An overlay analysis resulting in a new layer with properties (and partial property areas) that intersect flood zones.
What is an overlay analysis?
An overlay analysis is the process of combining two or more feature datasets using either intersect, union, or erase methods. To execute the analysis, use the spatial analysis service and the OverlayLayers operation.
The overlay methods you can use depends on whether the input and overlay feature layers are points, polylines, or polygons.
When using the Erase overlay method, the input features must be of the same or lesser order feature type of the overlay layer. The following erase options are supported:
A point feature can be erased by point, line, or area features.
A line feature can be erased by line or area features.
An area feature can be erased by area features.
The table below outlines each overlay method:
Overlay method
Input features
Overlay features
Description
Intersect
Points, Polylines, or Polygons
Points, Polylines, or Polygons
The input features (or portions of features) that overlap with the overlay features are kept.
Union
Polygons
Polygons
The input and overlay areas are combined.
Erase
Points
Points, Polylines, or Polygons
The input features (or portions of features) that do not overlap with the areas in the overlay layer are erased.
Polylines
Polylines, or Polygons
Polygons
Polygons
The type of result features will depend on the overlay method and inputs. All of the attributes from the input and overlay feature data will be carried over to the result feature data.
Real-world examples of this analysis include the following:
Determining which parcels are within the 100-year floodplain.
Finding what types of roads are within a county.
Locating the wells that are within an abandoned military base.
How to perform an overlay analysis
The general steps to performing an overlay analysis are as follows:
Review the parameters for the OverlayLayers operation.
Send a request to get the spatial analysis service URL.
Execute a job request with the following URL and parameters:
The point, line, or polygon features that will be overlayed with the overlayLayer parameter.
{"url": <SERVICE_URL>, "filter": <where clause>}
overlayLayer
The features that will be overlaid with the inputLayer parameter features.
{"url": <SERVICE_URL>, "filter": <where clause>}
Key parameters
Name
Description
Examples
overlayType
The type of overlay to be performed. [Intersect, Union, Erase]
"overlayType": "Union"
outputType
The type of intersection to be found. This parameter is only valid when the overlayType parameter value is Intersect. [Input,Line,Point]
"outputType":"Line"
outputName
A string representing the name of the hosted feature layer to return with the results. NOTE: If you do not include this parameter, the results are returned as a feature collection (JSON).
{"serviceProperties": {"name": "<SERVICE_NAME>"}}
Example
Overlay parks with bike paths
This example uses the OverlayLayers operation to find areas of parks that are within 500 feet of bike routes.
In the analysis, the inputLayer value is the Park polygons hosted feature layer. The overlayLayer value is the 500 foot Buffer of bike routes. The overlayType value uses the default intersect method.
Learn how to perform related analyses interactively with Map Viewer and programmatically with ArcGIS API for Python, ArcGIS REST JS, and ArcGIS REST API.