Ch.17 Flashcards
Wildland fires are most often started by ________
lightning
Debris from______ or ______ may influence the fire size and its speed and intensity.
- construction
- left behind from previous weather events
Wildland fires are affected by the _______ and _______
- rate of fire spread
- fire intensity
This is dynamic and complex:
rate of fire spread
Fire spread is affected by:
- type of fuel burning
- slope or aspect at which fire is burning
- weather conditions
_______ describes how hot a fire is burning.
Fire Intensity
Clear away dead leaves, twigs, limbs around structure, including decks and porches for a radius or _______
30 - 50 feet
Remove Tree limbs within ____ ft of ground
15 ft
Remove vegetation that is within ____ ft of a chimney or stovepipe.
15 ft
Clear a ___ foot area around liquid propane (LP) Tanks
10 ft
Stack firewood ___ ft away from structure
100 ft
There are 3 basic types of wild land fire that can occur and the level vegetation determines the type of wild land fire.
- Forest Fire
- Brush Fire
- Groundcover Fire
Occurs in areas containing heavy fuels and higher levels of vegetation, such as timber:
Forest Fire
Occurs primarily in mid-level vegetation:
Brush Fire
Type of wild land fire that involves low-level vegetation, grasses, and other light fuels:
Groundcover fire
Forest Fires often originate in remote, heavily wooded areas that are only accessible by _____ or ______
Foot or aircraft
______ produce much more heat than the other types of fires.
Forest fires
Assessing the weather should include:
- wind speed and direction’
- probable and expected changes in speed or direction
- Air temperature
- Humidity
- Approaching weather fronts or conditions
In high-level vegetation fire, a fire can work up to and rapidly across treetops, this is called:
Crown fire
*Can reverse and burn over top of previously burned area
Fire will defy gravity and quickly spread ________
up vertical slopes
Burning material that is picked up by the wind and dropped in another area, starting a separate fire:
Brands
_______ is another high-level vegetation fire hazard.
Timber
Trees that have fallen but are hung up in other trees-not fallen down to grade-are called:
Snags
Large forrest fires can potentially cover ________
several hundred to several thousand acres
These types fires do not involve heavily wooded areas, and it is possible to access fire using brush trucks:
Brush Fires
Mid-level vegetation fires grow and travel faster than Forrest fires, but they do not __________
generate high temperatures
*occur closer to wild land suburban area than forrest fire
The primary hazard of brush fires is the ________
weather
________ are the fastest growing and moving type of wild land fire, but they produce the least amount of heat.
Groundcover fires
Usually only span a few hundred square feet to several acres:
Groundcover fires
Most often ground cover fires occur in _______ and _________
- farmlands
- urban/suburban areas
The decision as to who will do the evacuating is often dictated by ____________
the fire
One major benefit of providing shelter is that:
it makes accountability of the evacuees possible
*schools are often shelters
The most important issue regarding an evacuation is ______________
When to order it
CAF’s help by:
- help water penetrate combustible materials
- Coat burning material
- Protect exposures from fire
Ways to confine wildfire:
- surround with personnel who have constructed firelines
- FF stand around perimeter ready as fire approaches
- Fireline utilizing dozers
- firefighting aircraft
- Directing to natural boundary (river or lake)
- Directing to artificial boundary (street or highway)
- Extinguishing Burning materials
- Backfiring
Fire fighters can easily remove the fuel component by:
- hand digging
- plowing
- back-burning
By ______ or ______ to remove the fuel, you can reduce the preheating of surrounding vegetation
plowing or digging
_________ is usually the safest method of extinguishment at a wildfire.
Attacking fire from the burned area and working outward
Wild land fire extinguishment operations should begin by working up the _______ from within the burned area, and then working toward the _______
- flanks
- head
The ______ of a wildfire is the fastest-growing and moving part of the fire.
Head
One way to make the best use of available water is to _________________
- lower the gallonage-per-minute (GPM) flow of the nozzle
- If automatic nozzle, lower PSI
Overhaul is often termed as __________
mop up
When water is available and accessible the entire perimeter of the fire area should be overhauled. Crews should saturate a perimeter that extends at least ____ ft. beyond the burned areas.
50 ft.
Backpacks should not be used to _____________
apply water to unburned areas. Instead used to directly extinguish flames and hotspots
Start extinguishment at the ___________, then work toward the head.
the most active flank
If fire worsens beyond expected conditions, there must be at least _________ areas for fire fighters to take refuge.
At least 1, PREFERABLY 2
Where is considered the safety zone of structure during wild fire?
Leeward side and the interior
If working along a ridge, position apparatus on the side:
opposite and below the fire
*avoid placing rig between approaching fire and structure
A fire advancing toward a structure from ___________ is much easier to defend, because it tends to progress more slowly.
above and downward
A fire advancing from ______________ travels much faster and has a greater flame length.
Below and spreading up a slope
Structures that have good clearance or green space around them, at least _______, may still be suspect because of flame length.
at least 30 ft
A structure may not be defendable if it is ________ from the edge of the clear space.
Less than twice the flame length
The sun increases the ground cover’s temperature the most in the ________, so fuels are closest to their ignition temperature at this time.
Afternoon
A __________ can help by educating home and building owners on the steps they can take to lessen the threat of wild land fires to their properties.
strong prevention/public information cmpaign
There are ____ firefighting orders that can positively impact the fire fighters safety at wild land fires
10
An area where undeveloped land with vegetative fuels mixes with human-made structures:
Wildland-urban interface
