Dissolve boundaries | Documentation

A dissolve analysis resulting in a new layer with a city boundary generated from neighborhood polygons.

What is a dissolve analysis?

A dissolve analysis is the process of combining polygons from feature datasetsFeature data is a general term for one or more features, which are records that represent real-world geographic entities, stored as a feature collection, feature layer, or hosted feature layer.Learn more that overlap or share a common boundary. To execute the analysis, use the spatial analysis serviceA spatial analysis service, also known as a feature analysis service, is a service used to perform spatial analysis operations on feature data such as finding, comparing, summarizing, analyzing patterns, and calculating geometries.Learn more and the DissolveBoundaries operation.

Dissolve boundaries analysis result showing merged overlapping or adjacent polygons.

Dissolve can also generate feature geometry and attribute summary statistics.

Real-world examples of this analysis include the following:

Creating a state or city boundary.
Creating contiguous sales regions based on the salesperson's name in each county.
Visualizing what points of interest or other features are within dissolved drive-time polygons.

How to perform a dissolve analysis

The general steps to performing a dissolve analysis are as follows:

Review the parameters for the DissolveBoundaries operation.
Send a request to get the spatial analysis service URL.
Execute a job request with the following URL and parameters:
- URL: https://<YOUR_ANALYSIS_SERVICE>/arcgis/rest/services/tasks/GPServer/DissolveBoundaries/submitJob
- Parameters:
  - inputLayer: The hosted feature layerA hosted feature layer is a hosted layer (item) in a portal that is used to manage the properties and settings of a spatially-enabled feature layer in a feature service.Learn more or feature collectionA feature collection is a data structure containing one or more features that share the same geometry type and set of attributes.Learn morecontaining polygon features that will be dissolved.
  - dissolveFields: One or more fields from the inputLayer that control which polygons are merged. If you don't supply dissolveFields, or you supply an empty list of fields, polygons that share a common border (that is, they are adjacent) or polygon areas that overlap will be dissolved into one polygon. The result will always include a Count field, which represents the number of input features that share the dissolve criteria.
  - outputName: A string representing the name of the hosted feature layer to return with the results.
Check the status.
Get the output layer results.

To see examples using ArcGIS API for Python, ArcGIS REST JS, and the ArcGIS REST API, go to Examples below.

URL request

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http://<YOUR_ANALYSIS_SERVICE>/arcgis/rest/services/tasks/GPServer/DissolveBoundaries/submitJob?<parameters>

Required parameters

Name	Description	Examples
`f`	The format of the data returned	`f=json` `f=pjson`
`token`	An access tokenAn access token is an authorization string that provides access to secure ArcGIS content, data, and services. Its capabilities are determined by the privileges it supports. It is obtained by implementing API key authentication, User authentication, or App authentication.Learn more (API key or OAuth 2.0) with the required Spatial Analysis > Feature analysis privilege.	`token=<ACCESS_TOKEN>`
`inputLayer`	The layer containing polygon features that will be dissolved.	`{"url": <SERVICE_URL>, "filter": <where clause>}` `{"layerDefinition": {}, "featureSet": {}, "filter": <where clause>}`

Key parameters

Name	Description	Examples
`dissolveFields`	One or more fields from the `inputLayer` that control which polygons are merged.	`"dissolveFields": ["Class"]`
`summaryFields`	A list of field names and statistical summary type that you wish to calculate from the polygons that are dissolved together	`"summaryFields": ["Annual_Sales Sum", "Annual_Sales Min"]`
`outputName`	A string representing the name of the hosted feature layerA hosted feature layer is a hosted layer (item) in a portal that is used to manage the properties and settings of a spatially-enabled feature layer in a feature service.Learn more 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

Dissolve boundaries by attribute value

This example uses the DissolveBoundaries operation to dissolve a hosted feature layer of township polygons based on their attribute values.

In the analysis, the inputLayer value is the Municipal Boundaries hosted feature layer. The dissolveFields value is specified as the field Class and multiPartFeatures is set to true. The results contain new Count and AnalysisArea fields containing the statistical details of the dissolve operation.

Dissolve analysis showing township polygons dissolved by an attribute value.

APIs

ArcGIS API for Python

ArcGIS REST JS

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inputLayer = "https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/Delaware_County_Municipal_Boundaries/FeatureServer/0"
dissolveField = "Class"

results = dissolve_boundaries(
    input_layer=inputLayer,
    multi_part_features=True,
    dissolve_fields=[dissolveField],
    # Outputs results as a hosted feature layer.
    output_name="Dissolve boundaries results",
)

result_features = results.layers[0].query()

print(f"Merged layer contains {len(result_features.features)} new records")

Go to tutorial

Service requests

Request

HTTP

cURL

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POST arcgis.com/sharing/rest/portals/self HTTP/1.1
Content-Type: application/x-www-form-urlencoded

&f=json
&token=<ACCESS_TOKEN>
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Response (JSON)

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{
  "helperServices": {
    // Other parameters
    "analysis": {
      "url": "https://{YOUR_ANALYSIS_SERVICE}/arcgis/rest/services/tasks/GPServer"
    }
  }
}

{
  "helperServices":{
    // Other parameters
    "analysis": {
      "url": "https://{YOUR_ANALYSIS_SERVICE}/{WEBADAPTOR_NAME}/rest/services/System/SpatialAnalysisTools/GPServer"},
  }
}

Request

HTTP

cURL

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POST <YOUR_ANALYSIS_SERVICE>/arcgis/rest/services/tasks/GPServer/DissolveBoundaries/submitJob HTTP/1.1
Content-Type: application/x-www-form-urlencoded

f=json
&token=<ACCESS_TOKEN>
&inputLayer={"url":"https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/Delaware_County_Municipal_Boundaries/FeatureServer/0"}
&multiPartFeatures=true
&dissolveFields=["Class"]
&outputName={"serviceProperties":{"name":"Dissovle boundaries results"}}

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Response (JSON)

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{
  "jobId": "<JOB_ID>",
  "jobStatus": "esriJobSubmitted",
  "results": {},
  "inputs": {},
  "messages": []

}

Request

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cURL

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POST <YOUR_ANALYSIS_SERVICE>/arcgis/rest/services/tasks/GPServer/DissolveBoundaries/jobs/<JOB_ID> HTTP/1.1
Content-Type: application/x-www-form-urlencoded

f=json
&token=<ACCESS_TOKEN>

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Response (JSON)

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{
  "jobId": "<JOB_ID>",
  "jobStatus": "esriJobSucceeded",
  "results": {
    "dissolvedLayer": {
      "paramUrl": "results/dissolvedLayer"
    }
  },
  "inputs": {},
  "messages": []
}

Request

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cURL

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POST <YOUR_ANALYSIS_SERVICE>/arcgis/rest/services/tasks/GPServer/DissolveBoundaries/jobs/<JOB_ID>/results/dissolvedLayer HTTP/1.1
Content-Type: application/x-www-form-urlencoded

f=json
&token=<ACCESS_TOKEN>

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Response (JSON)

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              "width": 1.5
            }
          }
        },
        "transparency": 25
      }
    }
  }
}