1r.carve(1) GRASS GIS User's Manual r.carve(1)
2
6 r.carve - Generates stream channels.
7 Takes vector stream data, transforms it to raster and subtracts depth
8 from the output DEM.
9
11 raster, hydrology
12
14 r.carve
15 r.carve --help
16 r.carve [-n] raster=name vector=name output=name [points=name]
17 [width=float] [depth=float] [--overwrite] [--help] [--verbose]
18 [--quiet] [--ui]
19 Flags:
21 -n
22 No flat areas allowed in flow direction
23 --overwrite
25 Allow output files to overwrite existing files
26 --help
28 Print usage summary
29 --verbose
31 Verbose module output
32 --quiet
34 Quiet module output
35 --ui
37 Force launching GUI dialog
38 Parameters:
40 raster=name [required]
41 Name of input raster elevation map
42 vector=name [required]
44 Name of input vector map containing stream(s)
45 Or data source for direct OGR access
46 output=name [required]
48 Name for output raster map
49 points=name
51 Name for output vector map for adjusted stream points
52 width=float
54 Stream width (in meters)
55 Default is raster cell width
56 depth=float
58 Additional stream depth (in meters)
59
61 r.carve accepts vector stream data as input, transforms them to raster,
62 and subtracts a default-depth + additional-depth from a DEM. If the
63 given width is more than 1 cell, it will carve the stream with the
64 given width. With the -n flag it should eliminate all flat cells within
65 the stream, so when and if the water gets into the stream it will flow.
66 The points option generates x,y,z for points which define the stream
67 with the z-value of the bottom of the carved-in stream. These points
68 can then be combined with contours to interpolate a new DEM with better
69 representation of valleys.
70
72 r.carve does not create a depressionless DEM because many depressions
73 are in flat areas and not in the streams.
74
76 North Carolina sample dataset:
77 # set computational region
78 g.region raster=elev_lid792_1m -p
79 # digitize a ditch for the farm pond
80 echo "L 3 1
81 638692.93595422 220198.90026383
82 638737.42270627 220149.74706926
83 638984.43306379 220148.19158842
84 1 1" | v.in.ascii -n input=- output=ditch format=standard
85 # visualize original data
86 d.mon wx0
87 d.rast elev_lid792_1m
88 d.vect ditch
89 # carve
90 r.carve raster=elev_lid792_1m vector=ditch output=carved_dem width=3 depth=0.5
91 # visualize resulting carved DEM map
92 d.rast carved_dem
93 # visualize
94 r.relief input=elev_lid792_1m output=elev_lid792_1m_shaded
95 r.relief input=carved_dem output=carved_dem_shaded
96 d.rast elev_lid792_1m_shaded
97 d.erase
98 d.rast carved_dem_shaded
99 # flow accumulation
100 r.watershed elevation=elev_lid792_1m accumulation=elev_lid792_1m_accum
101 r.watershed elevation=carved_dem accumulation=carved_dem_accum
102 d.rast elev_lid792_1m_accum
103 d.erase
104 d.rast carved_dem_accum
105 # differences
106 r.mapcalc "accum_diff = elev_lid792_1m_accum - carved_dem_accum"
107 r.colors accum_diff color=differences
108 d.erase
109 d.rast accum_diff
110 Fig: Original 1m LiDAR based DEM with vector streams map on Fig: Original 1m LiDAR based DEM shown as shaded terrain
112 top
113 Fig: Carved 1m LiDAR based DEM Fig: Carved 1m LiDAR based DEM shown as shaded terrain
115 Fig: Flow accumulation in original 1m LiDAR based DEM Fig: Flow accumulation in carved 1m LiDAR based DEM
117
120 The module does not operate yet in latitude-longitude locations. It
121 has not been thoroughly tested, so not all options may work properly -
122 but this was the intention.
123
125 Terrain modeling and Soil Erosion Simulations for Fort Hood and Fort
126 Polk test areas, by Helena Mitasova, Lubos Mitas, William M. Brown,
127 Douglas M. Johnston, GMSL (Report for CERL 1999)
128
130 r.flow, r.fill.dir, r.watershed
131
133 Bill Brown (GMSL)
134 GRASS 6 update: Brad Douglas
135
137 Available at: r.carve source code (history)
138 Main index | Raster index | Topics index | Keywords index | Graphical
140 index | Full index
141 © 2003-2020 GRASS Development Team, GRASS GIS 7.8.5 Reference Manual
143GRASS 7.8.5 r.carve(1)