[GRASS-user] grass-user Digest, Vol 106, Issue 34

[Thomas Adams]

Thayer,

Thank you for the suggestion; I just tried it with the same result. I think
the area just happens to be a difficult area, that is pretty flat…

Cheers!
Tom

On Fri, Feb 13, 2015 at 1:54 PM, Thayer Young <thayeray at yahoo.com> wrote:

> I don't know if you have tried this yet, but you may also want to look at
> r.terraflow.  It does both D8 (single flow direction) and multiple flow
> direction (flow is partitioned, according to the steepness of slope, to all
> directions that are lower than the central cell).  Supposedly you can also
> switch from MFD to SFD once flow exceeds a threshold, but I have not been
> successful at doing this.  It would be a simple simulation of
> channelization though.
>
> Just set the D8 flag in the options tab, otherwise it will give you MFD by
> default.
>
> -Thayer
>
>
>   ------------------------------
> Date: Fri, 13 Feb 2015 11:12:30 -0700
> From: Thomas Adams <tea3rd at gmail.com>
> To: "grass-user at lists.osgeo.org" <grass-user at lists.osgeo.org>
> Subject: [GRASS-user] Question about r.watershed and flow accumulation
>     grid
> Message-ID:
>     <CAGxgkWgefeTtcjZWKi3JP8wj79Eb0j3fZsf6hGzT8m9-dgce6w at mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> 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
>
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-- 
Thomas E Adams, III
718 McBurney Drive
Lebanon, OH 45036

1 (513) 739-9512 (cell)
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