Feature Overlay (editing and combination)
Feature layers can also participate in the overlay process, but the types of analyses are different in different GIS software but they share many similarities.
In QGIS, Vector Overlay is accomplished through Vector Geoprocessing tools, documented here. These are the primary overlays, but many more exist.
Geometry modification only! QGIS warns that “this operation modifies only the features geometry. The attribute values of the features are not modified, although properties such as area or length of the features will be modified by the overlay operation. If such properties are stored as attributes, those attributes will have to be manually updated.” For example, you may have to use a tool to recalculate the areas of each polygon!
In ArcGIS Pro, similar processes can be implemented.
Here are some of the other types of feature overlay (from the Analysis/Overlay toolbox)
and others are possible in other programs (as seen here http://wiki.gis.com/wiki/index.php/Overlay). a dead link
Selection by location
(although this is also part of topic 6 “distance” analyses when one “selects within some distance)
In most GIS packages, selection of features within one layer based on features in another layer is a sort of “overlay” or multilayer query. This is known generally as an “intersect” operation, but has lots of variety of selection types and names in different platforms. Here are some of the possibilities in QGIS.
where A is the Circle layer and B is the rectangle layer.
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- Intersect – returns circles 1, 2 and 3.
- Contain – no circle returned, but if reversed, the rectangle would be returned because it contains circle 1. This is the opposite of “are within.”
- Disjoint- Only circle 4 is returned.
- Equal – No circles will be returned. (none exactly the same)
- Touch- circle 3 is returned.
- Overlap- circle 2 is returned.
- Are within- circle 1 is returned.
- Cross- complicated, but no circles will be returned.
edited by DJH Jan 15, 2026