[GRASS-user] calculate the volume of a DEM with r.volume

GRASS GRASS user
1

Hello,

I tried using r.volume as you suggested. According to the documentation it is suitable for what I am trying to do.

However, when I use it, I don’t have the “Total volume” line at the end of the report, like it is shown in the documentation. I just have the total volume of each clump, but not of all the clumps… Has it ever happened to you when using this command? in the command line

I simply wroter.volume input=difference clump=clump in the command line

Thank you very much,
Marion
De : “Markus Neteler”
A : marion-brunet@sfr.fr,“grass-user”
Envoyé: mardi 10 juillet 2018 13:39
Objet : Re: [GRASS-user] calculate the volume of a DEM

Hi,

On Tue, Jul 10, 2018 at 6:04 AM, wrote:
…

I had two DEMS and I used r.mapcalc to get
the difference between them. I want to calculate the total volume of this
last raster.

I wonder if
https://grass.osgeo.org/grass74/manuals/r.volume.html
could be of any use here?

Markus

2

Hello Marion,

On Wed, Jul 11, 2018 at 10:32 AM, <marion-brunet@sfr.fr> wrote:

Hello,

I tried using r.volume as you suggested. According to the documentation it
is suitable for what I am trying to do.

However, when I use it, I don’t have the “Total volume” line at the end of
the report, like it is shown in the documentation. I just have the total
volume of each clump, but not of all the clumps… Has it ever happened to
you when using this command?

That’s weird! Which version/operating system do you use?

in the command line

I simply wroter.volume input=difference clump=clump in the command line

Here on command line:

GRASS 7.4.1svn (nc_spm_08_grass7):~ > g.region raster=elevation
GRASS 7.4.1svn (nc_spm_08_grass7):~ > r.volume input=elevation clump=geology_30m
100%

Volume report on data from using clumps on <geology_30m> raster map

Category Average Data # Cells Centroid Total
Number in clump Total in clump Easting Northing Volume

217 118.93 86288828 725562 635325.00 221535.00 8628882798.63
262 108.97 21650560 198684 638935.00 222495.00 2165056037.02
270 92.23 63578874 689373 642405.00 221485.00 6357887443.53
405 132.96 33732662 253710 631835.00 224095.00 3373266208.59
583 139.35 3011288 21609 630205.00 224665.00 301128821.55
720 124.30 599618 4824 634075.00 227995.00 59961816.06
766 132.43 936791 7074 631425.00 227845.00 93679120.08
862 118.31 7302317 61722 630505.00 218885.00 730231746.74
910 94.20 4235816 44964 639215.00 216365.00 423581613.11
921 135.22 1693985 12528 630755.00 215445.00 169398523.05
945 127.24 1145 9 630015.00 215015.00 114512.03
946 89.91 365748 4068 639085.00 215255.00 36574833.85
948 129.02 112632 873 630185.00 215115.00 11263181.57

Total Volume = 22351026655.81

… which looks ok.

Can you say a bit more about your system?

Markus