1r.volume(1) Grass User's Manual r.volume(1)
2
6 r.volume - Calculates the volume of data "clumps".
7 Optionally produces a GRASS vector points map containing the calculated
8 centroids of these clumps.
9
11 raster, volume, clumps
12
14 r.volume
15 r.volume --help
16 r.volume [-f] input=name [clump=name] [centroids=name] [out‐
17 put=name] [--overwrite] [--help] [--verbose] [--quiet] [--ui]
18 Flags:
20 -f
21 Generate unformatted report (items separated by colon)
22 --overwrite
24 Allow output files to overwrite existing files
25 --help
27 Print usage summary
28 --verbose
30 Verbose module output
31 --quiet
33 Quiet module output
34 --ui
36 Force launching GUI dialog
37 Parameters:
39 input=name [required]
40 Name of input raster map representing data that will be summed
41 within clumps
42 clump=name
44 Name of input clump raster map
45 Preferably the output of r.clump. If no clump map is given than
46 MASK is used.
47 centroids=name
49 Name for output vector points map to contain clump centroids
50 output=name
52 Name for output file to hold the report
53 If no output file given report is printed to standard output
54
56 r.volume is a tool for summing cell values within clumps and calculat‐
57 ing volumes and centroids of patches or clumps.
58 r.volume generates a table containing the sum of all cells from a input
60 raster map sorted by category on a clump raster map, and optionally
61 generates a vector points map of the centroids for each clump. If a
62 clump map is not specified, the current MASK is used. The MASK can be
63 defined by r.mask. The sum is multiplied by the area of a cell to give
64 the volume occupied by that cell. See below for an example of the out‐
65 put table.
66
68 If a clump map is not given and a MASK not set, the program exits with
69 an error message.
70 r.volume works in the current region and respects the current MASK.
72 CENTROIDS
74 The centroid coordinates are the same as those stored in the vector map
75 (if one was requested by centroids parameter). They are guaranteed to
76 fall on a cell of the appropriate category, thus they are not always
77 the true, mathematical centroid. They will always fall at a cell cen‐
78 ter.
79 Attribute table linked to the vector map with centroids contains sev‐
81 eral columns:
82 · cat - category value (integer)
84 · volume - volume value (double precision)
86 · average - average value in the clump (double precision)
88 · sum - sum of cell values in the clump (double precision)
90 · count - number of cells with the category (integer)
92 Vector points can be converted directly to a raster map with each point
94 a separate category using v.to.rast.
95 APPLICATIONS
97 By preprocessing the elevation raster map with r.mapcalc and using
98 suitable masking or clump maps, very interesting applications can be
99 done with r.volume. Such as, calculating the volume of rock in a
100 potential quarry; calculating cut/fill volumes for roads; finding water
101 volumes in potential reservoirs.
102
104 The following report was generated by the command (North Carolina
105 dataset):
106 # set computational region
107 g.region raster=elevation
108 # compute volume
109 r.volume input=elevation clump=geology_30m
110 Volume report on data from <elevation> using clumps on <geology_30m> raster map
111 Category Average Data # Cells Centroid Total
112 Number in clump Total in clump Easting Northing Volume
113 -----------------------------------------------------------------------------
114 217 118.93 86288828 725562 635325.00 221535.00 8628882798.63
115 262 108.97 21650560 198684 638935.00 222495.00 2165056037.02
116 270 92.23 63578874 689373 642405.00 221485.00 6357887443.53
117 405 132.96 33732662 253710 631835.00 224095.00 3373266208.59
118 583 139.35 3011288 21609 630205.00 224665.00 301128821.55
119 720 124.30 599618 4824 634075.00 227995.00 59961816.06
120 766 132.43 936791 7074 631425.00 227845.00 93679120.08
121 862 118.31 7302317 61722 630505.00 218885.00 730231746.74
122 910 94.20 4235816 44964 639215.00 216365.00 423581613.11
123 921 135.22 1693985 12528 630755.00 215445.00 169398523.05
124 945 127.24 1145 9 630015.00 215015.00 114512.03
125 946 89.91 365748 4068 639085.00 215255.00 36574833.85
126 948 129.02 112632 873 630185.00 215115.00 11263181.57
127 -----------------------------------------------------------------------------
128 Total Volume = 22351026655.81
129 The Data Total column is the sum of the elevations for each in each of
130 the fields. The Total Volume is the sum multiplied by the east-west
131 resolution times the north-south resolution. Note that the units on the
132 volume may be difficult if the units of cell values on the input raster
133 map and the resolution units differ.
134
136 r.clump, r.mask, r.mapcalc
137
139 Dr. James Hinthorne, Central Washington University GIS Laboratory,
140 December 1988.
141 Updated to GRASS 7 by Martin Landa, Czech Technical University in
142 Prague, Czech Republic
143 Last changed: $Date: 2014-12-19 22:17:36 +0100 (Fri, 19 Dec 2014) $
145
147 Available at: r.volume source code (history)
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151 © 2003-2019 GRASS Development Team, GRASS GIS 7.6.0 Reference Manual
153GRASS 7.6.0 r.volume(1)