Chapter 5 Fire Environment : Topography & Continued Flashcards

1
Q

Topography is the most ___ of the three major components of the fire environment.

A

constant

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2
Q

The most important factor under topography is ____, since changes in slope have very direct and profound effects on fire behavior.

A

steepness of slope

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3
Q

The position of a slope is important because this ____ and their availability.

A

influences the types and loading of fuels

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4
Q

____ and ___ facing slopes typically have the greatest number of fires.

A

South / west

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5
Q

The fuels on south and west facing slopes cure out earlier in the year, they are typically ____, and the average relative humidity is ____.

A

smaller and drier / lowest on these slopes

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6
Q

These slopes have the ___ fire season and have more light, flashy fuels in which to carry fire on sunny days, south and west facing slopes receive the _____ because of exposure to the sun.

A

longest / longest heat period

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7
Q

North slopes, on the other hand, typically have the ____, highest fuel moisture, lowest average temperature, _____..

A

heaviest fuels / lowest rate of spread of fires and lowest fire starts

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8
Q

The third component of the fire environment is the ____. Fuels are the part of the environment that actually ____. The other two components, weather and topography, determine_____.

A

fuels / carry the fire / how the fuels will burn

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9
Q

Grasses and weeds are

A

(Light Fuels)

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10
Q

Coastal sage scrub are

A

(Moderate Fuels)

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11
Q

Mixed chaparral are

A

(Heavy Fuels)

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12
Q

The moisture content of dead fuels varies from around _____ depending on weather conditions.

A

2% to about 30%,

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13
Q

Dead branches and twigs frequently make up _____ volume in chaparral stands more than 30 years old.

A

one-third to one-half of the fuel

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14
Q

As a rule of thumb, chaparral stands accumulate about ___ dead material for each year since the brush canopy closed following the last major fire or other clearing.

A

1%

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15
Q

____ is generally considered the most important influence on flammability of fuels.

A

Moisture content

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16
Q

The moisture content is highest (_____) in late Winter and early Spring when the vegetation is in its active growing cycle.

A

200% or more

17
Q

Moisture content in living, native vegetation is lowest (_____) in the Fall and early Winter. This is also the time of year when the Santa Ana winds are most prevalent.

A

50-60%

18
Q

_____ compose a high percentage of the fuels in the City of Los Angeles.

A

Grasses and weeds

19
Q

Grasses and weeds are light fuels and compose what we call _____.

A

“flash fuels.”

20
Q

Coastal sage scrub is a plant community made up of _____. Common species include California Sagebrush, Buckwheat, Black Sage, Chamise, Elderberry and Honeysuckle.

A

mainly non-woody brush species

21
Q

______ in the City of Los Angeles occur in this type of fuel complex. This is due to the high ratio of dead material build-up, and the high concentration of volatile chemicals and resins in coastal sage scrub.

A

Most of the brush fires

22
Q

Although coastal sage scrub only grows about ____ in height, fires burn with great intensity, and high rates of spread of fires can be expected.

A

four feet

23
Q

Mixed chaparral makes up the taller (_____) brush found mostly on ____ slopes. Common species include Toyon, Walnut, Scrub Oak, Ceanothus, Manzanita and Catalina Cherry.

A

up to 20 feet / north facing

24
Q

The majority of these 20 inputs are gathered from _____ and from the Riverside National Weather Service.

A

Fire Station 108’s weather station

25
Q

This a 10 hour fuel moisture reading which is acquired from Fire Station 108’s weather station. The weather station has the capability to detect this reading from the weighing of ______.

A

standard array of 1/2” Ponderosa Pines fuel sticks.

26
Q

Our number rating is (2) which calculates to a ___ slope class.

A

26%-40%

27
Q

BRUSH BURNING behavior INDEX is

A

BBI

28
Q

1 Hour Timelag Fuel Moisture : Fuels consisting of dead herbaceous plants and roundwood less than ____ in diameter. Also included is the uppermost layer of litter on the forest floor.

A

one-fourth inch

29
Q

10 Hour Timelag Fuel Moisture :
Fuels consisting of dead twigs, branches and roundwood ____ in diameter, and litter from surface level to _____ on the forest floor.

A

one-fourth to one inch / three-quarters of an inch deep

30
Q

100 Hour Timelag Fuel Moisture :

Dead fuels consisting of roundwood in the size range of _____ in diameter

A

1 to 3 inches

31
Q

1000 Hour Timelag Fuel Moisture :

Dead fuels consisting of roundwood ____ in diameter or the layer of the forest floor from ____ below the surface.

A

3 to 8 inches / three-fourths inch to 4 inches

32
Q

X 1000 Hour Timelag Fuel Moisture :

Dead fuels consisting of roundwood greater than ____ in diameter.

A

8 inches

33
Q

Red Flag :

A

wind speed 25+ and Relative humidity 15% or lower