2011

Tell me more
Video
■ Show me how to create an overlay ana-
lysis for features
Tutorial
■ Lesson 4: Perform a Flood Analysis with
Overlay
■ Lesson 5: Edit a Predefined Workflow
Procedures
■ To perform an Overlay operation (page
1316)
GIS Skills
■ Create an overlay analysis for features.
Related topics
■
Overlaying Two Topologies (page 1336)
Attributes in the Resulting Layer
Use the
Split and Merge Rules dialog box (page 1669) to set attributes for layers
that are split as a result of an overlay operation. If you do not set these rules,
such features follow default rules. Merge rules do not apply. If you overlay
two feature sources that you used previously in a different map, you must
reset the rules for the new map.
In some cases, attributes from both the Source and Overlay are written to the
output. If this results in attributes that have the same name, each one will
have the original attribute name and a numeric suffix. For example, you can
overlay two layers called Cities and Parcels. If both have a Name attribute, the
resulting layer will have attributes called “Name_1” and “Name_2.”
Selecting Source and Overlay Geometries
The geometry in the feature classes or layers you select determines the other
choices in the dialog box. You can combine only certain types of geometries.
For example, Union and Symmetric Difference support polygon/polygon
comparisons only. Also, you cannot choose point geometries for both Source
and Overlay. If you select point geometry for Source, you can select only
polygon geometry for Overlay.
1310 | Chapter 8 Analyzing Data