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r.carve(1)		    GRASS GIS User's Manual		    r.carve(1)

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=nameA [required]
	   Name	of input raster	elevation map

       vector=nameA [required]
	   Name	of input vector	map containing stream(s)
	   Or data source for direct OGR access

       output=nameA [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:
       # set computational region
       g.region	raster=elev_lid792_1m -p
       # visualize original data
       d.mon wx0
       d.rast elev_lid792_1m
       d.vect streams
       # carve
       r.carve rast=elev_lid792_1m vect=streams	out=carved_dem width=3 depth=0.5
       # visualize resulting carved DEM	map
       d.rast carved_dem
       # visualize
       r.relief	input=elev_lid792_1m output=elev_lid792_1m_shaded
       r.relief	input=carved_dem output=carved_dem_shaded
       d.rast elev_lid792_1m_shaded
       d.erase
       d.rast carved_dem_shaded
       # flow accumulation
       r.watershed elevation=elev_lid792_1m accumulation=elev_lid792_1m_accum
       r.watershed elevation=carved_dem	accumulation=carved_dem_accum
       d.rast elev_lid792_1m_accum
       d.erase
       d.rast carved_dem_accum

       Fig:  Original 1m LiDAR based DEM with vector streams map on Fig: Original 1m LiDAR based DEM shown as shaded terrain
       top

       Fig: Carved 1m LiDAR based DEM				    Fig: Carved	1m LiDAR based DEM shown as shaded terrain

       Fig: Flow accumulation in original 1m LiDAR based DEM	    Fig: Flow accumulation in carved 1m	LiDAR based DEM

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

SOURCE CODE
       Available at: r.carve source code (history)

       Main index | Raster index | Topics index	| Keywords index  |  Graphical
       index | Full index

       A(C) 2003-2020 GRASS Development	Team, GRASS GIS	7.8.3 Reference	Manual

GRASS 7.8.3							    r.carve(1)

NAME | KEYWORDS | SYNOPSIS | DESCRIPTION | NOTES | EXAMPLE | KNOWN ISSUES | REFERENCES | SEE ALSO | AUTHOR | SOURCE CODE

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