Compute the wildfire exposure metric with custom transmission distances

For advanced users. Adjust the transmission distances from the defaults used in fire_exp().

Usage

fire_exp_adjust(hazard, tdist, no_burn)

Arguments

hazard

a SpatRaster that represents hazardous fuels for the transmission distance specified in tdist

tdist

Numeric, transmission distance in meters

no_burn

(Optional) SpatRaster that represents the non-burnable landscape. Any cells that cannot receive wildfire (e.g. open water, rock) and any cells that are not natural (e.g. built environment, irrigated agricultural areas) should be of value 1, all other cells should be NODATA. This parameter should be provided if preparing data for fire_exp_validate()

Value

SpatRaster object of exposure values

Details

If the transmission distances from the wildfire exposure literature are not representative of the wildland fuels in your area of interest, this function can be used to change the transmission distance to a custom distance. It is highly recommended that any exposure layers produced with this function are validated with observed fire history using the fire_exp_validate() function.

Spatial Reference

The exposure raster will be returned in the same CRS as the input hazard layer. A crs must be defined if the outputs will be used in other functions in this package.

Spatial resolution

For a specified transmission distance, the spatial resolution must be at least 3 times finer. For example, for a transmission distance of 300 meters the input data should have a resolution of 100 meters or finer.

See also

fire_exp() for background information

Examples

# read example hazard data
hazard_file_path <- "extdata/hazard.tif"
hazard <- terra::rast(system.file(hazard_file_path, package = "fireexposuR"))

# compute long range exposure with custom disance of 800 m
exposure800 <- fire_exp_adjust(hazard, tdist = 800)