Function fuel_stratification
provides a stratification of the stand into understory and canopy strata. Function fuel_FCCS
calculates fuel characteristics from a forest
object following an adaptation of the protocols described for the Fuel Characteristics Classification System (Prichard et al. 2013). Function fuel_windAdjustmentFactor
determines the adjustment factor of wind for surface fires, according to Andrews (2012). Function fuel_cohortFineFMC
calculates the fuel moisture content of leaves and twigs of each cohort, from the results of soil water balance.
fuel_stratification(object, SpParams, gdd = NA,
heightProfileStep = 10.0, maxHeightProfile = 5000.0,
bulkDensityThreshold = 0.05)
fuel_FCCS(object, ShrubCover, CanopyCover, SpParams, cohortFMC = as.numeric(c()),
gdd = NA, heightProfileStep = 10, maxHeightProfile = 5000,
bulkDensityThreshold = 0.05)
fuel_cohortFineFMC(spwb, x)
fuel_windAdjustmentFactor(topShrubHeight, bottomCanopyHeight, topCanopyHeight,
canopyCover)
An object of class forest
Total shrub cover (in percent) of the stand.
Total canopy cover (in percent) of the stand.
A data frame with species parameters (see SpParamsMED
).
A numeric vector of (actual) fuel moisture content by cohort (e.g. taken from the result of fuel_cohortFineFMC
).
Growth degree-days.
Precision for the fuel bulk density profile.
Maximum height for the fuel bulk density profile.
Minimum fuel bulk density to delimit fuel strata.
Object returned by function spwb
.
Shrub stratum top height (in m).
Canopy base height (in m).
Canopy top height (in m).
Canopy percent cover.
An object of class spwbInput
.
Function fuel_FCCS
returns a data frame with five rows corresponding to fuel layers: canopy
, shrub
, herb
, woody
and litter
. Columns correspond fuel properties:
w
: Fine fuel loading (in kg/m2).
cover
: Percent cover.
hbc
: Height to base of crowns (in m).
htc
: Height to top of crowns (in m).
delta
: Fuel depth (in m).
rhob
: Fuel bulk density (in kg/m3).
rhop
: Fuel particle density (in kg/m3).
PV
: Particle volume (in m3/m2).
beta
: Packing ratio (unitless).
betarel
: Relative packing ratio (unitless).
etabetarel
: Reaction efficiency (unitless).
sigma
: Surface area-to-volume ratio (m2/m3).
pDead
: Proportion of dead fuels.
FAI
: Fuel area index (unitless).
h
: High heat content (in kJ/kg).
etaF
: Flammability modifier (between 1 and 2).
RV
: Reactive volume (in m3/m2).
MinFMC
: Minimum fuel moisture content (as percent over dry weight).
MaxFMC
: Maximum fuel moisture content (as percent over dry weight).
Function fuel_stratification
returns a list with the following items:
surfaceLayerBaseHeight
: Base height of crowns of shrubs in the surface layer (in cm).
surfaceLayerTopHeight
: Top height of crowns of shrubs in the surface layer (in cm).
understoryLAI
: Cumulated LAI of the understory layer (i.e. leaf area comprised between surface layer base and top heights).
canopyBaseHeight
: Base height of tree crowns in the canopy (in cm).
canopyTopHeight
: Top height of tree crowns in the canopy (in cm).
canopyLAI
: Cumulated LAI of the canopy (i.e. leaf area comprised between canopy base and top heights).
Function fuel_cohortFineFMC
returns a list with three matrices (for leaves, twigs and fine fuels). Each of them contains live moisture content values for each day (in rows) and plant cohort (in columns).
Function fuel_windAdjustmentFactor
returns a value between 0 and 1.
Details are described in a vignette.
Andrews, P. L. 2012. Modeling wind adjustment factor and midflame wind speed for Rothermel<U+2019>s surface fire spread model. USDA Forest Service - General Technical Report RMRS-GTR:1<U+2013>39.
Prichard, S. J., D. V Sandberg, R. D. Ottmar, E. Eberhardt, A. Andreu, P. Eagle, and K. Swedin. 2013. Classification System Version 3.0: Technical Documentation.
Reinhardt, E., D. Lutes, and J. Scott. 2006. FuelCalc: A method for estimating fuel characteristics. Pages 273<U+2013>282.
# NOT RUN {
#Load example plot plant data
data(exampleforest)
#Default species parameterization
data(SpParamsMED)
#Show stratification of fuels
fuel_stratification(exampleforest, SpParamsMED)
#Calculate fuel properties according to FCCS
fccs = fuel_FCCS(exampleforest, 50,100, SpParamsMED)
fccs
fuel_windAdjustmentFactor(fccs$htc[2], fccs$hbc[1], fccs$htc[1], fccs$cover[1])
# }
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