This is the command r.carvegrass that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator
PROGRAM:
NAME
r.carve - Generates stream channels.
Takes vector stream data, transforms it to raster and subtracts depth from the output DEM.
KEYWORDS
raster, hydrology
SYNOPSIS
r.carve
r.carve --help
r.carve [-n] raster=name vector=name output=name [points=name] [width=float]
[depth=float] [--overwrite] [--help] [--verbose] [--quiet] [--ui]
Flags:
-n
No flat areas allowed in flow direction
--overwrite
Allow output files to overwrite existing files
--help
Print usage summary
--verbose
Verbose module output
--quiet
Quiet module output
--ui
Force launching GUI dialog
Parameters:
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
points=name
Name for output vector map for adjusted stream points
width=float
Stream width (in meters)
Default is raster cell width
depth=float
Additional stream depth (in meters)
DESCRIPTION
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.
NOTES
r.carve does not create a depressionless DEM because many depressions are in flat areas
and not in the streams.
EXAMPLE
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.
REFERENCES
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)
Use r.carvegrass online using onworks.net services
