Wildland Handbook Flashcards
The A in LACES stands for what?
Awareness
Give snags what percent margin uphill and downhill?
50 and 150 downhill
Never work within how many ft of a high voltage tower or pole structure
35 ft
The weather factors that can effect the start and spread of a woodland fire are what?
Wind
Humidity
Temp
Precipitation
The layer of atmosphere closest to the ground is called the what?
Troposphere
An approaching cold front is an indication of what?
Wind
Wind speed is determined by what?
The pressure gradient
Typical cold front wind speeds range from what to what?
10 to 30 mph
Santa Ana chinook and mono are local names for what?
Fohen winds
Downburst are caused by what collapsing?
Thunderstorms
What is an indicator that a thunderstorm has matured and downdraft winds may be in the future?
Virgo
If the rh is at _ percent or lower fires will burn freely?
30
If rh is at_ percent or below, the fire danger is critical and extreme fire behavior is possible?
10
For every 20 degree increase in temperature the rh drops by how much?
One half
The presence of an inversion later indicates what?
The air is very stable.
Cumulus and cumulonimbus are clouds that have bases at what height?
1500 to 10,000 ft
What are middle level clouds with a base between 6500 and 20,000 ft?
Alto clouds
What are low level clouds with a base at or below 6,500 ft?
Strato clouds
What are high clouds with a base of 20,000 ft?
Cirro clouds
The three principal environmental elements affecting wildland fires are what?
Fuel
Weather
Topography
On a moderate slope of 30% rate of spread is increased by a factor of what?
2
On steep slopes of what percent the rate of spread will again double?
55%
What is the name for the direction a slope is facing?
Aspect
When will south and west facing slopes normally burn hotter?
Afternoon
What aspects are most vulnerable to fire?
South and southwest
What fuels dry out earlier in the year?
Fuels at lower elevations
Fire is a chemical chain reaction called what?
Rapid oxidation
Light fuels are also referred to as what kind of fuels?
Fine or flashy
What are the three groups fuels are divided into?
Ground fuels
Surface fuels
Aerial fuels
What is considered a surface fuel?
Grass Forrest litter and brush up to 6 ft
What fuels do fires usually start in?
Surface fuels
What are considered aerial fuels?
6 ft or higher
Fuel loads range from what to what in grass?
1-3 tons per acre
Fuel loads range from what in timber?
200 tons per acre
For every 18 degree increase in temperature fire does what?
Doubles in speed
What are the two types of fuel moisture
Dead and live
Dead fuel moisture is influenced by what?
Relative humidity
The three factors that affect the start and spread of wildland Fire are what?
Moisture content
The size and shape of the fuel
Fuel loading
What are the most important fuel components?
Fuel moisture and temperature
At how many degrees does combustion occur in wildland fires?
500 degrees
A higher percent of spot fires will occur on what side of a fire?
The left side
Fire intensity is measured in what 2 ways?
Fireline intensity and flame length
What is the amount of heat released per foot of fire front per second
Fireline
Wind pushes fire to burn in what kind of pattern?
Oval pattern
What pattern do wildland fires generally burn in?
Elliptical pattern
