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I want to emphasize only shared provincial boundaries. Are there any techniques for doing this in ArcMap?

November 01 2007 | 0 comments
Categories: ArcGIS Methods, Data Modeling, Symbology

I'm working with a population density map of Canada, where units are aggregated to what is called a "census subdivision" level. I also want to delineate province boundaries. Easy--put the Provinces layer above the CensusSubDiv layer and symbolize it with a hollow fill and a
thicker outline. The problem is the thicker outline works fine for delineating internal province boundaries (like Alberta from Saskatchewan)but it makes all the outer boundaries, such as coastlines and all the numerous northern islands undesirably prominent. See attached graphic. I want to emphasize only shared provincial boundaries. Are there any techniques for doing this in ArcMap? 1) I guess a kindasorta solution would be to use a more generalized provinces layer, but that's not really what I want. 2) I think there may be a solution with cartographic representations using the Suppress Outline geometric effect (developer sample), but this is too advanced for my materials, which are being developed for an ArcView-license introductory training class. Thanks for any ideas.

Attachment: CanadaWithThickOutlines.gif

Mapping Center Answer:

Traditionally, such a map may or may not have had a coastline symbolized, but if it did it would have been a light blue line, and then there would have been other classes of boundaries; international and province. The solution is to use lines; to get these lines do the following:

1. Use the Polygon to Line tool with your provinces as the input. This will produce a line dataset that needs an additional attribute to denote what kind of line is there.
2. Add a new field (either type of integer field will work. Using the interactive selection tool select and calculate the following values into this new field (if you’re sharing the data use a domain so others can follow what you did):

     a. International Land: All land international boundaries; Alaska, and along the northern U.S. States.
     b. International Water: within the U.S. Great Lakes and in upper Minnesota
     c. Internal Province: All non-coastal province boundaries. These should be easy to select by dragging a rectangle around the interior of the Western provinces and grab the others as one-offs
     d. Coastlines: The remainder should be of this type.

Now you can symbolize each kind of line as needed, with the option to not draw the coastlines (probably the best option for this map).

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