The BC Wildfire Act and Regulation require a fuel hazard assessment following any industrial or prescribed activities within or adjacent to (i.e., within one kilometer) forest or grass lands. Traditional fuel hazard assessments are a complex process, involving: (1) field sampling to quantify the amount (or loading) of fuels left on the forest floor; and (2) analysis of the data to determine the hazard level. In Canada, forest fuels are reported in either kilograms per square meter (kg/m^2), or Tonnes per hectare (Tph).
A simplified approach to quantifying fuel loading is to visually compare what exists in the forest with what is shown in calibrated photos; the photos must be taken in similar forest types. In BC, very few calibrated photos are available for the Interior Douglas-Fir (IDF) Biogeoclimatic (BEC) zone. The photo library presented here is intended to fill that gap. It covers a range of Tph values (Between 1-99), in both pre- and post-harvest conditions.
These photos have been calibrated using line intersect transects to quantify Tph. The line intersect method (Van Wagner 1968, Brown 1974, Van Wagner 1982) is the most common and widely accepted method used by wildfire professionals to quantify forest floor fuel loading. The method we implement involves nested sub-transects, ranging from 1m for 1 hr fuels, 2m for 10 hr fuels, 4m for 100 hr fuels, and 15m for 1000 hr fuels. Please refer to the Fuel Hazard Abatement section in the "Services" menu for details about this process.
Notably, the Wildfire Act and Regulation is primarily concerned with increasing the potential for fire spread. Therefore, only fine surface fuels (i.e., 1-100 hr fuels that are ≤7.5 cm in diameter) are targeted for assessment and abatement. Using our method, only the nested 1m, 2m and 4m transects are required to quantify this "fine" fuel loading. We perform the additional 15m transects when coarse woody debris are important to quantify for other reasons (e.g., wildlife habitat, resident fire intensity values, etc.). For these reasons, photos from both 15m and 4m transects have been included in the photo library. All photos will report the fine fuel loading while some will include the total fuel loading, which adds the coarse woody debris (i.e., 1000 hr fuels >7.5cm diameter) to Tph calculations.