I have a "park area" shapefile and a "lake" shapefile both consisting of polygons. There are some areas where the park area polygons do not entirely match the borders of the lake polygons due to data collection inconsistencies, even though the park area should match the lake outline completely. I am wondering if there is a way to properly extend the park area polygons in certain locations so they follow the outline of the lakes. I have attempted to use the Draw functions in ArcGIS for Desktop to no avail. I am not overly concerned with the accuracy of the park area polygons as this editing is for cartographic purposes, so if the park area ends up "inside" the water bodies it isn't an issue, but if there is a way to make the park area polygon automatically end at a lake border that would be preferable. Below is an image showing the issue I am having - The yellow background "sticks out" underneath the park area polygon at points it should not.

enter image description here


The quickest process to solve your problem is to use a combination between Symmetrical Difference and Merge tools in ArcGIS, however, to use Symmetrical Difference tool you should have ArcInfo License. If you don't have ArcInfo license, then QGIS is your friend in this case.

You can do it using the following steps:

  1. Use the yellow background polygon as a base if its extent covers both the lake and the park area.
  2. Use the difference tool two times:

    (a) In the input use the yellow polygon as input and the park as the difference polygon, and save the output poylgon

    (b) Use the out polygon from step (a) as input, and the lake area as the difference polygon, and save the output to a new file.

  3. Use Merge tool to merge the output from step (b) with the lake polygon to extend the lake to edge of the park.

The above process is a general process, you can adjust it based on the data that you have.

  • 1
    I believe the old ArcInfo license is now Advanced license – Midavalo May 16 '16 at 6:48
  • It is true. I followed what is written in the Symmetrical Difference tool of "This topic applies to ArcInfo only" to avoid any confusion. – ahmadhanb May 16 '16 at 6:50
  • 1
    A symmetrical difference in ArcGIS for Desktop can be done with a Basic level license by using Union then Select. – PolyGeo May 16 '16 at 6:50
  • Thanks for the solution - I appreciate it. I have been able to edit a few locations like this, but anything that is cut off by the map's extent doesn't seem to play well with the Symmetrical Difference tool. Do you have any advice on how to handle this? – Dylrch May 16 '16 at 7:21
  • You can create a new background polygons for other parts, then use the same process again. – ahmadhanb May 16 '16 at 7:48

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