If you need a centerline of a river system, i have a shell script for you.
To derive a centerline of a polygon you can use the v.centerline.sh (download at http://www.uibk.ac.at/geographie/personal/michael_vetter). The script needs an input polygon as a grass boundary and calculates a centerline of the polygon (output of r.thin and some v.clean tools). you have to change the cleaning parameters (thresh and smooth) to get a nice centerline. If your resolution is to small, you will have a very bad performance (because of r.thin). Michael Jonathan Greenberg-2 wrote: > > I have a large, complex single polygon (with donuts) that represents the > boundary of the Sacramento Bay Delta rivers -- I would like to generate > a line network running down the center of this boundary, but I'm having > a hard time accomplishing this. Any ideas? I believe this is referred > to as the polygon "skeleton". > > --j > > > -- > > Jonathan A. Greenberg, PhD > Postdoctoral Scholar > Center for Spatial Technologies and Remote Sensing (CSTARS) > University of California, Davis > One Shields Avenue > The Barn, Room 250N > Davis, CA 95616 > Cell: 415-794-5043 > AIM: jgrn307, MSN: [EMAIL PROTECTED], Gchat: jgrn307 > _______________________________________________ > grass-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-user > > -- View this message in context: http://www.nabble.com/Water-boundaries-to-stream-network...-tp15645454p15654604.html Sent from the Grass - Users mailing list archive at Nabble.com. _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
