelag fuel category is:

Answer 55

0.0 to 1/4inch in diameter

Question 56

U.8 | Fuel moisture timelag can best be described as:

Answer 56

The rate at which dead fuel gains or loses moisture

Question 57

U.8 | One hour timelag fuel moisture is used in fire behavior calculations to determine:

Answer 57

Whether large fuels are available for ignition and fire spread

Question 58

U.8 | The five stages of vegetation development for live fuel moistures are:

Answer 58

300%, 200%, 100%, 50% and less than 30%

Question 59

U.8 | The following statement best describes timelag fuel categories:

Answer 59

1 hour timelag fuels react to changes in relative humidity much faster than 100 hour fuels

Question 60

U.8 (True / False) Foehn winds always cause fuels to gain in moisture content.

Answer 60

FALSE

Question 61

U.8 (True / False) Dead grass reacts like a 1-hour timelag fuel.

Answer 61

TRUE

Question 62

U.8 | The fuel moisture at which fire will not spread is the:

Answer 62

Moisture of extinction

Question 63

U.8 | Inputs used to determine fine dead fuel moisture content are:

Answer 63

Time of day, month of year, dry bulb temperature, relative humidity, aspect, percent slope, shading of surface fuels

Question 64

U.8 It is September 10, at 1000hours. Fuels are unshaded on an east aspect, 20% slope. Weather observations taken at the site are: Dry bulb temp. 81*F, relative humidity 14%. The fine dead fuel moisture is:

Answer 64

4%

Question 65

U.8 It is Nov. 4 at 1600hours. Fuels are shrub on a west aspect, 35% slope. Weather observations taken at your location are: Dry bulb temp. 68*F. relative humidity 23% and cloud cover shading the fuels. The fine dead fuel moisture 1300 feet below you is:

Answer 65

8%

Question 66

U.8 (True / False) Only the 1000-hour timelag fuel moistrure is used when making wildland fire behavior predictions.

Answer 66

FALSE

Question 67

U.8 | Select the fuel complex that would reach its moisture of extinction first during nighttime humidity recovery.

Answer 67

Cured cheatgrass

Question 68

U.9 | If the wet bulb is not read at its lowest point, what will happen

Answer 68

The calculated relative humidity will be too high

Question 69

U.9 | What weather processes can and should be monitored visually?

Answer 69

- Thunderstorm buildups - Clouds - Approaching cold fronts - Indications of a stable or unstable air ***ALL OF THE ABOVE***

Question 70

U.9 When a cold front or thunderstorms are forecast in the vicinity of a fire, what is the most important information a security weather watch can provide?

Answer 70

Strong shifting winds

Question 71

U.9 The criteria for determining a Red Flag Warning is a combination of high to extreme fire danger and a critical fire weather pattern such as:

Answer 71

- Dry lightning - Lightning following an extremely dry period - Unusually low relative humidity - Very dry and unstable air **ALL OF THE ABOVE**

Question 72

U.9 | Spot weather forecasts are:

Answer 72

Forecasts that are issued to fit the time, topography and weather of a specific location

Question 73

U.10 | Initiate action based on ________ fire behavior.

Answer 73

Current and expected

Question 74

U.10 Fire which can generally be attacked at the head or flanks by persons using hand tools have flame lengths that are _________.

Answer 74

Less than 4 feet

Question 75

U.10 (True / False) Effective windspeed is the midflame increased for the effect of slope on fire spread.

Answer 75

FALSE

Question 76

U.10 | The surface fire characteristic charts relates __________.

Answer 76

Rate of spread and flame length

Question 77

U.10 (True / False) Regardless of fine dead fuel moisture percentage, rate of spread is determined by the live fuel moisture.

Answer 77

FALSE

Question 78

U.10 En route to a fire you notice that smoke from burning haystack rises straight up. What could this indicate on a wildland fire:

Answer 78

An unstable atmosphere may increase fire activity

Question 79

U.10 | A ground fire has burned under a thick stand of pine reproduction. What potential problems could occur?

Answer 79

A reburn possibly involving the canopies

Question 80

U.10 You are on a fire in the coast range of Southern California. The fire is burning above you on the slope. At 1800 hours you experience a sudden calm in the sea breeze. What might you next expect to occur?

Answer 80

Wind may shift to downslope with possible foehn wind surfacing

Question 81

U.10 The convection column from your fire has developed to several thousand feet as a result of intense burning. You notice the top of the column has been sheared off. What could happen next?

Answer 81

B) Expect moderate to long range spotting downwind C) Strong winds aloft could surface on the fire BOTH B and C are CORRECT

Question 82

U.11 | Wildland fire behavior in the third dimension:

Answer 82

- Presents a vertical dimension to fire suppression - Exhibits crowning, spotting and vortex phenomena **ALL OF THE ABOVE**

Question 83

U.11 | Four factors that are responsible for the occurrence of fire behavior in the third dimension are:

Answer 83

Available fuels, wind, high atmospheric moisture and instability

Question 84

U.11 | Three stages of crown fire development are:

Answer 84

1- Passive 2- Active 3- Independent

Question 85

U.11 (True / False) Crown fire development depends on crown flammability along with adequate surface-to-crown and crown-to-crown heat transfer.

Answer 85

TRUE

Question 86

U.11 | The factors that contribute to the spotting problem can be classified into three general areas....

Answer 86

1- Firebrand source 2- Transportation 3- The receiving fuel

Question 87

U.11 | Probability of ignition is determined by:

Answer 87

Fuel shading, fine dead fuel moisture percent and dry bulb temperature

Question 88

U.11 With a fine dead fuel moisture of 8%, a dry bulb temp of 92*F and a cloud cover of 70&, what is the probability of ignition?

Answer 88

40

Question 89

U.11 (True / False) Vortices are grouped as vertical or horizontal depending on their axis of rotation.

Answer 89

TRUE

Question 90

U.11 | When the wildland fire environment is dominated by a ______ fire, the convection column overpowers the wind field.

Answer 90

Plume-dominated

Question 91

U.12 (True / False) Continuous fine fuels, heavy fuel loadings, ladder fuels, crown spacing and special fuel situations are fuel characteristics that should NOT be monitored.

Answer 91

FALSE

Question 92

U.12 (True / False) Low relative humidity and a high 1000 hour timelag fuel moisture are both critical fuel moisture indicators that should be monitored.

Answer 92

FALSE

Question 93

U.12 (True / False) Steep slopes, chutes, saddles and narrow canyons are terrain indicators that should be monitored.

Answer 93

TRUE

Question 94

U.12 (True / False) Strong surface winds, lenticular clouds, high fast moving clouds, approaching cold front, cumulonimbus development and sudden calm or battling winds are all indicators of wind that are not of great concern to wildland firefighters.

Answer 94

FALSE

Question 95

U.12 | Which of the following is an indicator of stable air?

Answer 95

Inversion

Question 96

U.12 | Which is an indicator of possible fire behavior problems?

Answer 96

- Leaning, sheared, or well-developed smoke column - Trees crowning - Firewhirls beginning - Frequent spot fires * **ALL OF THE ABOVE***