[GRASS-user] Question about r.watershed and flow accumulation grid

[Thomas Adams]

Stefan,

A fair question; since I know the stream topology from personal experience
it is clear that there should be no break in the stream network and the
flow accumulation grid should reflect that. I am seeing the flow
accumulation values break at a point where they should continue to
accumulate downstream.

Tom

On Fri, Feb 13, 2015 at 11:43 AM, Stefan Lüdtke <sluedtke at gfz-potsdam.de>
wrote:

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> Hi Tom,
>
> just out of curiosity, what do you mean by "break in the flow
> accumulation"?
>
> Cheers,
>
> Stefan
>
> On 02/13/2015 07:12 PM, Thomas Adams wrote:
> > Hello all!
> >
> > I'm making use of the flow accumulation grid in GRASS 6.4.5
> > generated from r.watershed using the SFD (D8) flow algorithm. The
> > DEM has a 250m spatial resolution. What I'm getting is a break in
> > the flow accumulation in a few locations which is causing me
> > serious problems with subsequent processing (with help from some
> > here, I have put together some scripting to generate a pixel
> > connectivity file for a distributed hydrologic model).
> >
> > Besides going to a higher resolution DEM, are there any thoughts as
> > to how I can eliminate these flow accumulation breaks?
> >
> > Thank you, Tom
> >
> > --
> >
> >
> >
> > _______________________________________________ grass-user mailing
> > list grass-user at lists.osgeo.org
> > http://lists.osgeo.org/mailman/listinfo/grass-user
> >
>
> - --
> Stefan Lüdtke
>
> Section 5.4-  Hydrology
> Tel.: +49 331 288 2821
> Fax: +49 331 288 1570
> Email: sluedtke at gfz-potsdam.de
>
> Helmholtz-Zentrum Potsdam
> Deutsches GeoForschungsZentrum GFZ
> (GFZ German Research Centre for Geoscience)
> Stiftung des öff. Rechts Land Brandenburg
> Telegrafenberg, 14473 Potsdam
> - -------------------
>
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