gfmcRaster {cffdrs}

Grass Fuel Moisture Raster Calculation

Description

Calculation of the Grass Fuel Moisture Code. This calculates the moisture content of both the surface of a fully cured matted grass layer and also an equivalent Grass Fuel Moisture Code. All equations come from Wotton (2009) as cited below unless otherwise specified.

Usage

gfmcRaster(input, GFMCold = 85, time.step = 1, roFL = 0.3, out = "GFMCandMC")

Arguments

input

[SpatRast stack]

temp	(required)	Temperature (centigrade)
rh	(required)	Relative humidity (%)
ws	(required)	10-m height wind speed (km/h)
prec	(required)	1-hour rainfall (mm)
isol	(required)	Solar radiation (kW/m^2)

GFMCold

GFMC from yesterday (double, default=85)

time.step

The hourly time steps (integer hour, default=1)

roFL

Nominal fuel load of the fine fuel layer (kg/m^2 double, default=0.3)

out

Output format (GFMCandMC/MC/GFMC/ALL, default=GFMCandMC)

Value

Returns a spatrast stack of either MC, GFMC, GFMC and MC or All

References

Wotton, B.M. 2009. A grass moisture model for the Canadian Forest Fire Danger Rating System. In: Proceedings 8th Fire and Forest Meteorology Symposium, Kalispell, MT Oct 13-15, 2009. Paper 3-2. https://ams.confex.com/ams/pdfpapers/155930.pdf

Examples

set.seed(5123)
test_gfmc_r <- rast(
  nrows = 25,
  ncols = 25,
  crs = "EPSG:3402",
  resolution = 100,
  ymin = 5652012,
  ymax = 5652012 + (25 * 100),
  xmin = 565550,
  xmax = 565550 + (25 * 100),
  names = "temp",
  vals = sample(x = 19:27, size = 25 * 25, replace = TRUE)
)

test_gfmc_r <- c(
  test_gfmc_r,
  setValues(test_gfmc_r, sample(x = 0:3, size = 25 * 25, replace = TRUE)),
  setValues(test_gfmc_r, sample(x = 10:20, size = 25 * 25, replace = TRUE)),
  setValues(test_gfmc_r, sample(x = 30:70, size = 25 * 25, replace = TRUE)),
  setValues(
    test_gfmc_r,
    sample(
      x = (5:950) / 1000,
      size = 25 * 25,
      replace = TRUE
    )
  )
)
names(test_gfmc_r) <- c("temp", "prec", "ws", "rh", "isol")

gfmcRaster(test_gfmc_r, out = "GFMCandMC")