[GRASS-user] r.watershed

GRASS GRASS user
1

Hi,

I got an similar error message like Wes Kent (Janurary 2008).

http://img361.imageshack.us/my.php?image=rwatershedvl0.jpg

I use the SRTM-Data (90m) and merge with r.patch 6 tiles. So I have ca 180.000.000 cells.
Without the -m flag the process crashed immediatly. So I set this and get the error message above.

The threshold-value I set to 400000.
My laptop has an 2,5GHz processor and 4 GB Ram. When I start the process the CPU is nearly 50% and the memory usage is never higher than 50Mbyte. With the -m flag only 2 MB. Is this normal. Why grass doesn't use more memory for calculating.
This is under windows. I installed a virtual machine with ubuntu and get the same result.

What can I do to process the data. Is the raster to big?
the same with r.fill.dir or how long time takes the calculation for this.

best regards
Alex
__________________________________________________________________________
Verschicken Sie SMS direkt vom Postfach aus - in alle deutschen und viele
ausländische Netze zum gleichen Preis!
https://produkte.web.de/webde_sms/sms

2

Hi.

is there nobody who has experience with r.watershed. And could me say if something is wrong or wathever.
Now the process runs more than 2 days and nothing

r.watershed -m elevation=dem.senkenloseHoehenkarte4 threshold=400000 accumulation=dem.Akkumulation400000

         drainage=dem.Fliessrichtung_Drainage400000 basin=Wassereinzugsgebiete400000
         stream=dem.Fliesswassersegmente400000

SECTION 1 beginning: Initiating Variables. 5 sections total.
SECTION 1b (of 5): Determining Offmap Flow.
WARNING: segment_pagein: read EOF
WARNING: seg_put(): could not write segment file

After 20 minutes these warnings appear and then ....

Does somebody know what these warnings means?

Crashes the process or should I wait?

thanks in advance
Alex

Alex Schulze schrieb:

Hi,

I got an similar error message like Wes Kent (Janurary 2008).

http://img361.imageshack.us/my.php?image=rwatershedvl0.jpg

I use the SRTM-Data (90m) and merge with r.patch 6 tiles. So I have ca 180.000.000 cells.
Without the -m flag the process crashed immediatly. So I set this and get the error message above.

The threshold-value I set to 400000.
My laptop has an 2,5GHz processor and 4 GB Ram. When I start the process the CPU is nearly 50% and the memory usage is never higher than 50Mbyte. With the -m flag only 2 MB. Is this normal. Why grass doesn't use more memory for calculating.
This is under windows. I installed a virtual machine with ubuntu and get the same result.

What can I do to process the data. Is the raster to big?
the same with r.fill.dir or how long time takes the calculation for this.

best regards
Alex
__________________________________________________________________________
Verschicken Sie SMS direkt vom Postfach aus - in alle deutschen und viele ausländische Netze zum gleichen Preis! https://produkte.web.de/webde_sms/sms

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3

On Sun, Sep 14, 2008 at 6:10 PM, Alexander Schulze <schulzibabe@web.de> wrote:

Hi.

is there nobody who has experience with r.watershed. And could me say if
something is wrong or wathever.
Now the process runs more than 2 days and nothing

r.watershed -m elevation=dem.senkenloseHoehenkarte4 threshold=400000
          accumulation=dem.Akkumulation400000
              drainage=dem.Fliessrichtung_Drainage400000
            basin=Wassereinzugsgebiete400000
              stream=dem.Fliesswassersegmente400000

SECTION 1 beginning: Initiating Variables. 5 sections total.
SECTION 1b (of 5): Determining Offmap Flow.
WARNING: segment_pagein: read EOF

This happens in
lib/segment/pagein.c

function segment_pagein()

WARNING: seg_put(): could not write segment file

Could the disk be temporarily full?

Markus

After 20 minutes these warnings appear and then ....

Does somebody know what these warnings means?

Crashes the process or should I wait?

thanks in advance
Alex