[GRASS-user] r.hazard.flood: ERROR_G_malloc: r_accumulation

[Markus Metz]

On Tue, Jun 11, 2013 at 6:36 AM, RichardC <richtcooper at hotmail.com> wrote:
> Thanks for your suggestions.
>
> I modified the following:
>
> /home/user/.grass6/addons/scripts/r.hazard.flood, replacing:
>
> # Flow accumulation map MFD
>     grass.run_command('r.watershed', elevation = r_elevation , accumulation
> = 'r_accumulation' , convergence = 5, flags = 'fa')
>     grass.message("Flow accumulation done. ")
>
> with
>
>   # Flow accumulation map MFD
>     grass.run_command('r.watershed', elevation = r_elevation , accumulation
> = 'r_accumulation' , convergence = 5, flags = 'am')

For GRASS 6, you should keep the -f flag for MFD.

>     grass.message("Flow accumulation done. ")
>
> This enabled me run r.hazard.flow on a portion (sub-basin) of the DEM. I ran
> into trouble if I attempted the larger mosaic I created, as follows:
>
> r.hazard.flood.py map=ASTGTM_composite_all at PERMANENT
> flood=ASTGTM_composite_all_flood mti=ASTGTM_composite_all_mti
> Cellsize : 30.0
> SECTION 1 beginning: Initiating Variables. 4 sections total.
> WARNING: segment zero_fill(): Unable to write (No such file or directory)

This warning indicates that either you were running out of disk space
or the temporary file would be larger than supported (GRASS 6 has no
global Large File Support), or both.

> WARNING: seg_open(): could not write segment file
> SECTION 1b (of 4): Determining Offmap Flow.
> Floating point exception (core dumped)
> WARNING: Subprocess failed with exit code 34816
> WARNING: category information for [r_accumulation] in [PERMANENT] missing or
> invalid
> Flow accumulation done.
> Slope raster map <r_slope> complete
> Slope map done.
> Exponent : 0.076488432313
> MTI threshold : 3.11495902789
> Calculating mti raster map..
> Invalid map <r_accumulation>
> Parse error
> ERROR: An error occurred while running r.mapcalc
> (Tue Jun 11 10:55:33 2013) Command finished (9 min 3 sec)
>
> I guess the workaround solution is to reduce the spatial extent and run each
> sub-basin separately with r.hazard.flood (if possible for all I'm not sure)
>
> Install GRASS 7 - installing from source into my home directory I think
> should allow two systems to work on my machine ...

That would work, I have 4 different GRASS versions running on my
machine. Note that you do not need to run 'make install' in order to
use GRASS.
>
>
> My current system:
>
> uname -a: Linux 3.2.0-31-generic-pae #50-Ubuntu SMP Fri Sep 7 16:39:45 UTC
> 2012 i686 i686 i386 GNU/Linux

You are using a 32 bit system (why?), therefore you need to configure
GRASS with --enable-largefile.

HTH,

Markus M

>
> I'm running Linux Mint 13 (Maya) which is based on Ubuntu Precise (installed
> system wide via package manager)
>
> GRASS version: 6.4.3 (Python 2.7.3/wxpython 2.8.12.1)
> GRASS: 6.4.3-1~svn54876~precise1
>
> NB: I just noticed that the repo has been updated with 6.4.3 (RC3-4) ...
>
>
>
>
>
> --
> View this message in context: http://osgeo-org.1560.x6.nabble.com/r-hazard-flood-ERROR-G-malloc-r-accumulation-tp5059130p5059281.html
> Sent from the Grass - Users mailing list archive at Nabble.com.
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