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Converting polygons to lines and deleting external boundaries

July 26 2010 | 0 comments
Categories: Map Data

I am working with data with different countries and trying to convert polygons showing administrative divisions to lines and delete external boundaries for symbolizing internal boundaries differently from external boundaries. I found these instructions very useful:

http://mappingcenter.esri.com/index.cfm?effect=Coast%20Lines&fa=maps.europeEnergy

However, the data I'm using has topology errors so once I merge polygons and convert to line showing only external boundaries I end up having some extra lines here and there. Therefore, the selection from administrative lines (converted from polygons) won't be succesful with this data because some of the internal lines will be selected, too.

So my question is: Is there a way of selecting just external boundaries from this data with topology errors? Is there a way of recognizing which boundaries are external and which are not? I'm trying to save time and skip the topology errors cleaning part because I have to do this pretty often.

Not to make this too easy I am also trying to find a solution that could be done with ArcView license and that is why using coverage is not a solution. For what I've understood Features tools used here are not available in ArcView either. Do you have a solution for this?

Thank you very much in advance.

Mapping Center Answer:

I cannot think of a way, other than Merge, to get these external only boundaries.  If you already tried this and still have data problems, I think the only thing left for you is to go through and do the clean up.

That said, don't forget that there is also a data set that is included in your software disks that is the ESRI Data and Maps DVD -- on this, there is a dta set for the world called admin_ln that includes administrativel lines and has an attribute called BND_TYPE which includes: internal administrative lines, coastlines, international boundaries and median lines.

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