[GRASS-user] patching vectors - some are not patched

[Ken Mankoff]

On 2018-11-19 at 16:59 +0100, Markus Metz <markus.metz.giswork at gmail.com> wrote:

> looking at your aim: get basins for all outlets, you could also use
> 1. r.stream.extract with stream_vector as output
> outlets have category value 2 in layer 2
> 2. extract the outlets with v.extract lyer=2 type=point cats=2
> 3. use the outlets as input for r.stream.basins

Yes this is my main aim, but as usual things are getting more complicated.

It turns out I cannot use r.watershed over sub-regions (even if I overlap and then crop) because it produced bad output due to catchments meeting the edge of regions. So I'm going back to r.terraflow.

r.terraflow means I don't have access to the stream maps that you're suggesting I use. I also have "direction" in a different format than all the other tools want, but I can convert it. I'm not sure what to do about the interior basins that r.terraflow leaves unlike r.watershed which fills them... I think I'll run all my 'r.water.outlets', generate my raster basins, then flood each basin so that the interior basins are now included.

All this is complicated by the fact that I'm working with a 4.5 billion cell raster (90,000 x 50,000) with ~100,000 outlets (catchments). I have it running fairly fast on my laptop thanks to GNU parallel and WIND_OVERRIDE.

Work is in progress...

  -k.