[GRASS-user] Filling sinks w/ minimum slope

[Ken Mankoff]

On 2017-06-20 at 06:28, Markus Metz <markus.metz.giswork at gmail.com> wrote:
> You don't need to fill sinks with r.watershed, internal sinks are by
> default drained.

I have negative values in the drainage direction raster produced by r.watershed in the interior. Is this a bug? Or am I misunderstanding the definition of a sink?

While looking into this, I also notice that I get different accumulation maps if I scale the elevation (e.g. divide by 100), even when using the "-s" flag. At first consideration, this does not make sense to me.

> You can create flat areas (also with r.terraflow), then use the -b
> flag of r.watershed to create a gentle slope for flat areas.

I tried this and the accumulation map still has end-points (and direction has negative values) in the interior.

  -k.