Hi all, Hopefully a simple question for you. I'm using ArcInfo 9.31. I have a polygon feature class of watersheds which have been divided up into subwatersheds. So the base feature is a tributary to one of a number of larger streams in town. The features all include a field for a "primary watershed" - basically allowing us to group the subatersheds into one stream's overall watershed.
So the question is this: How do I DISPLAY just the outline of the larger, primary watersheds, without showing the boundaries of the subwatersheds inside?
I need a solution that is just a display setting for producing maps, which deosn't involve editing or geoprocessing the data. Both the original watersheds (divided to subwatershed) and the grouped watersheds (primary watersheds) will continue to be used into the future, for maps and for general GIS use. We also expect these watershed boundaries to change in the near future as we collect more information, so I really don't want to have to try to keep two parallel datasets - one if primary watersheds and one of subwatersheds - geometrically identical.
I'm not aware of any functionality which would allow you to achieve this goal without dissolving or merging your dataset.
I know that there isn't any functionality included with cartographic representations that would give you the output you desire. Representation symbology works just like standard symbology with polygons. The symbol draws to the edge of the polygon; if the larger (dissolved) polygon isn't in the data, it can't be used for display purposes.
I initially just had an outline symbol so I didn't do the multi-level symbol as outlined in the help. I've gone back through, step-by-step, and now I am getting mixed results. If I specify a fill color for the top symbol, then the joining works perfectly and I get essentially the desired result. If I specify a "no color" fill for the top symbol, the symbology reverts back to the default where there is no joining and al lthe boundaries show. Any thought on this?
I'll continue trying different variables and see if I can get it to work. Thanks agian for taking the time to help me out!
Yes, we want these shown as just boundaries with other data "underneath". I'll try your suggestion, but it might not work out in this aprticular case.
For what its worth, I spent a bunch of time researching representations and if it would be possible via that route. The "Cut" geometric tool seemed the most promising, but I couldn't quite get it working right.
As before, if I do find a solution, I'll be sure to post it! Thanks again, Sean