ArcGIS REST API

Watershed

Watershed task

The Watershed task determines the contributing area above a set of cells in a raster.

The value of each watershed will be taken from the value of the source in the input raster or feature pour point data. When the pour point is a raster, the cell values will be used. When the pour point is a point feature, the values from the specified field will be used.

Request URL

https://<raster analysis url>/Watershed/submitJob

Request Parameters

The following table lists the parameters with syntax and details for each.

ParameterDescription

inputFlowDirectionRaster

(Required)

The input raster that shows the direction of flow out of each cell.

Syntax: This parameter can be specified as a Portal Item ID, a URL to a raster image service layer, or a cloud raster dataset.

Examples:

  • "inputFlowDirectionRaster": {"itemId": <portal item id>}
  • "inputFlowDirectionRaster": {"url": <image service layer url>}

inPourPointData

(Required)

The input pour point locations.

For a raster, this represents cells above which the contributing area, or catchment, will be determined. All cells that are not NoData will be used as source cells. For a point input, this represents locations above which the contributing area, or catchment, will be determined.

Raster input

Syntax: This parameter can be specified as a Portal Item ID, a URL to a raster image service layer, or a cloud raster dataset.

Domain: Integer raster

Examples:

  • "inPourPointData":{"itemID": <portal item id>}
  • "inPourPointData":{"url": <image service layer url>}

Feature input

Syntax: This parameter can be specified as one of the following:

  • A URL to a feature service layer
  • A feature collection

Examples:

  • "inPourPointData":{"url": <feature service layer url>}
  • "inPourPointData":{"layerDefinition": {}, "featureSet": {}}

outputName

(Required)

The output image service name that will be created.

Syntax: A JSON object describes the name of the output or the output raster.

You can specify the name, or you can create an empty service using Portal Admin Sharing API and use the return JSON object as input to this parameter.

Output name example:

"outputName":{"serviceProperties":{"name":"testrasteranalysis"}}

Output raster examples:

"outputName":{"itemId": <portal item id>}
"outputName":{"url": <image service url}
"outputName":{"serviceProperties":
                  {"name":"testrasteranalysis",
                   "serviceUrl":"http://<server name>/server/rest/services/Hosted/testrasteranalysis/ImageServer"},
                   "itemProperties":{"itemId":"8cfbd3ec25584d0d8f4ed23b8ff7c43b","folderId":"sdfwerfbd3ec25584d0d8f4"}}

pourPointField

The field used to assign values to the pour point locations.

If the input pour point dataset is a raster, use Value. If it is feature, use a numeric field. If the field contains floating-point values, they will be truncated into integers.

Syntax: A string that represents a field name.

Example:

  • "pourPointField": "pptID"

context

Contains additional settings that affect task execution.

This task has the following settings:

  • Extent (extent)—A bounding box that defines the analysis area.
  • Output Spatial Reference (outSR)—The output raster will be projected into the output spatial reference.
  • Snap Raster (snapRaster)—The output raster will have its cells aligned with the specified snap raster.
  • Cell Size (cellSize)—The output raster will have the resolution specified by cell size.
  • Mask (mask)—Only cells that fall within the analysis mask will be considered in the operation.

f

The response format. The default response format is html.

Values: html | json

Response

When you submit a request, the task assigns a unique job ID for the transaction.

Syntax:

{
"jobId": "<unique job identifier>",
"jobStatus": "<job status>"
}

After the initial request is submitted, you can use the jobId to periodically check the status of the job and messages as described in Checking job status. Once the job has successfully completed, you use the jobId to retrieve the results. To track the status, you can make a request of the following form:

https://<raster analysis url>/Watershed/jobs/<jobId>

Accessing results

When the status of the job request is esriJobSucceeded, you can access the results of the analysis by making a request of the following form:

https://<raster analysis url>/jobs/<jobId>/results/outputRaster?token=<your token>&f=json

ParameterDescription

outputRaster

This is the output watershed raster item ID and URL.

Example:

{"url": 
"https://<raster analysis url>/Watershed/jobs/<jobId>/results/outputRaster"}

The result has properties for parameter name, data type, and value. The content of value is always the itemid of the output raster dataset and the image service URL. For example:

{
    "paramName": "outRaster",
    "dataType": "GPString",
    "value": {
        "itemId": "f121390b85ef419790479fc75b493efd", 
        "url": "https://<server name>/arcgis/rest/services/Hosted/<service name>/ImageServer"
    }
}