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Overlay Layers

Summary

Overlays the geometries from multiple layers into a single layer. Overlay can be used to combine, erase, modify, or update spatial features.

Overlay is used to answer one of the most basic questions of geography, What is on top of what? The following are examples:

  • What parcels are within the 100-year floodplain? (Within is another way of saying on top of.)
  • What land use is on top of what soil type?
  • What mines are within abandoned military bases?

Illustration

Overlay Layers

Usage

  • This geoprocessing tool is available with ArcGIS Enterprise 10.6.1 or later.

  • Use examples include the following:

    • The department of environmental quality wants to monitor the impact of grazing livestock on the state's water quality. Biologists with the department need to determine where the land deemed to be grazing allotments intersect certain watersheds. Overlay Layers can be used to find intersecting areas.
    • A development company wants to build a 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 that they may be able to purchase for the resort. Overlay Layers can be used to remove the publically owned lands from the selected counties.

  • With ArcGIS Enterprise 10.6.1, the input layer and overlay layer must have matching geometry types. At ArcGIS Enterprise 10.7, additional relationships are supported.

  • The following table outlines the Intersect and Erase overlay operations with different geometry types available at ArcGIS Enterprise 10.6.1:

    Input layer (green) and overlay layer (yellow)Intersect resultsErase results
    Input and overlay polygons

    Polygon overlay layer (green) and input layer (yellow).

    Polygon feature results using Intersect

    Intersecting polygons of the input and overlay layers. B is the intersection of B and 2. D is the intersection of D and 4. E is the intersection of E and 5.

    Polygon feature results using Erase

    Polygons that are the result of the Erase operation. E has been completely erased, and a portion of B and D have been erased. A and C have not been erased.

    Input and overlay lines

    Line overlay layer (green) and input layer (yellow).

    Line feature results using Intersect

    Lines that are the result of the Intersect operation. B is the intersection of B and 2. D is the intersection of D and 4.

    Line feature results using Erase

    Lines that are the result of the Erase operation. The feature B has been completely erased and a segment of D has been erased. A and C have not been erased.

    Input and overlay points

    Point overlay layer (green) and input layer (yellow).

    Point feature results using Intersect

    A point that is the result of the Intersect operation. C is the intersection of C and 3.

    Point feature results using Erase

    Points that are the result of the Erase operation. The feature C has been erased. A and B are the result of the operation.

  • With ArcGIS Enterprise 10.6.1, if both layers are polygons, analysis can be accelerated by unchecking the Include Overlapping Input Layers parameter (include_overlaps=NOT_OVERLAPPING in Python). You should only uncheck this input if both of the following conditions are true:

    • The input layer features do not overlap other input layer features.
    • The overlay layer features do not overlap other overlay layer features.

    You can also uncheck this parameter if you don't want a unique result returned for each self-intersecting overlap. For example, census boundaries would not have any self-overlapping features, and if they were overlaid to another disjoint polygon layer, you could uncheck this parameter. This parameter is not used at ArcGIS Enterprise 10.7 or later.

  • At ArcGIS Enterprise 10.7 or later, the supported overlay methods and input geometries are described in the following table:

    Input and Overlay geometry typesIntersectEraseUnion (available at 10.7)Identity (available at 10.7)Symmetric Difference (available at 10.7)

    Point and point

    Check mark

    Available at 10.6.1 and later.

    Check mark

    Available at 10.6.1 and later.

    Check mark

    Available at 10.7 and later.

    Check mark

    Available at 10.7 and later.

    Point and polyline

    Check mark

    Available at 10.7 and later.

    Point and polygon

    Check mark

    Available at 10.7 and later.

    Check mark

    Available at 10.7 and later.

    Polyline and point

    Check mark

    Available at 10.7 and later.

    Polyline and polyline

    Check mark

    Available at 10.6.1 and later.

    Check mark

    Available at 10.6.1 and later.

    Check mark

    Available at 10.7 and later.

    Check mark

    Available at 10.7 and later.

    Polyline and polygon

    Check mark

    Available at 10.7 and later.

    Check mark

    Available at 10.7 and later.

    Polygon and point

    Check mark

    Available at 10.7 and later.

    Polygon and polyline

    Check mark

    Available at 10.7 and later.

    Polygon and polygon

    Check mark

    Available at 10.6.1 and later.

    Check mark

    Available at 10.6.1 and later.

    Check mark

    Available at 10.7 and later.

    Check mark

    Available at 10.7 and later.

    Check mark

    Available at 10.7 and later.

    Overlay methodDescription

    Intersect

    Intersect

    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.

    This is the default.

    Erase

    Erase

    The features or portions of features in the overlay features that overlap the input features are removed.

    Union

    Union

    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.

    Identity

    Identity

    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.

    Symmetric Difference

    Symmetric Difference

    The result will contain features or portions of features of the input layer and the overlay layer that do not overlap.

Syntax

OverlayLayers(input_layer, overlay_layer, output_name, overlay_type, {include_overlaps}, {data_store})
ParameterExplanationData Type
input_layer

The point, line, or polygon features that will be overlaid with the overlay layer.

Feature Set
overlay_layer

The features that will be overlaid with the input layer features.

Feature Set
output_name

The name of the output feature service.

String
overlay_type

Specifies the type of overlay to be performed.

  • INTERSECTComputes a geometric intersection of the input layers. Features or portions of features that overlap in both the input layer and overlay layer will be written to the output layer. This is the default.
  • ERASEOnly those features or portions of features in the overlay layer that are not within the features in the input layer are written to the output.
  • UNION Computes a geometric union of the input layer and overlay layer. All features and their attributes will be written to the layer.
  • IDENTITY Computes a geometric intersection of the input features and identity features. Features or portions of features that overlap in both input layer and overlay layer will be written to the output layer.
  • SYMMETRICAL_DIFFERENCE Features or portions of features in the input layer and overlay layer that do not overlap will be written to the output layer.
String
include_overlaps
(Optional)

Specifies whether one or both of the input layers have overlapping features.

  • OVERLAPPINGOne or both of the layers have overlapping features. This is the default.
  • NOT_OVERLAPPINGNeither layer has overlapping features.
Boolean
data_store
(Optional)

Specifies the ArcGIS Data Store where the output will be saved. The default is SPATIOTEMPORAL_DATA_STORE. All results stored to the SPATIOTEMPORAL_DATA_STORE will be stored in WGS84. Results stored in a RELATIONAL_DATA_STORE will maintain their coordinate system.

  • SPATIOTEMPORAL_DATA_STOREOutput will be stored in a spatiotemporal big data store. This is the default.
  • RELATIONAL_DATA_STOREOutput will be stored in a relational data store.
String

Derived Output

NameExplanationData Type
output

The overlay of multiple layers into a single layer.

Feature Set

Code sample

OverlayLayers example (stand-alone script)

The following Python window script demonstrates how to use the OverlayLayers tool.

#-------------------------------------------------------------------------------
# Name: OverlayLayers.py
# Description: Remove areas that are already developed from proposed development sites
#
# Requirements: ArcGIS GeoAnalytics Server

# Import system modules
import arcpy

# Set local variables
inFeatures = "https://myGeoAnalyticsMachine.domain.com/geoanalytics/rest/services/DataStoreCatalogs/bigDataFileShares_cityData/BigDataCatalogServer/areasOfInterest"
overlayFeatures = "https://myGeoAnalyticsMachine.domain.com/geoanalytics/rest/services/DataStoreCatalogs/bigDataFileShares_cityData/BigDataCatalogServer/commercial"
outFS = "DevelopmentSites"
overlayType = "ERASE"
dataStore = "SPATIOTEMPORAL_DATA_STORE"

# Execute Overlay Layers
arcpy.geoanalytics.OverlayLayers(inFeatures, overlayFeatures, outFS, 
                                 overlayType, dataStore)

Environments

Output Coordinate System

The coordinate system that will be used for analysis. Analysis will be completed in the input coordinate system unless specified by this parameter. For GeoAnalytics Tools, final results will be stored in the spatiotemporal data store in WGS84.

Licensing information

  • Basic: Requires ArcGIS GeoAnalytics Server
  • Standard: Requires ArcGIS GeoAnalytics Server
  • Advanced: Requires ArcGIS GeoAnalytics Server

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