On Sat, Mar 30, 2019 at 5:30 PM Micha Silver <[email protected]> wrote: > > > On 29/03/2019 22:03, Adrien André wrote: > > Hello, > > following the wiki doc about stream extraction [1], once the stream layer thinned and vectorized, > there are many small arcs i would like to remove (see attached capture [2]). > > So, with the underlying drainage direction map [3], and the resolution r, i would like to delete segments > - about r*sqrt(2) long > - whose azimuth is more than 45° different from the pixel value under its starting point. > > > This might be possible, but I think the best approach would be to choose the correct threshold value for r.watershed from the start. > > Trying to manually "fiddle" with the stream network will most likely leave you with disconnected segments, or other inconsistencies.
+1 Please try r.stream.extract in order to get a clean vector stream network. The approach r.thin + r.to.vect creates noise and does not always follow flow directions. Markus M > > > But i still haven't figured a way to achieve this. > > Do you have any advice ? > > Thank you, > > Best regards, > > [1] https://grasswiki.osgeo.org/wiki/Creating_watersheds#Display_first_results > [2] https://framapic.org/1exdxrdqxemw/ytuVxiBp2FKh.png > [3] https://grass.osgeo.org/grass74/manuals/r.watershed.html > > > _______________________________________________ > grass-user mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/grass-user > > -- > Micha Silver > Ben Gurion Univ. > Sde Boker, Remote Sensing Lab > cell: +972-523-665918 > > _______________________________________________ > grass-user mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/grass-user
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