Fuel Characteristic Classification System version 3.0: technical documentation

Abstract

DisclaimerThe Fuel Characteristic Classification System (FCCS) is in the public domain and the recipient may not assert any proprietary rights thereto or represent them to anyone as other than government-produced programs. The FCCS software is provided "as is" without warranty of any kind, including but not limited to the implied warranties of merchantability and fitness for a particular purpose. The user assumes all responsibility for the accuracy and suitability of these programs for a specific application.The use of trade or firm names in this publication is for reader information and does not imply endorsement by the U.S. Department of Agriculture of any product or service. The views and opinions of authors expressed herein do not necessarily state or reflect those of the U.S. government or any agency thereof. Cover photographs:Fuelbeds are structurally complex and vary widely in their physical attributes and potential fire behavior. These grassland, shrubland, and forest examples illustrate a diversity of vegetation and fuels: (1) grassland in southeastern Oregon, The flexible design of FCCS allows users to represent the structural complexity and diversity of fuels created through natural processes (e.g., forest succession and disturbance) and management activities (e.g., forest harvesting and fuels reduction).Each fuelbed is organized into six strata, including canopy, shrubs, herbaceous vegetation, woody fuels, litter-lichen-moss, and ground fuels. Strata are further divided into categories and subcategories. Fuelbeds representing common fuel types throughout much of North America are available in the FCCS reference library. Users may select an FCCS fuelbed to represent their specific project or customize a fuelbed to reflect actual site conditions. The FCCS reports the following results: (1) fuel characteristics by fuelbed, stratum, category, and subcategory; (2) surface fire behavior (i.e., reaction intensity, rate of spread, and flame length); and (3) FCCS fire potential ratings of surface fire behavior, crown fire behavior, and available fuels. With its large fuels data set and ability to represent a wide variety of fuel conditions, the FCCS has numerous applications, from small-scale fuel reduction projects to large-scale emissions and carbon assessments. This report provides technical documentation of the required inputs and computations in the FCCS.

Generation of a global fuel data set using the Fuel Characteristic Classification System

“…For example, FCCS calculates three fuel potentials (surface fire behavior potential, crown fire potential, and available fuel potential) using benchmark environmental variables, which can be used to evaluate fire danger based solely on fuel characteristics Prichard et al, 2013). Also, specific environmental variables (fuel moisture, slope, and wind speed) can be assigned to calculate expected surface fire behavior for different weather conditions, as it provides results on rate of spread, flame length, and reaction intensity.…”

“…4. The value of 40 % was assigned because that is the threshold used in FCCS to decide if canopy fire spread can occur (Prichard et al, 2013). The 70 % threshold was assigned to divide the rest of the existing canopy percentage in two equal parts.…”

“…FCCS estimates the amount of total biomass and carbon load per stratum based on the parameters assigned to each strata and a set of biomass equations for different types of vegetation (Prichard et al, 2013). This biomass is used for the calculation of the available fuel potential and biomass consumption in the Consume Module inside FFT (http: //www.fs.fed.us/pnw/fera/fft/consumemodule.shtml, last access: January 2016).…”

Quantifying Ladder Fuels: A New Approach Using LiDAR

“…Methods to directly quantify ladder fuels using a key in the field are rare [18][19][20]. Menning and Stephens' approach was semi-qualitative, and classified ladder fuels into one of five types, which proved to be highly variable even within the four adjacent subplots [18].…”

“…Ladder fuels are difficult to account for in the field, and few studies have attempted to develop an explicit, field-based measurement procedure (but see [18][19][20]). Instead, canopy base height (CBH) and a fuel model (sometimes with an adjustment of fire behavior) are used as a surrogate for ladder fuels [21].…”