Create a slope-based conductance surface — make_conductance

Masks a DEM to an optional road/pathway mask and creates a slope conductance surface using leastcostpath.

Usage

make_conductance_surface(
  dem,
  road_mask = NULL,
  resolution = NULL,
  method = "slope",
  lcp_cost_function = "tobler",
  lcp_neighbours = 16,
  lcp_crit_slope = 12,
  lcp_max_slope = NULL,
  ...
)

Arguments

dem: Elevation raster.
road_mask: Optional road/pathway mask.
resolution: Optional target DEM resolution before conductance creation.
method: Conductance method. Currently only "slope" is implemented.
lcp_cost_function: Character string or function passed to leastcostpath::create_slope_cs().
lcp_neighbours: Neighbourhood passed to leastcostpath::create_slope_cs(). Use 4, 8, 16, 32, 48, or a custom matrix accepted by leastcostpath.
lcp_crit_slope: Numeric critical slope passed to leastcostpath::create_slope_cs().
lcp_max_slope: Optional numeric maximum slope passed to leastcostpath::create_slope_cs().
...: Additional named arguments passed to leastcostpath::create_slope_cs(), such as exaggeration.

Value

A leastcostpath conductance surface object.

Examples

dem <- terra::rast(nrows = 5, ncols = 5, xmin = 0, xmax = 5, ymin = 0, ymax = 5,
  vals = 1, crs = "EPSG:3857")
make_conductance_surface(dem, lcp_neighbours = 8)
#> calculating slope...
#> Applying tobler cost function
#> Class:  conductanceMatrix
#> cost function:  tobler
#> neighbours: 8
#> resolution: 1 1 (x, y)
#> max slope: NA
#> exaggeration: FALSE
#> critical slope: NA
#> SpatRaster dimenions:  5 5 25 (nrow, ncol, ncell)
#> Matrix dimensions:  25 25 (nrow, ncol)
#> crs: +proj=merc +a=6378137 +b=6378137 +lat_ts=0 +lon_0=0 +x_0=0 +y_0=0 +k=1 +units=m +nadgrids=@null +wktext +no_defs
#> extent: 0 5 0 5 (xmin, xmax, ymin, ymax)