Fire regime is defined as the kind of fire activity or pattern of fire that generally characterize a given area. A fire
regime analysis helps to evaluate ecological elements of wildfire. Combinations of components can be evaluated to identify
areas on the landscape that are fire driven and fire dependant.
Fire Regime Analysis Components
- Fire frequency
The number of fires that occur per unit time and area Fire season
The period(s) of the year during which fires start and spread sufficient to warrant organized fire suppression
- Fire size
The total area burned and size class distribution for a given area
- Fire severity
The combined ground and above ground effects resulting from smouldering and flaming combustion on either a wildfire or prescribed
fire site as manifested in various fire behavior characteristics (i.e., fire intensity, flame height and length, residence
and burnout-times, etc.), this is inferred after-the-fact from the fire impact(s).
- Fire intensity
The rate of heat energy release in kilowatts per meter. Determines fire effects and difficulty of control
- Fire type
The class of wildland fire based on the fuel layer(s) involved in the combustion process (ground, surface, and crown).
- Burn Probability
The probability, as expressed by a percentage, that a given area of flammable fuel will burn in a given period of time.
The following figure demonstrates an example of a fire regime analysis output identifying areas on the landscape where
fire may have varying levels of ecological benefit. A link between a wildfire threat assessment and fire regime analysis
is useful in determining the level and location of ecological constraints and benefit. A clear scope and understanding of
objectives and outputs are required to best determine which combinations and number of components a person wishes to include
in the fire regime analysis process.
- Ecological Benefit (severe constraints): Fire is not desired
- Ecological Benefit (some constraints): Fire is restricted
- Ecological Benefit (no contraints): Fire is desired
- No Ecological Benefit: Fire is not restricted
Updated: Apr 27, 2004