I would like to snap these two polygons so that my city boundary lines up with the fire district boundary as much as possible.

When using the Snap geoprocessing tool, what is the best way to determine a value for the distance parameter?

City boundaries are green and fire districts are red.

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closed as primarily opinion-based by PolyGeo Sep 16 '16 at 23:29

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise. If this question can be reworded to fit the rules in the help center, please edit the question.

  • if you know that fire boundary completely covers the city and also fire boundary file has higher accuracy, you'd dissolve fire boundary polygons into one to make city boundary – yosukesabai Mar 3 '16 at 17:52
  • I would like to maintain each polygon. If I dissolve it, the fire polygon will only be a single feature. – Geoffrey West Mar 3 '16 at 18:33
  • 1
    The best way to find the distance is to use the measure tool.... The GP snap tool doesnt always give you the results you expect. Depending on the complexity of the data you can get better results fixing it interactively with the align edge or align to shape tools within the editor. – Sean Jones Mar 3 '16 at 19:00

It's totally subjective. There is no "best" way. It's a matter of how much error you're willing to accept--keeping in mind how it will impact later processes in your workflow.


I ended up using the the editor tool, reshape and trace. Answer can be found here.


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