Provides a method for preprocessing sf/terra polygons or raster/terra rasters for calculating fetch using get_fetch(). When provided raster data, the default behavior is to treat all NA cells as water cells and all non NA cells as land. If you want to specify a different value for water cells, use the water_value argument to specify the grid cells that represent water. Returns a binary landwater SpatRaster with land values of 0 and water values of 1. A water value should be specified to indicate which pixel value should represent water in the final raster. The rest of the pixels will indicate land cells.
Arguments
- r
sf POLYGON/MULTIPOLYGON, terra SpatVect POLYGON, SpatRaster, RasterLayer, or a file path (character) to a vector/raster data file. Data must be on a projected CRS.
- water_value
numeric, value indicating the value of the water cells within the input raster. If a sf/terra polygon is given, this argument is ignored. Default is NA, such that NA cells are treated as water cells and all other cells are land cells.
- res
numeric resolution for template raster. If a polygon is given, the polygon must be rasterized at a specific resolution. This argument is ignored if a raster/terra raster is given. Default is 2000, which will rasterize polygons onto a grid with a grid cell resolution of 2000 x 2000.
- verbose
logical, whether messages should be printed. Default is TRUE, so messages will print.
Examples
if (FALSE) {
# Create a binary landwater SpatRaster from a sf polygon at a 2000m x 2000m resolution
lw <- fetchr::get_landwater(
r = fetchr::land_vect,
res = 2000
)
}