[GRASS-user] limit number of confluent streams in r.steam.extract or r.watershed

[Markus Metz]

On Wed, Jul 11, 2018 at 3:55 AM, Huidae Cho <grass4u at gmail.com> wrote:
>
> Hello,
>
> Not sure if I understood your question. Are you trying to extract major
streams only? r.stream.extract already returns a valid stream network with
confluences snapped to the main stem. Also, limiting the number of
confluent streams and moving (?) streams at the confluences are two
different tasks, I believe. Maybe, you need to be more specific with some
examples.

Limiting the number of confluent streams would conflict with both the
method to determine flow directions and the method to extract streams.
Moving streams at confluences a tiny little bit is IMHO a custom
post-processing step.

I would rather suggest to enhance the R package SSN such that it can deal
with more than two streams joining at a confluence. But maybe SSN is meant
to work with major streams only, in which case the threshold to extract
streams would need to be increased.

Markus M

>
> Regards,
> Huidae
>
>
> On Thu, Jul 5, 2018 at 6:40 AM, Mira Kattwinkel <
kattwinkel-mira at uni-landau.de> wrote:
>>
>> Dear list,
>>
>> is there any way to limit the number of confluent streams in
r.stream.extract or r.watershed?
>>
>> I am working with statistical models (R package SSN) that can only deal
with such dichotomous networks. Currently, I am developing a method to move
streams a tiny bit at the confluences to get a valid network, but I wonder
if something like this already exists. That would make my life much easier.
>>
>> All the best,
>>
>> Mira
>>
>> ---
>>
>> Dr. Mira Kattwinkel
>> Quantitative Landscape Ecology
>> Institute for Environmental Sciences
>> University of Koblenz-Landau
>> Fortstraße 7
>> 76829 Landau
>> Germany
>> Phone: + 49 6341 280-31553
>> Office: Building I, Room 2.02
>>
>> _______________________________________________
>> grass-user mailing list
>> grass-user at lists.osgeo.org
>> https://lists.osgeo.org/mailman/listinfo/grass-user
>
>
>
>
> --
> Huidae Cho, Ph.D., PE, M.ASCE, CFM, GISP
> Senior Geospatial Engineer, MapAnything
> Open Source GIS Developer, GRASS GIS Development Team
>
> _______________________________________________
> grass-user mailing list
> grass-user at lists.osgeo.org
> https://lists.osgeo.org/mailman/listinfo/grass-user
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/grass-user/attachments/20180711/c0033b15/attachment.html>