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Rasterize a stream network onto a DEM grid

Source: R/fl_stream_rasterize.R
fl_stream_rasterize.Rd

Burns stream line features onto the grid defined by a template raster. Each stream cell receives the value of field (typically upstream contributing area or channel width); non-stream cells are NA.

Usage

fl_stream_rasterize(streams, template, field = "channel_width")

Arguments

streams

An sf linestring object with the stream network.

template

A SpatRaster that defines the output grid (extent, resolution, CRS). Typically the DEM.

field

Character. Column name in streams to use as the cell value. Must be numeric. Default "channel_width".

Value

A SpatRaster with the same grid as template. Stream cells carry the value of field; all other cells are NA.

Details

Rasterization uses terra::rasterize() with touches = FALSE (only cells whose centre falls on a stream line are burned). When multiple features overlap a cell, the maximum value is kept.

The output CRS matches template. If streams and template have different CRS, streams is reprojected to match.

Examples

dem <- terra::rast(system.file("testdata/dem.tif", package = "flooded"))
streams <- sf::st_read(
  system.file("testdata/streams.gpkg", package = "flooded"),
  quiet = TRUE
)
stream_r <- fl_stream_rasterize(streams, dem, field = "upstream_area_ha")
terra::plot(stream_r, main = "Upstream area (ha)")