>>> Part 2. Historical Perspectives

A variety of remote sensing datasets have been used to map the extent affected by fires and to evaluate the active and post-fire characteristics associated with numerous ecological and societal effects. The technology and data that is often applied to these issues are used by a wide variety of different people, ranging from academics, BAER teams, incident commanders, to local land managers. As such, it becomes very important to use consistent and accurate terminology to describe how to both use the data and to describe what the analysis of that data means.

In the analysis of fire-remote sensing imagery, five common terms exist:

Fire Intensity is commonly used to describe the fire behavior and is commonly evaluated via measures such as the fire front rate of spread and the energy flux associated with the combustion of the fuel (Davis 1959; Whelan 1995)

 

Fire Severity is widely used to describe measure that incorporate both active fire behavior and immediate post-fire effects on the environment (Lentile et al 2006).

 

Burn Severity is widely used to describe ecological affects that can range form minutes to years post-fire.

 

First-Order Fire Effects is widely used by the fire-modeling community to describe the direct and immediate fire-effects. Typical First-Order Fire Effects could include the combustion of fuels and the production of emissions.

 

Second-Order Fire Effects refer to the indirect effects of fire on the environment and can include measures such as impacts on air and water quality, erosion, and succession.

Several studies have clearly been confused as to when each term is appropriate, with some studies switching between these different terms in the same document.

A further area of confusion arises when different people have different management objectives. For instance, a soil scientist is likely to have quite different metrics of intensity and severity than say a wildlife biologist or a timber company.

As such this resource synthesizes the current available literature with the aim to clarify what each of these terms mean. For more detailed information, please refer to our peer-reviewed review paper in the International Journal of Wildland Fire.