r.carve.1grass man page

r.carve — Generates stream channels.
Takes vector stream data, transforms it to raster and subtracts depth from the output DEM.


raster, hydrology


r.carve --help
r.carve [-n] raster=name vector=name output=name  [points=name]   [width=float]   [depth=float]   [--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]



No flat areas allowed in flow direction


Allow output files to overwrite existing files


Print usage summary


Verbose module output


Quiet module output


Force launching GUI dialog


raster=name [required]

Name of input raster elevation map

vector=name [required]

Name of input vector map containing stream(s)
Or data source for direct OGR access

output=name [required]

Name for output raster map


Name for output vector map for adjusted stream points


Stream width (in meters)
Default is raster cell width


Additional stream depth (in meters)


r.carve accepts vector stream data as input, transforms them to raster, and subtracts a default-depth + additional-depth from a DEM. If the given width is more than 1 cell, it will carve the stream with the given width. With the -n flag it should eliminate all flat cells within the stream, so when and if the water gets into the stream it will flow. The points option generates x,y,z for points which define the stream with the z-value of the bottom of the carved-in stream. These points can then be combined with contours to interpolate a new DEM with better representation of valleys.


r.carve does not create a depressionless DEM because many depressions are in flat areas and not in the streams.


North Carolina sample dataset:

g.region raster=elevation -p
r.carve rast=elevation vect=streams out=carve_dem width=20 depth=5

Known Issues

The module does not operate yet in latitude-longitude locations.  It has not been thoroughly tested, so not all options may work properly - but this was the intention.


Terrain modeling and Soil Erosion Simulations for Fort Hood and Fort Polk test areas, by Helena Mitasova, Lubos Mitas, William M. Brown, Douglas M.  Johnston, GMSL (Report for CERL 1999)

See Also

r.flow, r.fill.dir, r.watershed


Bill Brown (GMSL)
GRASS 6 update: Brad Douglas

Last changed: $Date: 2015-05-11 02:11:34 +0200 (Mon, 11 May 2015) $

Source Code

Available at: r.carve source code (history)

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