Extract the river valley from the DEM

The slope of the digital elevation model (DEM) is used as friction (cost) surface to compute the cost distance from any grid cell of the raster to the river. A characteristic value (default: the mean) of the cost distance distribution in a region surrounding the river (default: a buffer region of 2 km) is then calculated, and used to threshold the cost-distance surface. The resulting area is then "polygonized" to obtain the valley boundary as a simple feature geometry.

Usage

get_valley(dem, river, bbox = NULL)

Arguments

dem

Digital elevation model of the region

river

A simple feature geometry representing the river

bbox

Bounding box defining the extent of the area of interest

Value

River valley as a simple feature geometry