[GRASS-user] SRTM r.watershed at multiple scales
sluedtke at gfz-potsdam.de
Thu Feb 20 11:25:47 PST 2014
I experienced a similar point, but, if I remember right, this was
because I set the computational region to the extend of the catchment
produced by r.water.outlet. So maybe the MASK has a similar effect and
r.watershed needs kind of buffer. Should be easy to check ...
On 02/20/2014 07:11 PM, Michel Wortmann wrote:
> Here is what I think is strange though about your explanation, Markus:
> If I first mask a watershed produced with r.water.outlet and then use
> r.watershed to produce subbasins, it doesnt include the entire area of
> the watershed but leaves small areas out, although these areas belong to
> it. Is this a threshold problem?
> Tom, see image attached.
> On 02/19/2014 04:42 PM, Thomas Adams wrote:
>> I've been using GRASS 7 for this and have not seen a problem -- I hope
>> I'm not overlooking the issue. Michel, can you provide an image that
>> shows this?
>> On Wednesday, February 19, 2014, Michel Wortmann
>> <wortmann at pik-potsdam.de <mailto:wortmann at pik-potsdam.de>> wrote:
>> last year you asked me whether the r.watershed output is not
>> aligned to the r.water.outlet output in GRASS7 (s.b.). Ie. it
>> leaves small areas out. Back then, I wasnt using GRASS7, but I can
>> confirm now that it still does it and it is still rather annoying.
>> Have you ever heard of the reasons or attempted to fix this?
>> On 08/26/2013 03:25 PM, Markus Neteler wrote:
>> On 08/22/2013 08:52 AM, Markus Neteler wrote:
>> >>Hi Michel,
>> >>On Wed, Aug 21, 2013 at 1:18 PM, Michel Wortmann
>> >><wortmann at pik-potsdam.de> wrote:
>> >>>As the r.watershed algorithm often leaves small
>> areas at the edges
>> >>>uncovered, you'll have to fill those before or
>> after patching, otherwise
>> >>>you'll have holes in your subbasin map.
>> >>... just curious: does this happen still in the latest
>> GRASS 7 version?
>> grass-user mailing list
>> grass-user at lists.osgeo.org
>> Thomas E Adams, III
>> 718 McBurney Drive
>> Lebanon, OH 45036
>> 1 (513) 739-9512 (cell)
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