topic Re: Creating a dougnut hole in a polygon in Data Management Questions

Creating a dougnut hole in a polygon

WayneLyngholm — Thu, 17 Nov 2011 14:09:09 GMT

Greetings,

I need to digitize an "out" area in a forest vegetation polygon. The ArcGIS help directions are as follows:

Cutting donut holes in existing polygons

You can cut holes in existing polygon features to create a donut polygon.

Open the Snapping Environment dialog box and turn on snapping for edit sketch vertices. The check box is at the bottom of the dialog box. With edit sketch snapping, you can better construct a closed boundary defining the area you want to remove.

Set the task to Cut Polygon Features.

Click the Sketch tool .

Sketch the area you want to remove. Make sure the end vertex snaps to the first one, so you end up with a closed polygon.

Finish the sketch.

You now have two polygons. Select only the inner polygon and press the Delete key.

I cannot select the sketch tool when I have the task set to "Cut Polygon Features". Any suggestions? Thanks, TB

Re: Creating a dougnut hole in a polygon

JohnSobetzer — Fri, 18 Nov 2011 16:28:25 GMT

Which version of ArcGIS are you using? In 9x you need to select the polygon in order to cut it with the sketch tool. In addition you have to make sure it is the only selected polygon. If you install the Cut Polygons Without Selecting developer sample then these aren't a problem. In 10x if you have opted not to use feature templates, then the foregoing applies but you can't install that Developer Sample unfortunately. If you use feature templates you need to select the cut polygons tool.

Re: Creating a dougnut hole in a polygon

LeslieJacobs — Fri, 18 Nov 2011 18:59:54 GMT

Use the Erase tool under Analysis Tools > Overlay, to create a dougnut hole. Much easier than what you're trying to do.