I have a set of international borders that I would like to overlay on top of a different data layer that represents coastlines ("land" essentially). I would like to convert my Admin 0 polygons into linestrings and then remove all of the coastlines, leaving only the internal boundaries in place. Is this something I can do with GRASS?
My thought was that it should be possible to look for any line which is not a shared border between 2 features, tag it somehow, and delete it.
Thanks in advance for your help.