Hi,
I’ve labeled contour (DEM) map using d.vect. Now I would like to find the depression [contour with low elev value are inside the contour of higher elev] automatically. I can view it in the Map display window which is tedious as I’ve to zoom in and out for several times.
Is there any method available in GRASS?
Thanks in advance!
On Sun, Dec 11, 2016 at 5:01 AM, Faisal Kabir <faisal.kabir@gmail.com> wrote:
Hi,
I've labeled contour (DEM) map using d.vect. Now I would like to find the
depression [contour with low elev value are inside the contour of higher
elev] automatically. I can view it in the Map display window which is
tedious as I've to zoom in and out for several times.Is there any method available in GRASS?
Yes: in r.fill.dir for example.
I have taken your question as motivation to add an example to the
manual page and updated it on the GRASS GIS Web server right away:
https://grass.osgeo.org/grass72/manuals/r.fill.dir.html#examples
It shows how to run sink-filling and how to identify the filled areas.
Please note that filling depressions is not needed nor desired when
calculating watersheds with r.watershed in case that this is your
scope.
Best,
Markus
--
Markus Neteler
http://www.mundialis.de - free data with free software
http://grass.osgeo.org
http://courses.neteler.org/blog
There is a useful addon for this: r.geomorphon .
An alternative can be also
r.param.scale
Best
Ivan
Il Dom 11 Dic 2016, 13:22 Markus Neteler <neteler@osgeo.org> ha scritto:
On Sun, Dec 11, 2016 at 5:01 AM, Faisal Kabir <faisal.kabir@gmail.com> wrote:
Hi,
I’ve labeled contour (DEM) map using d.vect. Now I would like to find the
depression [contour with low elev value are inside the contour of higher
elev] automatically. I can view it in the Map display window which is
tedious as I’ve to zoom in and out for several times.Is there any method available in GRASS?
Yes: in r.fill.dir for example.
I have taken your question as motivation to add an example to the
manual page and updated it on the GRASS GIS Web server right away:https://grass.osgeo.org/grass72/manuals/r.fill.dir.html#examples
It shows how to run sink-filling and how to identify the filled areas.
Please note that filling depressions is not needed nor desired when
calculating watersheds with r.watershed in case that this is your
scope.Best,
Markus–
Markus Neteler
http://www.mundialis.de - free data with free software
http://grass.osgeo.org
http://courses.neteler.org/blog
grass-user mailing list
grass-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/grass-user
–
Sent by smartphone
On Dec 11, 2016 2:29 PM, “Ivan Marchesini” <ivan.marchesini@gmail.com> wrote:
There is a useful addon for this: r.geomorphon .
I still don’t remember why we don’t move it at least to trunk.
An alternative can be also
r.param.scale
Yes. Importantly, all of them use different methods. Would be nice to see the new example transferred to the other manual pages, too, for comparison purposes…
Markus
On Sun, Dec 11, 2016 at 3:13 PM, Stuart Edwards <stuarte9@icloud.com> wrote:
On Dec 11, 2016, at 7:22 AM, Markus Neteler <neteler@osgeo.org> wrote:
...
I have taken your question as motivation to add an example to the
manual page and updated it on the GRASS GIS Web server right away:https://grass.osgeo.org/grass72/manuals/r.fill.dir.html#examples
It shows how to run sink-filling and how to identify the filled areas.
...
That's a very nice result - I've struggled with this problem in the past. Arc has a function 'sink' that simply provides a map of - you guessed it - sinks, and in the FOSS world, Whitebox has a similar (actually better) function that I generally resort to.
Now you know three more 
r.fill.dir., r.param.scale and r.geomorphon
https://grass.osgeo.org/grass72/manuals/r.fill.dir.html
https://grass.osgeo.org/grass72/manuals/r.param.scale.html
https://grass.osgeo.org/grass70/manuals/addons/r.geomorphon.html
It would be nice to have a real GRASS 'sink' function - especially useful for the study of karst landscapes.
A simple wrapper script would do the job I suppose.
Markus