I'm unsuccessfully trying to make a bathymetric map with contours extracted from Lidar data at 1 m resolution. The extracted contours have a lot of artifacts like dangles and islands.
First I used QGIS/GRASS 1.8 with v.clean, running the rmdangle which successfully removed a large part of dangles. But it also created some holes in the main line, and the snapping algorithm don't work well because it's snapping the wrong vertices.
Then, after a few manual operations, the algorithms of Sextante doesn't work anymore and I have an error message : Could not load layer...
So I use ArcGIS 10 for build the topology, but I don't success repairing it. When I try trim or snap, it doesn't work at all.
To conclude I can't remove all the "islands" and other artifacts like intersections. I think I've tried all I know... And I can't do it manually for the whole study area!
Does anybody have a solution for it?
Thank you very much.