The Overlay Layers tool combines two layers into a single layer using various methods including intersect, erase, union, identity, and symmetrical difference.
- The department of environmental quality wants to monitor the impact of livestock grazing on the state's water quality. Biologists with the department need to determine where the land deemed to be grazing allotments intersects with certain watersheds. Overlay layers via an intersect operation can be used to find intersecting areas.
- A development company wants to build a new golf resort in one of three centrally located counties in their state. Before they can begin planning, they need to determine whether there is enough privately owned land within those counties available to purchase for the resort. Overlay layers via an erase operation can be used to remove the publicly owned lands from the selected counties.
- Sliver features may be excluded based on the tolerance of the processing spatial reference.
- The following table outlines the available overlay operations per input and overlay geometry types:
Input and overlay geometry types Intersect Erase Union Identity Symmetric difference
Point and point
Point and polyline
Point and polygon
Polyline and point
Polyline and polyline
Polyline and polygon
Polygon and point
Polygon and polyline
Polygon and polygon
- The supported overlay methods and input geometries are described in the following table:
Overlay method Description
The features or portions of features in the overlay that overlap the input features are preserved. The input and feature geometry must be the same.
The features or portions of features in the overlay features that overlap the input features are removed.
The result will contain a geometric union of the input layer and overlay layer. All features and their attributes will be written to the layer.
The result will contain features or portions of features of the input features and overlay features. Features or portions of features that overlap in both input layer and overlay layer will be written to the output layer.
The result will contain features or portions of features of the input layer and the overlay layer that do not overlap.
The input layer for the overlay operation.
The overlay layer for the overlay operation.
Specifies the type of overlay to be performed. Overlay operations include:
The output layer will retain the same schema of the input layer.
Considerations and limitations
- Input and overlay layers may be point, line, or polygon features.