Is there any way to generate a stream network (vector file) from within
GRASS based on a DEM?
--j
--
Jonathan A. Greenberg, PhD
NRC Research Associate
NASA Ames Research Center
MS 242-4
Moffett Field, CA 94035-1000
Office: 650-604-5896
Cell: 415-794-5043
AIM: jgrn3007
MSN: jgrn3007@hotmail.com
R.watershed + r.to.vect
Michael
__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution and Social Change
Arizona State University
Tempe, AZ 85287-2402
phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton
From: Jonathan Greenberg <jgreenberg@arc.nasa.gov>
Date: Sat, 25 Feb 2006 20:44:49 -0800
To: 'GRASS user list' <grasslist@baylor.edu>
Subject: [GRASSLIST:10575] Stream network in GRASS?Is there any way to generate a stream network (vector file) from within
GRASS based on a DEM?--j
--
Jonathan A. Greenberg, PhD
NRC Research Associate
NASA Ames Research Center
MS 242-4
Moffett Field, CA 94035-1000
Office: 650-604-5896
Cell: 415-794-5043
AIM: jgrn3007
MSN: jgrn3007@hotmail.com
Michael:
Thanks! I was playing with r.watershed today, and running it on a
tutorial DEM from the DHSVM hydro modeling toolkit was resulting in the
streams output from r.watershed (which I'm assuming I would use to create
the vector) had values for every cell, not just the valley/stream cells. Is
there a way to have a grid of only "river" cells, not all flowlines created
from the dem?
--j
--
Jonathan A. Greenberg, PhD
NRC Research Associate
NASA Ames Research Center
MS 242-4
Moffett Field, CA 94035-1000
Office: 650-604-5896
Cell: 415-794-5043
AIM: jgrn3007
MSN: jgrn3007@hotmail.com
-----Original Message-----
From: owner-GRASSLIST@baylor.edu [mailto:owner-GRASSLIST@baylor.edu] On
Behalf Of Michael Barton
Sent: Saturday, February 25, 2006 10:25 PM
To: Jonathan Greenberg; Multiple recipients of list
Subject: [GRASSLIST:10578] Re: Stream network in GRASS?
R.watershed + r.to.vect
Michael
__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution and Social Change
Arizona State University
Tempe, AZ 85287-2402
phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton
From: Jonathan Greenberg <jgreenberg@arc.nasa.gov>
Date: Sat, 25 Feb 2006 20:44:49 -0800
To: 'GRASS user list' <grasslist@baylor.edu>
Subject: [GRASSLIST:10575] Stream network in GRASS?Is there any way to generate a stream network (vector file) from within
GRASS based on a DEM?--j
--
Jonathan A. Greenberg, PhD
NRC Research Associate
NASA Ames Research Center
MS 242-4
Moffett Field, CA 94035-1000
Office: 650-604-5896
Cell: 415-794-5043
AIM: jgrn3007
MSN: jgrn3007@hotmail.com
Scrive Jonathan Greenberg <jgreenberg@arc.nasa.gov>:
Thanks! I was playing with r.watershed today, and running it on a
tutorial DEM from the DHSVM hydro modeling toolkit was resulting in the
streams output from r.watershed (which I'm assuming I would use to create
the vector) had values for every cell, not just the valley/stream cells. Is
there a way to have a grid of only "river" cells, not all flowlines created
from the dem?
Just play with r.reclass until you can separate cell values into river/non-river
classes. That should be easy.
Regards,
Steko
--
Stefano Costa
http://www.iosa.it * Software Libero per l'Archeologia
Jabber: steko@jabber.linux.it
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Hi,
Check out r.terraflow --> reclass the topographic index output map.
See example here:
http://casoilresource.lawr.ucdavis.edu/drupal/node/166
Also try:
r.flow
r.topmodel
Dylan
On 2/26/06, Stefano Costa <steko@iosa.it> wrote:
Scrive Jonathan Greenberg <jgreenberg@arc.nasa.gov>:
> Thanks! I was playing with r.watershed today, and running it on a
> tutorial DEM from the DHSVM hydro modeling toolkit was resulting in the
> streams output from r.watershed (which I'm assuming I would use to create
> the vector) had values for every cell, not just the valley/stream cells. Is
> there a way to have a grid of only "river" cells, not all flowlines created
> from the dem?Just play with r.reclass until you can separate cell values into river/non-river
classes. That should be easy.Regards,
Steko--
Stefano Costa
http://www.iosa.it * Software Libero per l'Archeologia
Jabber: steko@jabber.linux.it----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.
Check out r.terraflow --> reclass the topographic index output map.
See example here:
http://casoilresource.lawr.ucdavis.edu/drupal/node/166Also try:
r.flow
r.topmodel
One idea I've been playing around with-
Treat accum output map as a DEM, then use 'r.param.scale param=feature'
to classify the ridges. Then r.mapcalc to turn the ridge areas into a
MASK, r.thin, etc.
Really what I've been trying to do is calculate width of a river. So far
I've been able to use the polygon to a distance_to_shore map using
r.cost which gives me something of similar shape to a river flow map,
then above proceedure & double the center line value and grow that out
to the shore using r.grow & a cellular automata loop. This should end up
with a raster layer showing the width. I'm trying to avoid arbitrarily
drawing a line down the axis of the polygon & doing the right-angle line
crossing polygon calculations..
Hamish