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<div class="moz-cite-prefix">On 02/13/2015 08:48 PM, Thomas Adams
wrote:<br>
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cite="mid:CAGxgkWigYkhqvN0gFV5LW8QCn=SxoBxdrfwEcQazwhtAXjDe6Q@mail.gmail.com"
type="cite">
<div dir="ltr">Stefan,
<div><br>
</div>
<div>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.</div>
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Are these breaks possibly caused by null pixels in the DEM? <br>
<br>
<blockquote
cite="mid:CAGxgkWigYkhqvN0gFV5LW8QCn=SxoBxdrfwEcQazwhtAXjDe6Q@mail.gmail.com"
type="cite">
<div dir="ltr">
<div>Tom</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Fri, Feb 13, 2015 at 11:43 AM,
Stefan Lüdtke <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:sluedtke@gfz-potsdam.de" target="_blank">sluedtke@gfz-potsdam.de</a>></span>
wrote:<br>
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Hi Tom,<br>
<br>
just out of curiosity, what do you mean by "break in the
flow<br>
accumulation"?<br>
<br>
Cheers,<br>
<br>
Stefan<br>
<div>
<div class="h5"><br>
On 02/13/2015 07:12 PM, Thomas Adams wrote:<br>
> Hello all!<br>
><br>
> I'm making use of the flow accumulation grid in
GRASS 6.4.5<br>
> generated from r.watershed using the SFD (D8)
flow algorithm. The<br>
> DEM has a 250m spatial resolution. What I'm
getting is a break in<br>
> the flow accumulation in a few locations which is
causing me<br>
> serious problems with subsequent processing (with
help from some<br>
> here, I have put together some scripting to
generate a pixel<br>
> connectivity file for a distributed hydrologic
model).<br>
><br>
> Besides going to a higher resolution DEM, are
there any thoughts as<br>
> to how I can eliminate these flow accumulation
breaks?<br>
><br>
> Thank you, Tom<br>
><br>
> --<br>
><br>
><br>
><br>
</div>
</div>
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<br>
- --<br>
Stefan Lüdtke<br>
<br>
Section 5.4- Hydrology<br>
Tel.: <a moz-do-not-send="true"
href="tel:%2B49%20331%20288%202821"
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<br>
Helmholtz-Zentrum Potsdam<br>
Deutsches GeoForschungsZentrum GFZ<br>
(GFZ German Research Centre for Geoscience)<br>
Stiftung des öff. Rechts Land Brandenburg<br>
Telegrafenberg, 14473 Potsdam<br>
- -------------------<br>
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PGP Public Key: <a moz-do-not-send="true"
href="http://bit.ly/13d9Sca" target="_blank">http://bit.ly/13d9Sca</a><br>
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-- <br>
<div class="gmail_signature"><br>
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