JIBC Wildland Fire Suppression — Questions and Answers
Question 1: The fire behaviour triangle consists of fuel, weather, and:
- Ignition source
- Topography (Correct answer)
- Humidity
- Wind speed
Correct answer: Topography
Wildland fire behaviour is governed by the triangle of fuel (type, arrangement, moisture), weather (temperature, relative humidity, wind), and topography (slope, aspect, terrain features). Ignition source starts the fire but does not drive its ongoing behaviour.
Question 2: In wildland fire suppression, a 'crowning' fire is MOST dangerous because:
- It burns only in dry grass and is difficult to locate at night
- It spreads through the tree canopy and can move faster than firefighters can escape (Correct answer)
- It produces minimal visible smoke, making aerial spotting difficult
- It is always caused by lightning and cannot be predicted by weather models
Correct answer: It spreads through the tree canopy and can move faster than firefighters can escape
Crown fires travel through the upper canopy at speeds that can far exceed ground fire rates—sometimes outpacing even vehicles on roads. They dramatically reduce firefighter safety margins and are a primary reason for emergency escape route and safety zone planning.
Question 3: When constructing a hand guard line around a wildland fire, the correct technique is to:
- Scrape all vegetation and duff down to bare mineral soil along the line (Correct answer)
- Cut and stack green vegetation on the fire side of the line as a fuel break
- Apply water to the unburned side of the line to create a wet buffer
- Build the line just inside the active flame front for maximum efficiency
Correct answer: Scrape all vegetation and duff down to bare mineral soil along the line
An effective guard line removes all combustible material—vegetation, duff, leaf litter—down to bare mineral soil, eliminating the fuel pathway. Building inside the flame front is unsafe; applying water without a mineral soil line is inadequate for a lasting fuel break.
Question 4: A wildland firefighter observes that the wind has shifted and the fire is now burning toward their position. The FIRST action they should take is:
- Begin suppression operations on the advancing flame front
- Move to a pre-identified safety zone via the designated escape route immediately (Correct answer)
- Radio dispatch for an air tanker drop before repositioning
- Deploy a fire shelter in place and wait for the fire to pass
Correct answer: Move to a pre-identified safety zone via the designated escape route immediately
The 10 Standard Firefighting Orders and LCES (Lookouts, Communications, Escape Routes, Safety Zones) framework require immediate retreat to a safety zone when the fire situation changes and positions become unsafe. Suppression, air support requests, and shelter deployment are secondary to immediate escape.
Question 5: The Canadian Forest Fire Danger Rating System (CFFDRS) Fire Weather Index (FWI) primarily measures:
- The probability of a human-caused ignition on a given day
- The potential intensity and spread rate of a wildland fire based on weather inputs (Correct answer)
- The number of active fires within a defined geographic zone
- The moisture content of large woody debris greater than 7 cm in diameter
Correct answer: The potential intensity and spread rate of a wildland fire based on weather inputs
The FWI system uses temperature, relative humidity, wind speed, and rainfall to produce indices—including spread rate, fuel consumption, and fire intensity—that describe potential fire behaviour under current weather conditions. It does not count active fires or measure specific fuel classes directly.
Question 6: Aspect (the compass direction a slope faces) affects wildland fire behaviour primarily because:
- South-facing slopes in the northern hemisphere receive more solar radiation, producing drier fuels (Correct answer)
- North-facing slopes channel wind into fire-accelerating terrain traps more often
- East-facing slopes are always closer to ignition sources from lightning storms
- West-facing slopes receive rainfall last during frontal passage, keeping fuels wetter
Correct answer: South-facing slopes in the northern hemisphere receive more solar radiation, producing drier fuels
In the northern hemisphere, south-facing slopes receive more direct solar radiation throughout the day, which dries fuels and raises temperatures relative to north-facing slopes. This typically produces higher fire danger and faster spread rates on southern exposures.
JIBC Wildland Fire Suppression
The fire behaviour triangle consists of fuel, weather, and: