Okay, so I have 2 shapefiles:
- US states outline file (very coarse/simple outlines)
- Global Self-consistent Hierarchical High-resolution Shorelines, Level F (much finer spatial resolution)
I am trying to make a map series for my employer using the GSHHS as my land/not land background, and overlaying the state outlines over top. I have other layers, but they're not relevant to this discussion.
This is what the smallest North America polygon looks like.
I am only interested in the western US, and only need a couple hundred miles into Mexico and Canada for background purposes.
I can't simply
clip for obvious reasons, and there's another problem...
In both cases, the GCHHS runs inside as well as outside the rough state lines. I'd like to update the shoreline of the state file to match the GCHHS.
The only theoretical way I've come up with would be to do an
Erase of the GCHHS based on the states, which would give me the bits outside the states, then maybe a
Clip of the states based on the GCHHS to get the bits where the states overrun.
And once I get all these slivers, I'd have to dissolve them all into the proper state.
Should I just start looking for higher-resolution state polygons?
Thanks for any ideas or suggestions.