Cutting features in ArcGIS 10

Question

What´s the easiest/smartest way of getting the opposite output of the clipping tool? I just need the area of feature A1 which is not covered by feature A2 in a new Layer/File. Now, I get the result by union´ing both features and deleting the "wrong" parts by hand.

Answer 1

You can useErase Tool in ArcToolBox. According to ESRI website :

"The Erase tool is used to perform overlay analysis on feature classes. This tool creates a feature class from those features or portions of features outside the erase feature class."

Have a look at this webpage, they have really nice explanations.

Answer 2

The ET GeoWizards toolset contains an Erase tool similar to the ArcGIS Erase,

Erases a feature layer with the features of a polygon layer

and is one of the free functions available to unregistered copies with no limitations.

Answer 3

use "Erase Features" in "XToolsPro - Extension for ArcGIS"

Answer 4

If you want a solution that does not involve any extra extensions or "high-grade" licences you can try this:

1. Union A1 and A2 to make A3.
2. Then select by location where A3 does not have its center in A2 (you may need to select A3 where it DOES have its centre in A2 and then switch selection). OR select by attributes as Union will append attributes from A1 and A2 to A3. This means it is very easy to identify which polygons are not covered by A2 by null attributes that have been acquired from A2.
3. Finally save selection to a new layer.

This process is actually easier than it sounds