wildfire glossary indexed 2008

8/14/2019 Wildfire Glossary Indexed 2008

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Preface

The AFAC Wildfire Glossary has been developed to promote an exchange of information between memberagencies on terminology used specifically in wildfires.

The Glossary has been developed based on a set of agreed business rules. It includes the wildfire technicalterms, their definition or description as adopted and applied by the AFAC member agencies. It does

include some fire terms that are of a general industry wide nature for some completeness. It excludesterms for which an agreed definition could not be reached by the member agencies.

This document is not designed to be a text book or to provide a discussion of a term beyond thedefinition/description of that term. Nor is it an attempt to modify or redefine terms defined in codes,standards or legislation. Terms that have been adopted for use by the fire management industry fromanother discipline will maintain the meaning ascribed to them in their originating discipline.

It is proposed that this Glossary will be reviewed regularly to ensure that it continues to be relevant andmeets the needs of AFAC member agencies. In time it will be expanded to include a broader range oftechnical terms and when agreement is reached on definitions for the currently excluded terms. Its form will be altered so that it can be delivered to members and the general public via the Fire KnowledgeNetwork website.

AFAC acknowledges the significant contribution of the Rural and Land Management Glossary WorkingGroup lead by Greg Esnouf and Country Fire Authority staff, Matthew Fraser and Jo Richards, whocontributed generously of their time and expertise in the development of this document and the work ofthe Genesis Institute to provide a framework for refining the glossary.

AimThe purpose of this Glossary is to seek to facilitate a greater understanding between wildfire and landmanagement agencies and support organisations during the prevention of, preparedness for, response toand recovery from wildfires.


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Index

Accelerant....................................................... 1 Air Attack Supervisor.....................................1Adaptor........................................................... 1Adsorption...................................................... 1Advance burn.................................................1 Advancing fire ................................................ 1

Aerial detection.............................................. 1 Aerial fuels ..................................................... 1Aerial ignition ................................................ 1 Aerial ignition device (AID)........................... 1Aerial Observer .............................................. 1 Aerial reconnaissance .................................... 1 Aerosol............................................................ 1AFFF...............................................................1AIIMS structure ............................................. 1 Air attack ........................................................ 1 Air base Manager...........................................1 Air mass..........................................................1

Air Observer ...................................................1 Air operations ................................................ 1Air Operations Manager ................................1 Aircraft Officer ............................................... 1 Airside ............................................................1 Allocated resources........................................2Anchor point ..................................................2 Area ignition...................................................2Area of origin .................................................2Arson..............................................................2Aspect .............................................................2Asphyxiants....................................................2 Assembly area ................................................2 Assessment.....................................................2 Assets..............................................................2 Assisting agency.............................................2 Atmospheric stability.....................................2 Attack time .....................................................2Australasian Inter-service IncidentManagement System .....................................2 Automatic dispatch........................................2Automatic weather station (AWS) ................2 Available fuel..................................................2 Available resources ........................................2Backing fire ....................................................2Bark heaps......................................................2Bark fuel .........................................................2Basal accumulation........................................2Base camp ......................................................3Bay(s) .............................................................3Beaufort wind scale........................................3Blank cap........................................................3Blow down......................................................3Blow up...........................................................3Bole.................................................................3 Bole damage...................................................3Bracken ..........................................................3Branch............................................................3Breakaway ......................................................3

Breeching ...................................................... 3Briefing.......................................................... 3Broad area hazard reduction ........................ 3Broadcast burning......................................... 3Buffer............................................................. 3Bulk water carrier ......................................... 3

Burn back ...................................................... 3Burn over....................................................... 3Burn plan....................................................... 3Burning brands ............................................. 3Burning conditions ....................................... 4Burning off .................................................... 4Burning out ................................................... 4Burning program .......................................... 4Burning rotation ........................................... 4Burning unit.................................................. 4Burnover........................................................ 4Bushfire ......................................................... 4

Bushfire danger period ................................. 4Bushfire management................................... 4Byram-Keetch Drought index (BKDI).......... 4Cache ............................................................. 4Campaign fire................................................ 4Candle (Candling) ......................................... 4Candlebark .................................................... 4Canopy........................................................... 4Canopy cover................................................. 4Canopy density.............................................. 4Central ignition............................................. 4Chaining ........................................................ 4Charged line .................................................. 4CIMS.............................................................. 4Class A foam...................................................5Class labels .....................................................5Climate ...........................................................5Clinometer......................................................5 Cloud cover.....................................................5Coarse fuels ....................................................5Code of Practice .............................................5Cold front .......................................................5Cold trailing....................................................5Collecting head...............................................5Combat agency/authority..............................5Combustion ....................................................5Command.......................................................5 Communications plan....................................5Compartment .................................................5Competency....................................................5 Conduction.....................................................5 Contained .......................................................5Contour lines..................................................5Control............................................................5 Control authority .......................................... 6Controlled...................................................... 6Controlled burning ....................................... 6Convection..................................................... 6Convection burn............................................ 6


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Convection column ........................................6Convective activity .........................................6Convergence zone ..........................................6Convoy............................................................6 Coordination ..................................................6Cordon............................................................6 Coupe..............................................................6 Crew................................................................6 Crew leader ....................................................6Critical burnout time .....................................6Critical incident stress ...................................6Critical incident stress debriefing .................6Cross bearings................................................6Crown fire.......................................................6Crown scorch..................................................7Crowning........................................................7Crowning potential ........................................7Curing.............................................................7 Dead fuel ........................................................7Deep-seated fire .............................................7Defensive strategy..........................................7Dehydration ...................................................7Delayed aerial ignition devices (DAID) ........7Deliberate fire ................................................7Delivery hose..................................................7Delivery valve.................................................7Demobilisation...............................................7 Depth of burn.................................................7Desiccant ........................................................7Desorption......................................................7 Detection ........................................................7Dew.................................................................7 Dew point temperature..................................7Dieback...........................................................7 Diffused pattern .............................................7Direct attack...................................................7Dispatch ........................................................ 8Division ......................................................... 8Dominant height........................................... 8Downwind..................................................... 8Dozer ............................................................. 8Dozer line ...................................................... 8Drain time ..................................................... 8Drift ............................................................... 8

Drip torch...................................................... 8Drop pass ...................................................... 8Drop pattern.................................................. 8Drop zone (DZ) ............................................. 8Drought ......................................................... 8Drought index ............................................... 8Dry bulb temperature ................................... 8Dry firefighting ............................................. 8Duff................................................................ 8Ecological burning ........................................ 8Edge burning................................................. 8Elevated fuel.................................................. 8

Embers .......................................................... 8Emergency centre ......................................... 8En route resources .........................................9

Entrapment ................................................... 9Equilibrium moisture content (EMC).......... 9Equipment..................................................... 9Escape route.................................................. 9Evacuation..................................................... 9Exposures...................................................... 9Extinguishing agent ...................................... 9Extreme fire behaviour ................................. 9Extreme fire danger ...................................... 9Facilities ........................................................ 9Fall back fire control line.............................. 9Fine fuel......................................................... 9Fingers........................................................... 9Fire ................................................................ 9Fire access track...........................................10Fire behaviour..............................................10Fire Behaviour Analyst ................................10Fire behaviour prediction............................10Fire behaviour model...................................10Fire behaviour prediction system................10Fire bombing................................................10Fire brand.....................................................10Fire climate ..................................................10Fire control...................................................10Fire control line............................................10Fire crew.......................................................10Fire danger...................................................10Fire danger class ..........................................10Fire danger index.........................................10Fire danger rating ........................................10Fire ecology ..................................................10Fire edge.......................................................10Fire effects....................................................10Fire environment .........................................10Firefighter ....................................................10Firefighting operations ................................10Fire frequency ..............................................10Fire front ...................................................... 11Fireground.................................................... 11Fire hazard ................................................... 11Fire intensity ................................................ 11Fireline ......................................................... 11Fireline intensity .......................................... 11Fire lookout .................................................. 11

Fire management ......................................... 11Fire regime ................................................... 11Fire report .................................................... 11Fire retardant ............................................... 11Fire risk ........................................................ 11Fire run......................................................... 11Fire scar........................................................ 11Fire season ................................................... 11Fire simulator............................................... 11Fire spread ...................................................12Fire storm.....................................................12Fire suppressant...........................................12

Fire suppression organisation.....................12Fire suppression plan ..................................12Fire tetrahedron...........................................12


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Fire threat.....................................................12Fire tower .....................................................12Fire triangle..................................................12Fire weather .................................................12Fire weather forecast ...................................12Fire whirl......................................................12Fire wind ...................................................... 12First attack ...................................................12Fixed wing aircraft .......................................12Flame angle..................................................12Flame depth .................................................12Flame height ................................................12Flame length ................................................13Flammability................................................13Flammable ...................................................13Flank attack..................................................13Flanks of a fire..............................................13Flare up ........................................................13Flash fire.......................................................13Foam.............................................................13 Foam Class A................................................13Foam Class B................................................13Foam blanket ...............................................13Foam concentrate ........................................13Foam inductor..............................................13Foam solution .............................................. 13Forest fire .....................................................13Forest type....................................................13Forward looking infrared (FLIR) ................13Forward rate of spread ................................ 13Frontal fire intensity ....................................13Front end loader ..........................................13Fuel...............................................................13Fuel age ........................................................13Fuel arrangement.........................................14Fuel array .....................................................14Fuel assessment ...........................................14Fuel bed depth .............................................14Fuelbreak .....................................................14Fuelbreak system.........................................14Fuel continuity.............................................14Fuel depth ....................................................14Fuel load.......................................................14Fuel management ........................................14

Fuel model....................................................14Fuel modification.........................................14Fuel moisture content..................................14Fuel moisture differential............................14Fuel map.......................................................14Fuel profile ...................................................14Fuel quantity ................................................14Fuel reduction burning................................14Fuel reduction..............................................14Fuel separation ............................................14Fuel type.......................................................14Fuel weight................................................... 15

General origin area ...................................... 15Going fire...................................................... 15Grass fire ...................................................... 15

Grassland curing..........................................15Grid ignition.................................................15Ground crew.................................................15Ground fire...................................................15Ground fuels.................................................15Habitat..........................................................15 Hand crew ....................................................15Hand line......................................................15Hang up........................................................15Hand trail .....................................................15Hazard..........................................................15Hazard reduction .........................................15Head .............................................................15Head attack ..................................................15Head fire.......................................................15Heat exhaustion ...........................................15Heat stress....................................................15Heat stroke ...................................................15Heavy fuels...................................................15Heel ..............................................................15Heel fire........................................................15Helibase (HB)...............................................15Helicopter.....................................................15 Helipad (HP)................................................16Helitack crew................................................16Heli torch......................................................16High intensity fire ........................................16Hold over fire ...............................................16Hop over.......................................................16Hose bandage...............................................16Hose strangler ..............................................16Hot Refueller................................................16Hot spot........................................................16Humus..........................................................16Hygrometer ..................................................16Ignition.........................................................16Ignition pattern............................................16Ignition source .............................................16Incendiary ....................................................16Incendiary device.........................................16Incident ........................................................16Incident Action Plan (IAP) ..........................16Incident control ...........................................16Incident control system (ICS) .....................16

Incident Controller ......................................16Incident management..................................16Incident Management Team (IMT) ............16Incident objective......................................... 17Incident strategies ....................................... 17Indirect attack.............................................. 17Induced wind ............................................... 17Infrared scanning......................................... 17Instability .....................................................17Interface ....................................................... 17Initial attack ................................................. 17Inversion ...................................................... 17

Island............................................................17Isobar............................................................ 17I zone ............................................................17


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Junction zone............................................... 17Jump fire ...................................................... 17Keetch-Byram Drought Index (KBDI) ........ 17Knock down.................................................. 17Ladder fuels.................................................. 17Lag time........................................................ 17Lead agency.................................................. 17Lee (leeward) ...............................................18Legislation....................................................18 Light fuel ......................................................18Light patrol unit...........................................18Lightning......................................................18Lightning fire ...............................................18Lightning formation ....................................18Lighting pattern ...........................................18Litter.............................................................18 Litter bed fuel...............................................18Litter fall.......................................................18Living fuels...................................................18Living shrub fuel ..........................................18Local winds ..................................................18Log................................................................18Logistics .......................................................18Lookout ........................................................18Lookout tower..............................................18Low intensity fire .........................................18Medium fuels ...............................................18Mineral earth ...............................................18Mobilisation.................................................18Moisture content..........................................18Mosaic ..........................................................19Move up method..........................................19Multi-agency response.................................19Natural barrier.............................................19Near surface fuels ........................................19Needle bed....................................................19Nozzle ...........................................................19Objective.......................................................19 One lick method...........................................19Operations....................................................19 Operations point..........................................19Parallel attack...............................................19Parallel fire suppression..............................19Parallel method............................................19

Parts of a Fire...............................................19Patch burning...............................................19Patrol ............................................................19Peat...............................................................19Perimeter..................................................... 20Permit burn................................................. 20Personal Protection Equipment (PersonalProtective Clothing) .................................... 20Plan of attack............................................... 20Planned burning ......................................... 20Pocket .......................................................... 20Point of attack ............................................. 20

Point of origin ............................................. 20Portable dam............................................... 20Predicted rate of spread.............................. 20

Pre-incident plan ........................................ 20Pre-suppression plan.................................. 20Prepared community .................................. 20Pre-planned dispatch.................................. 20Prescribed burn...........................................20Prescribed burn plan .................................. 20Prescribed burning ..................................... 20Prescribed fire ............................................. 20Prescription................................................. 20Profile litter moisture content.................... 20Profile moisture content............................. 20Psychrometer .............................................. 20Pulaski tool...................................................21Pumper .........................................................21Quick-fill pump............................................21Rain gauge....................................................21Rakehoe (McLeod tool) ...............................21Rate of spread ..............................................21Reaction time ...............................................21Rear ..............................................................21Reburn..........................................................21 Reconnaissance............................................21 Recovery .......................................................21Regeneration burn.......................................21Re-ignition ...................................................21Relative humidity (RH) ...............................21Relay pumping .............................................21Relief.............................................................21 Report of fire ................................................21Residence time.............................................21Resources .....................................................21Response ......................................................21Response time..............................................21Responsible authority..................................21Retardant .................................................... 22Risk analysis................................................ 22Risk.............................................................. 22Rural............................................................ 22Rural Urban interface ................................. 22Safe .............................................................. 22Safety zone .................................................. 22Scorch height............................................... 22Scout............................................................ 22Scrub............................................................ 22

Scrub fire ..................................................... 22Secondary fire control line.......................... 22Sector........................................................... 22Seen area ..................................................... 22Shift ............................................................. 22Shift change................................................. 22Situation report (Sitrep) ............................. 22Size up ......................................................... 22Slash ............................................................ 22Slash burn ................................................... 22Sleeper......................................................... 23Slip-on unit ................................................. 23

Smoke management ................................... 23Smoker ........................................................ 23Softwood...................................................... 23


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Southern Oscillation Index (SOI)............... 23Soil Dryness Index (SDI) ............................ 23Spark arrestor ............................................. 23Spot fire....................................................... 23Spotting ....................................................... 23Staging area................................................. 23Stand by....................................................... 23Static water supply...................................... 23Step-up method .......................................... 23Strike teams ................................................ 23Strip burning............................................... 23Strip ignition ............................................... 23Stripping...................................................... 23Structure...................................................... 23Subsurface fire ............................................ 23Suction hose ................................................ 24Supply hose ................................................. 24Support agency ........................................... 24Surface fire .................................................. 24Surface fuel.................................................. 24Surface moisture content............................ 24Tactics ......................................................... 24Tail fire ........................................................ 24Tanker ......................................................... 24Task force .................................................... 24Technical advisors ...................................... 24Temperature (dry bulb) .............................. 24Temperature (wet bulb).............................. 24Test fire ....................................................... 24Thermal imagery......................................... 24Thermohygrograph..................................... 24

Time lag....................................................... 24Tongues ....................................................... 24Topography ................................................. 24Torch ........................................................... 24Torching ...................................................... 24Travel time .................................................. 24Under storey................................................ 24Urban........................................................... 25Urban Interface........................................... 25Urban Rural interface ................................. 25Values at risk............................................... 25Warning device ........................................... 25Water bombing ........................................... 25Water point ................................................. 25 Water tank................................................... 25 Wetting agent.............................................. 25Widow maker.............................................. 25 Wildfire........................................................ 25Wildfire control plan................................... 25Wildland Urban Interface (WUI)............... 25Wind direction ............................................ 25 Wind throw ................................................. 25 Windfall....................................................... 25Wind speed.................................................. 25Wind strength ............................................. 25 Windrow...................................................... 25Windrow burning........................................ 25 Windward.................................................... 25 Woodland .................................................... 25


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Wildfire Glossary

Term Definition

Accelerant Any substance (such as oil, gasoline, etc) that is applied to a fuel-bed toexpedite the burning process.

Air Attack Super visor Primarily responsible for the safety and efficient tactical coordination ofaircraft operations when fixed and/or rotary firebombing aircraft areoperating at a fire (Air Attack Supervisor Training Manual).

Adaptor A fitting used to couple different sized hoses, hoses of the same size withdifferent threads, or different types of couplings, or to connect the male tomale, or female to female parts of the same type of coupling.

Adsorption The taking in of water vapour from the air by dead plant material.

Advance bur n A prescribed fire that reduces fuel through a forest area before fellingoperations. It is intended to improve the safety of timber harvestingoperations and as a silvicultural tool to protect lignotubers and standingtrees.

Advancing fire That portion of the fire with rapid fire spread and higher intensity which isnormally burning with the wind and/or up slope.

Aerial detection The discovering, locating and reporting of fires from aircraft.Aerial fuels See: elevated fuels

Aerial ignition Ignition of fuels by dropping incendiary devices or materials from aircraft.

Aerial ignition device(AID)

Inclusive term applied to equipment designed to ignite wildland fuels froman aircraft.

Aerial Obser ver See: Air Observer

Aerial reconnaissan ce Use of aircraft for detection of fires and observing fire behaviour, values-at-risk, suppression activity, and other critical factors to facilitate commanddecisions on strategy and tactics needed for fire suppression.

Aerosol Airborne solid or liquid particles dispersed or suspended in a gas stream.

AFFF See: Aqueous film-forming foam.

AIIMS structur e The combination of facilities, equipment, personnel, procedures, andcommunications operating within a common organisational structure withresponsibility for the management of allocated resources to effectivelyaccomplish stated objectives relating to an incident (AIIMS).

Air attack The direct use of aircraft in the suppression of wildfires.

Air base Man ager An experienced, trained person who is appointed to manage all thefunctions and personnel on an air base or helicopter base.

Air ma ss A meteorological term referring to an extensive body of air within which theconditions of temperature and moisture in a horizontal plane are

essentially uniform.

Air Obser ver The primary role of the air observer is to aerially obtain intelligence toassist the planning of fire suppression operations (NSWRFS).

Air opera tions The use of aircraft in support of an incident for the purposes ofsuppression, transportation of personnel, equipment or supplies, or foraerial reconnaissance.

Air Operations Man ager The air operations manager position is responsible for overall coordinationof air operations and air support activities in support of an incident.

Aircraft Officer The aircraft officer is responsible for ground operations and overallprovision of support, enabling a safe and efficient air operation to beconducted.

Airside The parts of an airport not normally open to unauthorised people. Itcomprises the apron, taxiways, runways and the areas containing them.

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Wildfire Glossary

Term Definition

Allocated resour ces Resources working at an incident (AIIMS).

Anchor po int An advantageous location, usually a barrier to fire spread, from which tostart constructing a fireline. The anchor point is used to minimize thechance of being flanked by the fire while the line is being constructed(NWCG).

Area ignition Ignition of several individual fires throughout an area, eithersimultaneously or in rapid succession, and so spaced that they add to andinfluence the main body of the fire to produce a hot, fast-spreading firecondition. Also called simultaneous ignition.

Area o f origin General location where the fire started.

Arson The deliberate setting of a fire where the intent of the person responsiblewas to cause harm or destruction to life or property.

Aspect The direction towards which a slope faces.

Asphyxiants Substances which interfere with the respiratory process.

Assembly are a See Staging area.

Assessment The process of determining if an individual has the prescribed skills,knowledge and experience needed to acquire a specific capability.

Assets Anything valued by people which includes houses, crops, forests and, inmany cases, the environment.

Assisting agency An agency directly contributing suppression, support or service resourcesto another agency.

Atmosph eric stability The degree to which the atmosphere resists turbulence and verticalmotion.

Attack tim e See Elapsed time

Australasian Inter-service IncidentManagement System

A nationally adopted structure to formalise a coordinated approach toemergency incident management.

Automa tic dispatch See Pre Planned Dispatch.

Automa tic weatherstation (AW S)

The Bureau's standard AWSs use sensors to monitor temperature,humidity, wind speed and direction, pressure and rainfall. Variousadvanced sensors are available for specialised applications. Thesesensors can monitor cloud height (ceilometer), visibility, present weather,thunderstorms, soil temperature (at a range of depths) and terrestrialtemperature. (Developed from the BOM)

Available fuel The portion of the total fuel that would actually burn under variousenvironmental conditions.

Available resour ces The resources at an incident and available for allocation at short notice.(AIIMS)

Backing fire The part of a fire which is burning back against the wind, where the flameheight and rate of spread is minimal.

Bark heaps Accumulations of bark and branch material resulting from timberharvesting operations. Soil may be mixed with bark heaps, but generallythe heap is formed by a machine dropping fresh bark on the top of theheap.

Bark fuel The flammable bark on tree trunks and upper branches.

Basal accumulation Bark fallen from a tree and forming an exceptionally high and localized

accumulation of fine fuel.

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Wildfire Glossary

Term Definition

Base camp A location where personnel are accommodated and fed for a period oftime. A base camp usually contains catering, ablution and accommodationfacilities, a water supply and a lighting system, and may include otherfacilities such as car parking maintenance and servicing. (AIIMS)

Bay(s) A marked indentation (s) in the fire perimeter usually located between two

fingers.Beaufor t wind scale A system for estimating wind speeds based on observation of visible wind

effects. A series of descriptions of visible wind effects upon land objects orsea surfaces is matched with a corresponding series of wind speedranges, each being allocated a Beaufort number.

Blank cap The metal cap used on delivery outlets and on the suction inlet of thepump to prevent discharge of water.

Blow down See: Windfall.

Blow up Sudden increase in fireline intensity or rate of spread of a fire sufficient topreclude direct control or to upset existing suppression plans. Oftenaccompanied by violent convection and may have other characteristics of

a fire storm. (NWCG)

Bole The trunk of a tree.

Bole damage The damage to the trunk of a living tree by fire, mechanical equipment ordisease.

Bracken Bracken fern varies significantly in height and density. If Bracken isgenerally upright (either alive or dead) with the majority of its biomass inthe top half of the plant and only the stems in touch with the ground, then itis considered to be part of the elevated fuel. If however, it has collapsedand most of its biomass is in touch with the ground, then it is considered tobe Near-surface fuel.

Branch A tapered pipe, fitted to the end of a hose line, which increases thevelocity (converting pressure energy to kinetic energy) of the water orfoam solution travelling through the hose, and forms an effectivefirefighting jet or spray.

Breakaway The points at which a fire, after it has been contained, escapes intounburnt areas across a fireline or fire edge.

Breeching A device to divide one hose line into two or collect two hose lines into one.

Briefing A general overview of an operation.

Broad area hazardreduction

Large scale removal of selected fuel before the onset of a wildfire dangerperiod.

Broadcast burning See: Prescribed Burning (Preferred term)

Buffer A strip or block of land on which the fuels are reduced to provideprotection to surrounding lands.

Bulk water carrier A large tanker used for replenishing water to firefighting tankers.

Burn back The effect of flames spreading back over an area previously extinguished.

Burn over A section of fire that overruns personnel and/or equipment.

Burn plan The plan which is approved for the conduct of prescribed burning. Itcontains a map identifying the area to be burnt and incorporates thespecifications and conditions under which the operation is to beconducted. Also see: prescribed burn plan.

Burning brands Lofted burning material such as bark, usually flaming.

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Wildfire Glossary

Term Definition

Burning conditions The state of the combined components of the fire environment thatinfluence fire behaviour and fire impact in a given fuel type. Usuallyspecified in terms of such factors as fire weather elements, fire dangerindices, fuel load and slope.

Burning off Generally setting fire - with more or less regard to areas carrying

unwanted vegetation such as rough grass, slash and other fuels.Burning out To intentionally light fires to consume islands of unburned fuel inside the

fire perimeter.

Burning program A program of prescribed burns scheduled these for a designated area overa nominated time, normally looking ahead over one fire season (for thecoming spring to the following autumn), but can also look ahead five yearsor more.

Burning rotation The period between reburning of a prescribed area for managementpurposes.

Burning unit A specified land area for which prescribed burning is planned.

Burnover See burn overBushfire A general term used to describe a fire in vegetation.

Bushfire danger period A period of the year either established by legislation or declared by therelevant agency, when restrictions are placed on the use of fire due to dryvegetation and the existence of conditions conducive to the spread of fire.

Bushfire management All those activities directed to prevention, detection, damage mitigation,and suppression of bushfires. Includes bushfire legislation, policy,administration, law enforcement, community education, training of firefighters, planning, communications systems, equipment, research, and themultitude of field operations undertaken by land managers and emergencyservices personnel relating to bushfire control. (abbreviated) (WA BF)See: Fire Management (Preferred term)

Byram-Keetch Droughtindex (BKDI)

See: KBDI

Cache A predetermined complement of supplies stored in a designated location.(CIMS). (NZ)

Campaign fire A fire normally of a size and/or complexity that requires substantialfirefighting resources, and possibly several days or weeks to suppress.

Candle (Candling) A tree (or small clump of trees) is said to candle when its foliage ignitesand flares up, usually from the bottom to top.

Candlebark Long streamers of bark that have peeled from some eucalypt species thatform fire brands conducive to very long distance spotting.

Canopy The crowns of the tallest plants in a forest the overstorey cover.

Canopy cover Canopy cover refers to 2 dimensions (ie plan view, area coverage)

Canopy density Canopy density refers to 3 dimensions (ie mass/volume)

Central ignition A method of prescribed burning in which fires are set in the centre of anarea to create a strong convective column. Additional fires are then setprogressively closer to the outer control lines causing indraft winds to buildup. This has the effect of drawing the fires towards the centre.

Chaining The process of flattening vegetation (usually mallee or scrub) by dragginga heavy chain or cable between two large tractors or bulldozers.

Charged line A line of fire hose filled with water under pressure and ready to use.CIMS Coordinated Incident Management System used in New Zealand.

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Wildfire Glossary

Term Definition

Class A foam See: Foam

Class labels Class labels identify the type of hazardous material being stored ortransported. These are grouped under broad classifications according tothe predominant type of risk involved.

Climate The atmospheric conditions of a place over an extended period of time.

Clinometer An instrument used to measure the angle of a slope.

Cloud cover The amount of sky covered or obscured by cloud, expressed in eighths.Eight eighths is complete cloud cover.

Coarse fuels Dead woody material, greater than 25mm in diameter, in contact with thesoil surface (fallen trees and branches). Some researchers categoriseforest fuels as: fine 25mm diameter.

Code of Pra ctice Document giving methods developed to assist compliance with acts andregulations in the performance of work.

Cold front A cold front is the delineation between cold polar air moving towards the

equator and undercutting warm tropical air moving poleward. Thetemperature differences across a cold front can be extreme andassociated with strong winds. The warm tropical air is forced to rise andbecome unstable with the development of large cumuliform clouds. Severeweather such as thunderstorms, squall lines and severe turbulence mayaccompany these cold fronts. (BOM)

Cold trailing A method of determining whether or not a fire is still burning, involvingcareful inspection and feeling with the hand, or by use of a hand-heldinfrared scanner, to detect any heat source.

Collecting he ad A collecting head is used to collect (usually from two to four) lines into thesuction inlet of a pump.

Comba t agency/authority See: Control authority

Combustion Rapid oxidation of fuels producing heat, and often light.

Command The direction of members and resources of an agency in the performanceof the agencys role and tasks. Authority to command is established inlegislation or by agreement within an agency. Command relates toagencies and operates vertically within an agency.

Communications plan Details the methods and systems for people to communicate with eachother, the incident management structure, including the actual radiochannels/mobile phone numbers. (AIIMS)

Compartment (1) Forestry Definition A basic administrative unit of a managed forest.

(2) Building Definition - An enclosed space with floor, walls and ceiling.Competency Skills and knowledge and their application within an occupation to the

standard of performance required in the workplace. (Vic report)

Conduction See: Heat Transfer

Contained The status of a wildfire suppression action signifying that a control line hasbeen completed around the fire, and any associated spot fires, which canreasonably be expected to stop the fires spread. (NWCG)

Contour lines Contour lines connect points of equal elevation on a topographical map.

Control The overall direction of response activities in an emergency situation.Authority for control is established in legislation or in an emergency

response plan, and carries with it the responsibility for tasking andcoordinating other agencies in accordance with the needs of the situation.Control relates to situations and operates horizontally across agencies.

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Wildfire Glossary

Term Definition

Control authority The agency, service, organization or authority with legislative responsibilityfor control of the incident. (Also referred to as the responsible authority oragency.) (AFAC)

Controlled The stage during fire suppression activities at which the completeperimeter of a fire is secured and no breakaway is expected.

Controlled burning See: Prescribed burning.

Convection 1. As applied in meteorology, atmospheric motions that are predominantlyvertical, resulting in vertical transport and mixing of atmosphericproperties; distinguished from advection.

2. As applied in thermodynamics convection, along with conduction andradiation, is a principal means of energy transfer.

Convection burn See: Central Point Ignition

Convection colum n The rising column of smoke, ash, burning embers and other particle mattergenerated by a fire.

Convective activity General term for manifestations of convection in the atmosphere, alluding

particularly to the development of convective clouds and resulting weatherphenomena, such as showers, thunderstorms, squalls, hail, andtornadoes. (NWCG)

Convergence zone 1. The area of increased flame height and fire intensity produced when twoor more fire fronts burn together.

2. In fire weather, that area where two winds come together from oppositedirections and are forced upwards often creating clouds and precipitation.(NWCG) See: also Junction Zone

Convoy Two or more vehicles driving together under the control of a single ConvoyLeader.

Coordination The bringing together of agencies and elements to ensure effectiveresponse to an incident or emergency. It is primarily concerned with thesystematic acquisition and application of resources in accordance with therequirements imposed by the emergency or emergencies. Coordinationrelates primarily to resources and operates:

vertically, within an agency, as a function of the authority to command; horizontally, across agencies, as a function of the authority to control.

Cordon A cordon is the means to maintain an area and is used to restrictmovement into and out of an area.

Coupe A defined forest area in which timber harvesting takes place.

Crew The basic unit of a wildfire suppression force. It normally consists of two or

more personnel.Crew leader Person responsible for the supervision and management of crews

Critical burno ut time Total time a fuel can burn and continue to feed energy to the base of aforward-travelling convection column.

Critical incident stress Unusually strong emotional reactions which have the potential to interferewith the ability of personnel to function, either at the incident scene orlater, arising from any situation faced during operations.

Critical incident stressdebriefing

The process in which teams of professional and peer counsellors provideemotional and psychological support to incident personnel who are orhave been involved in a critical (highly stressful) incident.

Cross bearings Intersecting lines of sight from two or more points on the same object;used to determine the location of wildfire from lookouts.

Crown fire A fire that advances from top to top of trees or shrubs.

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15/33

Wildfire Glossary

Term Definition

Crown scorch Browning of the needles or leaves in the crown of a tree or shrub causedby heat from a fire.

Crowning A fire ascending into the crowns of trees and spreading from crown tocrown.

Crowning potential A probability that a crown fire may start, calculated from inputs of foliage

moisture content and height of the lowest part of the tree crowns abovethe surface. (NWCG)

Curing Drying and browning of herbaceous vegetation due to mortality orsenescence.

Dead fuel Fuels with no living tissue in which moisture content is governed almostentirely by absorption or evaporation of atmospheric moisture (relativehumidity and precipitation). (NWCG)

Deep-seated fire A fire burning far below the surface in duff, mulch, peat, or othercombustibles as contrasted with a surface fire.

Defensive strategy A firefighting strategy used where the protection of live and assets is a

priority but a fire is:(i) located in inaccessible or remote location OR

(ii) too intense to be safely or effectively attacked directly

Dehydration Excessive loss of water from the bodys tissues. Dehydration may followany condition in which there is a rapid depletion of body fluids.

Delayed aer ial ignitiondevices (DAID)

An incendiary device that will ignite after a predetermined time.

Deliberate fire A fire resulting from a person placing burning material to cause ignition.The intent of the person may have been to cause harm or destruction tolife or property (arson-criminal offence) or to modify fuels and/or vegetationfor land management purposes (summary offence). See also Arson.

Delivery hose Hose used to transport water under pressure.

Delivery valve On a pump, the valved outlet through which water is discharged.

Demobilisation The orderly release of resources no longer required at an incident.

Depth of burn The reduction in forest floor thickness (cm) due to consumption by fire;most commonly used in connection with prescribed burning

Desiccant A chemical that, when applied to a living plant causes or accelerates thedrying out of its aerial parts.

Desorption The loss of moisture to the atmosphere from dead plant material.

Detection The discovery of a fire. Individuals, fire towers, reconnaissance aircraftand automatic devices may be used, either alone or in combination.

Dew The moisture which collects in small droplets on the surface of substancesand vegetation by atmospheric condensation, chiefly at night.

Dew point temperature This is a measure of the moisture content of the air and is the temperatureto which air must be cooled in order for dew to form. The dew-point isgenerally derived theoretically from dry and wet-bulb temperatures, with acorrection for the site's elevation. (BOM)

Dieback The progressive dying, from the top downward, of twigs, branches or treecrowns.

Diffused pattern A spray pattern (as opposed to straight stream) of water or foam.

Direct attack A method of fire attack where wet or dry firefighting techniques are used. Itinvolves suppression action right on the fire edge which then becomes thefireline.

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16/33

Wildfire Glossary

Term Definition

Dispatch The act of ordering attack crews and/or support units to respond to a fire,or from one place to another.

Division A portion of the incident comprising of two or more sectors. The number ofsectors grouped in a Division should be such as to ensure effectivedirection and control of operations. Divisions are generally identified by a

local geographic name.Dominant height The average of the height of the three largest diameter trees selected on a

plot by a technique of variable probability sampling.

Downwind Away from the wind; in the direction opposite to the direction from whichthe wind is blowing.

Dozer A crawler tractor fitted with a blade which can be transported to a fire on atray truck or trailer. Dozer is a shortened form of "Bulldozer"

Dozer line Fireline constructed by the front blade of a dozer.

Drain time The time (minutes) it takes for foam solution to drop out from the foammass; for a specified percent of the total solution contained in the foam to

revert to liquid and drain out of the bubble structure.Drift The effect of wind on smoke or on a water drop.

Drip torch A canister of flammable fuel fitted with a wand, a burner head and a fuelflow control device. It is used for lighting fires for prescribed burning,backburning and burning out.

Drop pass Indicates that the air tanker has the target in sight and will make aretardant drop on this run over the target.

Drop pattern The distribution of an aerially delivered retardant drop on the target area interms of its length, width, and momentum (velocity x mass) as itapproaches the ground. The latter determines the relative coverage levelof the fire retardant on fuels within the pattern.

Drop zone (DZ) Target area for airtankers, helitankers, or cargo dropping.

Drought Prolonged absence or marked deficiency of precipitation (rain). (BOM)

Drought index A numerical value reflecting the dryness of soils, deep forest litter, logsand living vegetation.

Dry bulb temperature Technically, the temperature registered by the dry-bulb thermometer of apsychrometer. However, it is identical to the temperature of the air.(Degrees Celsius). (NZ)

Dry firefighting The suppression of a fire without the use of water. This is normallyachieved by removing the fuel by the use of hand tools, burning ormachinery.

Duff The layer of decomposing vegetative matter on the forest floor below thelitter layer, the original structure still being recognisable.

Ecological burnin g A form of prescribed burning. Treatment with fire of vegetation innominated areas to achieve specified ecological objectives.

Edge burning A term used to describe perimeter burning of an area in mild conditionsprior to large scale prescribed burning. This practice is used to strengthenbuffers and to reduce mop-up operations.

Elevated fuel The standing and supported combustibles not in direct contact with theground and consisting mainly of foliage, twigs, branches, stems, bark andcreepers.

Embers Glowing particles cast from the fire (as showers or storms). (Vic report)Emergency centre A facility where the coordination of the response and support to the

incident is provided.

8


17/33

Wildfire Glossary

Term Definition

En route resources Resources despatched to an incident that have not yet checked in.(AIIMS)

Entrapment A situation in which individuals are exposed to life threatening orpotentially life threatening conditions from which they cannot safelyremove themselves.

Equilibrium moisturecontent (EMC)

The moisture content that a fuel element would attain if exposed for aninfinite period in an environment of specified constant dry-bulbtemperature and relative humidity. When a fuel element has reached itsEMC, it neither gains nor loses moisture as long as conditions remainconstant.

Equipment All material supplied to an incident excluding personnel and vehicles.

Escape route A planned route away from danger areas at a fire.

Evacuation The temporary relocation of persons from dangerous or potentiallydangerous areas to safe areas.

Exposures Parts of the same structure or other structures or property not directly

involved in the fire but at risk of being burnt or damaged if the fire is notcontrolled. In the wildfire context:

1. Property that may be endangered by a fire burning in another structureor by a wildfire. In general, property within 12 metres of a fire may beconsidered to involve an exposure hazard, although in very large fires thedanger may exist at much greater distances.

2. Direction in which a slope faces, usually with respect to cardinaldirections (N, S, E, W).

3. The general surroundings of a site, with special reference to itsopenness to winds and sunshine.

Extinguishing agent A substance used to put out a fire by cooling the burning material or

blocking the supply of oxygen, or chemically inhibiting combustion or acombination of.

Extreme fire behaviour A level of wildfire behaviour characteristics that ordinarily precludesmethods of direct suppression action. One or more of the following isusually involved: high rates of spread prolific crowning and/or spotting presence of fire whirls a strong convective column.Predictability is difficult because such fires often exercise some degree ofinfluence on their environment and behave erratically, sometimesdangerously.

Extreme fire danger The highest fire danger classification.

Facilities Permanent and temporary facilities where personnel sleep, cook, maintainand repair equipment. (AIIMS)

Fall back fire control line Any fire control line which is at a distance from the fire perimeter, and isthe second control line at which the fire perimeter may be stopped shouldit cross the first fire control line. Also known as 'fallback line'.

Fine fuel Fuel such as grass, leaves, bark and twigs less than 6mm in diameter thatignite readily and are burnt rapidly when dry.

Fingers Long and narrow slivers of fire which extend beyond the head or flanks.(AFAC)

Fire The chemical reaction between fuel, oxygen and heat. Heat is necessaryto start the reaction and once ignited, fire produces its own heat andbecomes self-supporting.

9


18/33

Wildfire Glossary

Term Definition

Fire access track A track constructed and/or maintained expressly for fire managementpurposes.

Fire behaviour The manner in which a fire reacts to the variables of fuel, weather andtopography.

Fire Behaviour Analyst Person responsible for developing fire behaviour predictions based on fire

history, fuel, weather, and topography. (NWCG)amended

Fire behaviour prediction Prediction of probable fire behaviour usually prepared by a fire behaviouranalyst in support of fire suppression or prescribed burning operations.(NWCG)

Fire behaviour m odel A set of mathematical equations that can be used to predict certainaspects of fire behaviour.

Fire behaviour predictionsystem

A system that uses a set of mathematical equations to predict certainaspects of fire behaviour in wildland fuels when provided with data on fueland environmental conditions.

Fire bombing A technique of suppressing a wildfire by dropping water, foam or

retardants on it from an aircraft.Fire brand A piece of flaming or smouldering material capable of acting as an ignition

source. eg eucalypt bark.

Fire climate The composite pattern or integration over time of the fire weather elementsthat affect fire occurrence and fire behaviour in a given area.

Fire control See Fire suppression.

Fire control line See: Fireline.

Fire crew A general term for two or more firefighters organised to work as a unit.(NWCG)

Fire danger Sum of constant danger and variable danger factors affecting the

inception, spread, and resistance to control, and subsequent fire damage;often expressed as an index. (NWCG)

Fire danger class A segment of a fire danger index scale identified by a descriptive term(e.g. Low, Moderate, High, Very High, Extreme) and/or a colour code. Theclassification system may be based on more than one fire danger index.

Fire danger index See: fire danger rating

Fire danger rating A relative number denoting an evaluation of rate of spread, or suppressiondifficulty for specific combinations of fuel, fuel moisture and wind speed.Rated as low, moderate, high, very high, extreme, indicating the relativeevaluation of fire danger.

Fire ecology The study of the relationships between fire, the physical environment andliving organisms.

Fire edge Any part of the boundary of a going fire at a given time. NOTE: The entireboundary is termed the fire perimeter.

Fire effects The physical, biological and ecological impact of fire on the environment.(NWCG)

Fire environment The surrounding conditions, influences, and modifying forces oftopography, fuel, and weather that determine fire behaviour. (NWCG)

Firefighter Any employee, volunteer or agent of any fire agency who occupies, or isdesignated, to undertake a role for the purpose of fire suppression.

Firefighting operations Any work or activity directly associated with control of fire.

Fire frequency A general term referring to the recurrence of fire in a given area over time(NWCG). Also see: Fire regime

10


19/33

Wildfire Glossary

Term Definition

Fire front The part of a fire within which continuous flaming combustion is takingplace. Unless otherwise specified, the fire front is assumed to be theleading edge of the fire perimeter. In ground fires, the fire front may bemainly smouldering combustion. (NWCG)

Fireground The area in the vicinity of a fire suppression operations, and the area

immediately threatened by the fire. It includes burning and burnt areas;constructed and proposed fire lines; the area where firefighters, vehicles,machinery and equipment are located when deployed; roads and accesspoints under traffic management control; tracks and facilities in the areasurrounding the actual fire; and may extend to adjoining area directlythreatened by the fire.

Fire hazard A fuel complex, defined by volume, type condition, arrangement, andlocation, that determines the degree of ease of ignition and of resistance tocontrol.

Fire intensity See: Fireline intensity.

Fireline A natural or constructed barrier, or treated fire edge, used in firesuppression and prescribed burning to limit the spread of fire.

Fireline intensity The rate of energy release per unit length of fire front usually expressed inkilowatts per metre (Kw/m). The rate of energy release per unit length offire front, defined by the equation I=Hwr, whereI = fireline intensity (kW/m)H = heat yield of fuel (kJ/kg)-16,000 kJ/kg w = dry weight of fuel consumed(kg/m2) (mean total less mean unburnt)r = forward rate of spread (m/s)The equation can be simplified to I = w r/2where I = fireline intensity (kW/m)w = dry weight of fuel consumed (tonnes/ha)r = forward rate of spread (m/hr)

Fire lookou t A structure strategically located and manned to detect the occurrence andthe location of fires. It may be a tower or a structure on a high point

Fire management All activities associated with the management of fire prone land, includingthe use of fire to meet land management goals and objectives.

Fire regime The history of fire in a particular vegetation type or area including thefrequency, intensity and season of burning. It may also include proposalsfor the use of fire in a given area. (AFAC)

Fire report An official record of a fire, generally including information on cause,location, action taken, damage, costs, etc., from start of the fire untilcompletion of suppression action. These reports vary in form and detailfrom agency to agency (NWCG). Also see Report of Fire

Fire retardant A chemical generally mixed with water, designed to retard combustion. It isapplied as slurry from the ground or the air.

Fire risk Processes, occurrences or actions that increase the likelihood of firesoccurring.

Fire run A rapid advance of a fire front. It is characterised by a marked transition inintensity and rate of spread.

Fire scar 1) A healing or healed-over injury caused or aggravated by fire on a woodyplant.

2) A mark left on a landscape by fire.

Fire season The period during which wildfires are likely to occur, spread and do

sufficient damage to warrant organised fire control.

Fire simulator See: Fire training simulator

11


20/33

Wildfire Glossary

Term Definition

Fire spread Development and travel of fire across surfaces.

Fire storm Violent convection caused by a large continuous area of intense wildfireoften characterised by destructively violent surface indrafts, a toweringconvection column, long distance spotting, and sometimes by tornado-likewhirlwinds. (AFAC)

Fire suppressant An additive designed to reduce the surface tension of water and/or to holdwater in suspension thus increasing water's efficiency as a fireextinguishing agent. Suppressants are applied directly to the burning fuels.Also see: Fire retardant. (NZ)

Fire suppressionorganisation

1. The personnel and equipment collectively assigned to the suppressionof a specific fire or group of fires.

2. The personnel responsible for fire suppression within a specified area.

3. The management structure, usually shown in the form of anorganization chart of the persons and groups having specificresponsibilities in fire suppression. (NWCG)

Fire suppression plan See Incident action plan.

Fire tetrahedron An instructional aid in which the sides of the tetrahedron (comprising 4triangular shaped figures) are used to represent the 4 components ofcombustion and flame production process-fuel, heat, oxygen and thechemical chain reaction.

Fire threa t The impact a fire will have on a community.

Fire tower Tower strategically located and manned to detect and report theoccurrence and location of fires. A type of Fire lookout

Fire triangle Diagrammatic expression of the three elements that are necessary for afire to occur. FUEL HEAT OXYGEN. The removal of any one of thesewill extinguish a fire.

Fire weather Weather conditions which influence fire ignition, behaviour, andsuppression. (NWCG)

Fire weather forecast A weather prediction specially prepared for use in wildland fire operationsand prescribed fire. (NWCG)

Fire whirl Spinning vortex column of ascending hot air and gases rising from a fireand carrying aloft smoke, debris, and flame. Fire whirls range in size fromless than one foot to over 500 feet in diameter. Large fire whirls have theintensity of a small tornado. (NWCG)

Fire wind The inflow of air at the fire source caused by the action of convection. It isnot to be confused with a prevailing wind.

First attack See: Initial attackFixed wing aircraft A heavier than air aircraft which obtains lift for flight by forward motion of

wings through the air.

Flame angle The angle of the flame in relation to the ground, caused by wind directionor the effect of a slope.

Flame depth The depth of the zone within which continuous flaming occurs behind thefire edge.

Flame height The average maximum vertical extension of flames at the leading edge ofthe fire front. Occasional flashes that rise above the general level of flamesare not considered. This distance is less than the flame length if flamesare tilted due to wind or slope. (NWCG)

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21/33

Wildfire Glossary

Term Definition

Flame length The distance between the flame tip and the midpoint of the flame depth atthe base of the flame (generally the ground surface), an indicator of fireintensity. (NWCG)

Flammability The ease with which a substance is set on fire.

Flammable Capable of being ignited and of burning with a flame.

Flank attack Obtaining control of a fire by attacking its side/s (flank).

Flanks of a fire Those parts of a fires perimeter that are roughly parallel to the maindirection of spread. (NWCG)

Flare up Any sudden acceleration of fire spread, or intensification of fire, or a part ofthe fire. A flare up is of relatively short duration and does not radicallychange existing control plans. (NWCG)

Flash fire A fast moving fire consuming most of the fine fuels available.

Foam Foam is a mass of bubbles formed by mixing air with water and a foamconcentrate specific proportions. It is used as a firefighting agent to form asmothering, cooling and/or ignition preventing layer of the surface over a

fuel.

Foam Class A A mixture of foam concentrate & water specifically formulated forextinguishing wildfires. The foam is biodegradable, non toxic and is usedat very low concentrates. It may be delivered aspirated or non-aspirated.(See also Foam solution).

Foam Class B A foam formulated for application on Class B fires

Foam blanket A layer of foam which forms an insulating and reflective barrier to heat andis used for fuel protection, suppression, and mop-up. (NWCG)

Foam concentrate The concentrated foaming agent as received from the manufacturer which,when added to water, creates a foam solution; use only those approved foruse in wildland fire situations by the authority having jurisdiction. (NWCG)

Foam inductor Equipment consisting of an inlet connection, ejector pump and a dischargeassembly, for the induction of foam concentrate.

Foam solution The mixture of water and foam concentrate.

Forest fire A fire burning mainly in forest and/or woodland.

Forest type A description of the predominant tree species in a forest.

Forward looking infrared(FLIR)

Hand held or aircraft mounted device designed to detect heat differentialsand display them. FLIRs have thermal resolution similar to IR linescanners, but their spatial resolution is substantially less; commonly usedto detect hot spots and flare ups obscured by smoke, evaluate theeffectiveness of firing operations, or detect areas needing mop-up.(NWCG)

Forward rate of spread The speed with which a fire moves in a horizontal direction across thelandscape. (NWCG)

Frontal fire intensity See: Fireline Intensity

Front end loader Earthmoving equipment designed to move loose earth and/or loads intovehicles. A multi-purpose bucket is fitted to articulated arms at the front ofthe vehicle. May be either wheeled or tracked.

Fuel Any material such as grass, leaf litter and live vegetation which can beignited and sustains a fire. Fuel is usually measured in tonnes per hectare.Related Terms: Available fuel, Coarse fuel, Dead fuel, Elevated dead fuel,

Fine fuel Ladder fuels, Surface fuels, Total fine fuel.Fuel age The period of time lapsed since the fuel was last burnt.

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22/33

Wildfire Glossary

Term Definition

Fuel arrangement A general term referring to the spatial distribution and orientation of fuelparticles or pieces. (NWCG)

Fuel array The totality of fuels displayed in a location: fine and coarse, live and dead.(Vic report)

Fuel assessment The estimation or calculation of total and available fuel present in a given

area.

Fuel bed depth Average height of surface fuels contained in the combustion zone of aspreading fire front. (NWCG)

Fuelbreak A natural or manmade change in fuel characteristics which affects firebehaviour so that fires burning into them can be more readily controlled.

Fuelbreak system A series of modified strips or blocks tied together to form continuousstrategically located fuel breaks around land units.

Fuel continuity The degree or extent of continuous or uninterrupted distribution of fuelparticles in a fuel bed thus affecting a fire's ability to sustain combustionand spread. This applies to aerial fuels as well as surface fuels.

Fuel depth The average distance from the bottom of the litter layer to the top of thelayer of fuel, usually the surface fuel.

Fuel load The oven dry weight of fuel per unit area. Commonly expressed as tonnesper hectare. (AFAC). (Also known as fuel loading)

Fuel management Modification of fuels by prescribed burning, or other means. (AFAC)

Fuel model Simulated fuel complex for which all fuel descriptors required for thesolution of a mathematical rate of spread model have been specified.(NWCG)

Fuel modification Manipulation or removal of fuels to reduce the likelihood of ignition and/orto lessen potential damage and resistance to control (e.g., lopping,chipping, crushing, piling and burning).(NWCG)

Fuel moisture content The water content of a fuel expressed as a percent of the oven dry weightof the fuel particle. (%ODW)

Fuel moisture differential A term used to describe the situation where the difference in the moisturecontent between fuels on adjacent areas results in noticeably different firebehaviour on each area.

Fuel map A map showing areas of varying fuel quantities and types and usuallyindicates past fire history.

Fuel profile The vertical cross section of a fuel bed down to mineral earth.

Fuel quantity See: Fuel load.

Fuel reduction burning The planned application of fire to reduce hazardous fuel quantities;undertaken in prescribed environmental conditions within definedboundaries.

Fuel reduction Manipulation, including combustion, or removal of fuels to reduce thelikelihood of ignition and/or to lessen potential damage and resistance tocontrol.

Fuel separation The action of separating fuel for the purpose of providing a mineral earthfirebreak. Also means the actual gap between fuel layers or particles eggap between individual hummock grasses or gap between surface andcanopy fuels

Fuel type An identifiable association of fuel elements of distinctive species, form,

size, arrangement, or other characteristics that will cause predictable rateof spread or difficulty of control under specified weather conditions.(AFAC)

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23/33

Wildfire Glossary

Term Definition

Fuel weight See Fuel load.

General origin area The larger area where the fire started that is readily identifiable based onmacro scale indicators and witness statements. (NWCG)

Going fire Any wildfire on which suppression action has not reached an extensivemop up stage. (NWCG)

Grass fire Any fire in which the predominant fuel is grass or grass like. (NWCG)

Grassland curing The proportion of dead material in grasslands usually increases oversummer as tillers die off and dry out, increasing the risk of grassland fire.

Grid ignition A method of lighting prescribed fires where ignition points are setindividually at a predetermined spacing through an area.

Ground crew See: Hand crew.

Ground fire Fire that consumes the organic material beneath the surface litter ground,such as a peat fire. (NWCG)

Groun d fuels All combustible materials below the surface litter, including duff, roots, peat

and saw dust dumps that normally support a glowing combustion withoutflame. Synonym: Subsurface Fuels. Note: Aerial, Surface and LadderFuels.

Habitat The place in which an animal or plant lives.

Hand crew A fire suppression crew trained and equipped to fight fire with hand tools.

Hand line A fireline constructed with hand tools. (NWCG) (Wildfire context)

Hang up A situation in which a tree is lodged in another and prevents it from fallingto the ground.

Hand trail See Hand line.

Hazard A source of potential harm or a situation with potential to cause loss.

Hazard reduction See: Fuel Management

Head See: Head Fire

Head attack Directly knocking down the head of a fire. Recommended only for lowintensity fires where firefighters can be sure that the fire will not flare upunexpectedly.

Head fire The part of a fire where the rate of spread, flame height and intensity aregreatest, usually when burning downwind or upslope.

Heat exhaustion A form of shock, due to depletion of body fluids resulting fromoverexposure to a hot environment.

Heat stress Illness caused by the body overheating.Heat stroke A life-threatening condition that develops when the bodys temperature-

regulating and cooling mechanisms are overwhelmed and body systemsbegin to fail.

Heavy fuels See: Coarse fuels.

Heel See: Rear.

Heel fire See: Backing Fire.

Helibase (HB) A location for parking, refuelling and maintenance of helicopters operatingin support of an incident.

Helicopter A form of heavier-than-air, rotor-wing aircraft whose lift is produced by

engine-driven rotors which behave as if they were both propellers andwings.

15


24/33

Wildfire Glossary

Term Definition

Helipad (HP) A designated location which meets specific requirements for a helicopterto take off and land.

Helitack crew An initial attack crew specially trained in the tactical and logistical use ofhelicopters for fire suppression.

Heli torch An aerial ignition device hung from or mounted on a helicopter to disperse

ignited lumps of gelled gasoline. Used for backfires, burnouts, orprescribed burns. (NWCG)

High intensity fire Fires with an average intensity greater than 3000 kW.m-1

and flameheights greater than 3 m, causing complete crown scorch or possiblycrown fires in forests. Uncontrollable by direct attack. The term is alsoapplied to stationary fires burning in very high fuel loads (such as loggingslash).

Hold over fire See: Sleeper

Hop over See: Breakaway.

Hose bandage A means of affecting a temporary repair to a canvas or synthetic hose.

Hose strangler A crimping device for stopping the flow of water in a hose.

Hot Refueller A trained person responsible for the operation of the equipment for thehot refuelling of helicopters.

Hot spot A particularly active part of a fire.

Humus Layer of decomposed organic matter on the forest floor beneath thefermentation layer and directly above the soil. It is that part of the duff inwhich decomposition has rendered vegetation unrecognizable and mixingof soil and organic matter is underway. See Also: Duff & Litter

Hygrometer An Instrument which measures the humidity in the air.

Ignition The beginning of flame production or smouldering combustion; the starting

of a fire.

Ignition p attern The manner in which a prescribed burn, backfire, or burnout is set,determined by weather, fuel, ignition system, topographic and other factorshaving an influence on fire behaviour and the objective of the burn.

Ignition sour ce A source of energy sufficient to initiate combustion.

Incendiary A burning compound or metal used to produce intense heat or flame, like abomb.

Incendiary device Device designed and used to start a fire.

Incident Any unplanned event requiring emergency intervention. (AIIMS)

Incident Action Plan(IAP) Is the plan used to describe the incident objectives, strategies, resourcesand other information relevant to the control of an incident. (AIIMS)

Incident control See: Incident management

Incident control system(ICS)

A command structure to systematically and logically manage suppressionof emergency incidents including wildfires, from small, simple incidents tolarge, difficult or multiple situations. It is designed to develop in modularfashion from the top (Incident Controller) downwards. Refer NIMS, AIIMS,CIMS

Incident Controller The individual responsible for the management of all incident controlactivities across a whole incident (AIIMS)

Incident m anagement The process of controlling the incident and coordinating resources. (EMA)

Incident ManagementTeam (IMT)

The group of incident management personnel comprising the IncidentController, and the personnel he or she appoints to be responsible for thefunctions of Operations, Planning and Logistics. (AIIMS)

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Wildfire Glossary

Term Definition

Incident o bjective An incident objective is a goal statement indicating the desired outcome ofthe incident. Incident objectives guide the development of the IncidentAction Plan and must reflect the policies and needs of the control authorityand supporting agencies. All factors affecting the incident and its potentialimpact must be considered before determining the objective. (AIIMS)

Incident strategies The incident strategies will be developed from the incident objectives andwill describe how the Incident Management Team plans to resolve theincident. There is a requirement for strategies to be developed throughoutthe incident and they should be reviewed for each operational period.(AIIMS)

Indirect attack A method of suppression in which the control line is located someconsiderable distance away from the fire's active edge. Generally done inthe case of a fast-spreading or high-intensity fire and to utilize natural orconstructed firebreaks or fuelbreaks and favourable breaks in thetopography. The intervening fuel is usually backfired; but occasionally themain fire is allowed to burn to the line, depending on conditions.(NWCG)

Induced wind See: Fire wind.

Infrared scanning Use of an optical-electronic system for identifying or obtaining imagery ofthermal infrared radiation to detect non-smoking fires or fire perimetersthrough smoke.

Instability Instability The tendency for air parcels to accelerate when they aredisplaced from the

wildfire glossary indexed 2008

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