Re: [GRASS-user] r.water.outlet map does not display

2017-03-06 Thread Rich Shepard

On Tue, 7 Mar 2017, Sören Gebbert wrote:


Yes. The watershed computed via r.water.outlet may be only a single pixel
in size, if your outlet point is not located on a stream. Better use
r.watershed.


Sören,

  I ran r.watershed first. But, since there are no streams present no map
was produced.

  Because I could not create the mask using r.watershed and r.water.outlet I
manually digitized (in the map display window) a smaller area, converted
that to a raster map, then used that for the mask. Itzi is now happy and
running much faster than before.

Thanks,

Rich
___
grass-user mailing list
grass-user@lists.osgeo.org
https://lists.osgeo.org/mailman/listinfo/grass-user

Re: [GRASS-user] r.water.outlet map does not display

2017-03-06 Thread Sören Gebbert
Am 06.03.2017 11:50 PM schrieb "Rich Shepard" :

  Using r.watershed specifying the input DEM and a name for the drainage map
I can view the drainage map. When I follow this command with r.water.outlet
specifying the drainage map as input, 'watershed' as the output map name,
and the coordinates of the designated outlet, no map is displayable.

  Could this be due to the very flat nature of the terrain?


Yes. The watershed computed via r.water.outlet may be only a single pixel
in size, if your outlet point is not located on a stream. Better use
r.watershed.


Rich
___
grass-user mailing list
grass-user@lists.osgeo.org
https://lists.osgeo.org/mailman/listinfo/grass-user
___
grass-user mailing list
grass-user@lists.osgeo.org
https://lists.osgeo.org/mailman/listinfo/grass-user

Re: [GRASS-user] r.water.outlet map does not display

2017-03-06 Thread Laurent C.
Hello,

You should make sure that the point you give to r.water.outlet is
located on a main stream. The accumulation map from r.watershed is
useful for this task.
If you're not doing so, you might end up with a tiny watershed.

Regards,
Laurent


2017-03-06 16:50 GMT-06:00 Rich Shepard :
>   Using r.watershed specifying the input DEM and a name for the drainage map
> I can view the drainage map. When I follow this command with r.water.outlet
> specifying the drainage map as input, 'watershed' as the output map name,
> and the coordinates of the designated outlet, no map is displayable.
>
>   Could this be due to the very flat nature of the terrain?
>
> Rich
> ___
> grass-user mailing list
> grass-user@lists.osgeo.org
> https://lists.osgeo.org/mailman/listinfo/grass-user
___
grass-user mailing list
grass-user@lists.osgeo.org
https://lists.osgeo.org/mailman/listinfo/grass-user

[GRASS-user] r.water.outlet map does not display

2017-03-06 Thread Rich Shepard

  Using r.watershed specifying the input DEM and a name for the drainage map
I can view the drainage map. When I follow this command with r.water.outlet
specifying the drainage map as input, 'watershed' as the output map name,
and the coordinates of the designated outlet, no map is displayable.

  Could this be due to the very flat nature of the terrain?

Rich
___
grass-user mailing list
grass-user@lists.osgeo.org
https://lists.osgeo.org/mailman/listinfo/grass-user