BC Wildfire Service

Common Wildfire Terminology

Fire Season—The period(s) of the year during which fires are likely to start, spread and damage values-at-risk sufficient to warrant organized fire suppression. It is a period of the year set out and commonly referred to in fire prevention legislation.

Wildfire—An unplanned fire, including unauthorized human-caused fires, occurring on forest or range lands, burning forest vegetation, grass, brush, scrub, peat lands or a prescribed fire set under regulation which spreads beyond the area authorized for burning.

Wildfire Causes—For a wildfire to ignite and burn, sufficient of the following must be present: fuel, oxygen and heat. The cause of a wildfire depends on the source of the heat that ignited a fuel source: natural (vast majority of which are ignited by lightning) and human-caused (including the use of engines or vehicles, dropping burning substances or any other activity that can produce a spark or sufficient heat).

Wildland Urban Interface (WUI)—An area where any combustible forest fuel is found adjacent to homes, farm structures or other outbuildings and may occur where development meets fuels at a well-defined boundary or where they intermingle with no defined boundary.

Fire Risk—Fire risk combines the probability of fire occurrence with the expected impacts from a fire.

Fire Rank—A numerical value used to communicate a summarized visual assessment of fire behaviour.

Fire Danger Rating

Low—Fires may start easily and spread quickly but there will be minimal involvement of deeper fuel layers or larger fuels.

Moderate—Forest fuels are drying and there is an increased risk of surface fires starting.

High—Forest fuels are very dry and the fire risk is serious. New fires may start easily, burn vigorously and challenge suppression efforts.

Extreme—Forest fuels are extremely dry and fire risk is very serious. New fires will start easily, spread rapidly and challenge suppression efforts.

Fire Stage of Control

Out of Control—Describes a wildfire that is not responding (or only responding on a limited basis) to suppression action, such that the perimeter spread is not being contained.

Being Held—Indicated that, with the resources currently committed to the fire, sufficient suppression action has been taken that the fire is not likely to spread beyond existing/predetermined boundaries under the prevailing and forecasted conditions.

Under Control—The fire has received sufficient suppression action to ensure no further spread of the fire.

Out—The fire has been extinguished.

Fire Response Type

Full Response—The wildfire requires immediate initial attack and/or sustained suppression action until the fire is declared “out”.

Modified Response—The wildfire is managed using a combination of suppression techniques, including direct and indirect attack, and monitoring to steer, contain or otherwise manage fire activity within a pre-determined perimeter (to minimize costs and/or damage and to maximize benefits from the fire).

Monitored—The wildfire is observed and assessed to determine the appropriate response option to minimize social disruption and/or significant impacts on values and resources, while achieving beneficial ecological, economic or resource management objectives.

Wildfire Crews

Initial Attack (IA) Crews—IA firefighters operate as part of a three‐ or four‐person crew and are usually the first on scene of a new wildfire. They work quickly to set up water pumps, remove fuel from the fire’s path and dig guards to control or extinguish the blaze.

Unit Crews—Unit crews work in 20‐person packs and are specialized to perform sustained action when a fire has grown beyond IA resources. They establish pump and hose lines, dig fire guards, burn off fuel from the fire’s path and use chainsaws to cut fuel breaks and remove danger trees.

Parattack Crews—Parattack crews parachute to fires in hard‐to‐access locations from fixed wing aircraft. These crews are based out of the PGFC in the Fort St. John and Mackenzie zones and can respond anywhere in the province within two hours.

Rapattack Crews—Rapattack crews rappel and/or hoist from rotary‐wing aircraft (eg. helicopters) in order to perform IA fire suppression on (often) otherwise inaccessible wildfires. This program is based out of the Kamloops Fire Centre in Salmon Arm, which is centrally located for the majority of fires requiring rapattack response.