FIRE SUPPRESSION - Natural Resource Ecology and Management
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Transcript FIRE SUPPRESSION - Natural Resource Ecology and Management
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Paper – draft due: Nov. 9
Group presentation: Nov. 18
FIRE SUPPRESSION
NREM 390 – 2 November 2010
Wildland Fire
Categories of wildland fire
Wildfire
A fire that is unwanted (from an anthropocentric
point of view) with various means of ignition
Prescribed Fire (human-ignited, natural-ignited)
A fire that is wanted for management goals, and thus
promoted
Escaped fire
A term to describe a fire in transition to wildfire
What is Fire Suppression?
The elimination or management of one or
more parts of the fire triangle to prevent
unwanted fire ignition and/or spread
FUEL
Separate fuel from other fuel (fireline)
Eliminate by burning or mechanical removal
HEAT
Reduce heat with water, dirt, foam
Inhibit combustion process by adding chemical retardants
OXYGEN
Smother the fire to remove oxygen
Only special cases where this is possible
Strategies for Fire Suppression:
Direct and Indirect Attack
Direct Attack
Attempt at immediate fire suppression; should be done
by experienced personnel given enhanced risks
Indirect Attack
More typical, involves build-up of resources and
planning for fire suppression
May use other techniques
Strategies for Fire Suppression:
Control, contain, confine
Control
Use of all resources to completely put the fire out
(federal government approach, e.g., old “10:00 AM rule”)
Contain
Using suppression methods to maintain a fire within
defined areas
Confine
Allowing a fire to burn without active suppression as long
as it remains within defined areas
Where would a prescribed fire operation typically fall?
Methods of Fire Suppression: Direct Control,
Perimeter Control, Prescription Control
DIRECT CONTROL
Immediate & complete extinguishment of fire
(removal of one or more parts of the fire triangle)
Typically used on small, isolated incidents (local
actions) or smaller parts of large fire complexes
Examples?
What concept was a famous means of direct
control?
Methods of Fire Suppression:
Perimeter control
Encirclement of a fire, confinement of active parts
of a fire to prevent further fire spread
Most common means of fire control in most
situations
Hotspotting
selectively attacking active potions through direct control
When would the fire be contained? Or controlled?
Contained: fire surrounded by a complete break in fuels
Controlled: fireline strengthened such that flareups can
not cross the fire break
Methods of Fire Suppression:
Prescription Control
Fire considered to be under prescription control as
long as it meets certain criteria, e.g., geographic
boundaries, fire behavior, weather conditions (=
“the prescription” of a fire management plan)
Suppression actions may be take to confine the fire
(= “confinement” or a “confined fire”)
Many of the same tactics utilized as with perimeter
control
Parts of a Fire
Origin
Point of ignition at which fire
began
Flank
Sides of the fire or burning area
Heading fire (Head Fire)
Leading edge of the fire as
determined by wind, slope, fuels
Backing fire
Fire that is moving against
prevailing abiotic factors
Parts of a Fire
Spot Fires
New fires or bodies of fire ignited by
embers transported away from main
body into receptive fuels
Pockets
Unburned “peninsula” of fuel
Finger
Fire that has split off from main body
and begun moving in its own (parallel)
direction
Island
Unburned fuel within a fire area
Black
Area within the perimeter of a fire
already burned out
Tactics for Fire Suppression: Firelines
Handline = built by crew using handtools (mineral soils)
Wetline = created by inundating fuels with water
Plowline, catline, tractor line = created by heavy equipment
(mineral soil)
Mowed line = fuel cut & removed
Retardant line – lines made with chemicals
Foam line – lines made with chemical foams
Hotline – Fireline constructed in direct attack
Blackline = burning out area to eliminate fuels
Building
firelines
Handline built by crew
using handtools
(mineral soils)
Blackline:
Burning out an
area to
eliminate fuels
Hotline: Fireline
constructed
under direct
attack
Tactics: Firing Operations
Burning out
cleaning out pockets of fuel by burning (parallel method of attack)
Backfiring (“counterfiring”, “suppression firing”)
Fire used as part of indirect
attack
Burning large amounts of fuel in
advance of the main fire (usually
into the wind; not always)
Replaces a fire over which
direct control is impossible with a
fire for which some control is
likely
Photo Example
Burning out
Backfiring
Functional Model for Fire Suppression
Report/Dispatch
Initial report & response to a new fire (wildfire) or
report to dispatch of new fire (prescribed)
Size-up
Taking stock of what the fire is doing upon arrival
Matching the available suppression resources with the
character of the fire
Initial Attack
First resources on scene begin to address incident after
sizing-up incident
“Smokechasing”
Functional Model for Fire Suppression
Extended Attack
When fire has grown too large to be managed strictly
on I-A and more resources are needed over a longer
period of time
Mop-up
Completely extinguishing all flame and burning fuels
within a burn area
Demobilization
Breaking down of a fire operation: I-A resources leave
scene, reverse of build-up
Rehabilitation
If needed, rehabilitation of burned area: removal of
equipment, repairing line, replanting if needed
Cerro Grande Fire
Fire Management Plan (10 years)
Phase 1 – grasslands in upper portion of unit
Phase 2 – forested area on east and west sides
Phase 3 – central wetter area
Prescribed Fire – 2000
Only Phase 1
Escaped fire wildfire fire suppression
Threatened the towns of Los Alamos and White Rock (18,000
residents)
Threatened the Los Alamos National Laboratory
Bandelier National Monument:
Cerro Grande Prescribed Fire
Scenarios
1) Slopover of main fire into the Sante Fe National Forest
Direct attack, hotspotting, direct control, mop-up
2) Slopover of main fire into the Sante Fe National Forest
Burning out, coldtrailing, coldtrail, safety zone
3) Spotting from main fire into the Phase III burn unit
Smokechasing, prescription control, fireline, confinement
4) Spotting from main fire into the Phase III burn unit, wind
from the north increasing in speed
Anchor point, backfiring, perimeter control, extended attack,
escape route
Scenarios
5) Spotting from main fire into the SE Phase II burn unit,
wind shift so that it is gusting from the west
Sizeup, Fireline (explain what kind), perimeter control,
backfiring, anchor point
6) Change in wind direction: originally from the N, now
coming from the NE and becoming gusty, causing fire to
spread into Baca Ranch
Hotline, Contain, fireline (explain what kind), counterfiring,
backing fire, lookout