Using ArcGIS 10.1 for Desktop is there a way to do a similar operation to creating a donut hole or island in a polygon without losing the existing features?
I have mapped small lakes as several different polygons based on vegetation type.
However, I want to map the vegetation surrounding the lakes, too – but if I create a circular polygon over the top of the lake and the surrounding area, it includes the area I've already mapped and given attributes to.
So I want to 'cut out' a hole in the middle of the new polygon without losing the polygons that are now covered by it.
Best Answer
Two ways spring to mind. The most efficient depends on how many inner polygons you have.
Clip: Select one of your existing 'lake' polygons then choose clip from the editor menu. Use a buffer distance of 0 and discard the area that intersects. This will clip a hole in any overlapping polygons. You will have to do this for each inner polygon.
Cut Polygon Tool: Select the overlapping polygon then choose 'cut polygon tool' from the editor toolbar. Use the trace tool to draw the outer limits of your inner polygons. This will cut the outer polygon into two pieces. Delete the inner piece to have a hole.