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)

SEE ALSO

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

AUTHOR

       Bill Brown (GMSL)
       GRASS 6 update: Brad Douglas

       Last changed: $Date: 2015-05-11 02:16:13 +0200 (Mon, 11 May 2015) $

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