[GRASSLIST:2381] best way to extract stream network

GRASS GRASS user
1

I am having a great deal of trouble extracting a useable stream layer from a DEM using r.terraflow. Using r.mapcalc and r.thin, I am able to derive a layer that can be converted to a vector, but the resulting stream network has all sorts of broken lines and capillary-like artifacts (see attached file). I would use r.watershed, but my coverage is too large (about 3000 x 3000). Any tips from others that have successfully derived stream layers in GRASS?

Thanks,
Chris
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Christopher J. Fonnesbeck ( c h r i s @ f o n n e s b e c k . o r g )
Georgia Cooperative Fish & Wildlife Research Unit, University of Georgia

(attachments)

stream.jpg

2

Here is a page with different command to extract river network:

http://skagit.meas.ncsu.edu/~helena/grasswork/grassclass/grass5tutor02/rflow.phtml

Chears, Max

Christopher Fonnesbeck wrote:

I am having a great deal of trouble extracting a useable stream layer from a DEM using r.terraflow. Using r.mapcalc and r.thin, I am able to derive a layer that can be converted to a vector, but the resulting stream network has all sorts of broken lines and capillary-like artifacts (see attached file). I would use r.watershed, but my coverage is too large (about 3000 x 3000). Any tips from others that have successfully derived stream layers in GRASS?

Thanks,
Chris
--
Christopher J. Fonnesbeck ( c h r i s @ f o n n e s b e c k . o r g )
Georgia Cooperative Fish & Wildlife Research Unit, University of Georgia

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note: change my e-mail reference to massimiliano.cannata@supsi.ch
      because the old one will be deleted soon.
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Ing. Massimiliano Cannata
Istituto di Scienze della Terra - SUPSI
C.P. 72 - CH-6952 Canobbio (Ticino, Switzerland)
Tel +41 91 /935 12 25 - Fax +41 91 /935 12 09
eMail: massimiliano.cannata@supsi.ch
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