Available with ArcGIS Image for ArcGIS Online.
The Watershed tool determines the contributing area above a set of cells in a raster.
The output is a hosted imagery layer.
Given an input point on the Mississippi River in Louisiana, you can use the tool to identify the contributing area above the point. The contributing area, or watershed, will extend to include areas from New York to Montana and into Canada.
Watershed includes configurations for input layers and result layers.
The Input layers group includes the following parameters:
Input flow direction raster defines the direction of flow out of each cell.
The flow direction must have been determined by the D8 method.
Input pour point raster or features defines the locations above which the contributing area will be determined.
This input can be a raster or point feature.
In the case of a raster, each cell with a valid value will be considered a location.
In the case of a point feature layer, each point will be considered a location and the default field will be the first available valid field.
If no other valid fields exist, the ObjectID field (for example, OID or FID) will be the default.
Pour point field is the field used to assign values to the pour point locations.
If a raster was specified for the Input pour point raster or features parameter, the Value field is used by default. This field corresponds to the cell values in the raster. Each cell value will be used to assign a value to the identified watershed given the cell.
If a feature layer was specified for the Input pour point raster or features parameter, any numeric field can be used. If the field contains floating-point values, they will be truncated into integers. By default, the first available valid field will be used. If no valid fields exist, the ObjectID field (for example, OID or FID) will be the default.
The Result layer group includes the following parameters:
Output raster name is the name of the raster that contains the watershed areas differentiated by the pixel value derived from the Pour point field parameter.
The name must be unique. If a layer with the same name already exists in your organization, the tool will fail and you will be prompted to use a different name.
- Output layer type specifies the type of raster output that will be created. The output can be either a tiled imagery layer or a dynamic imagery layer.
- Save in folder specifies the name of a folder in My Content where the result will be saved.
The following limitations apply to the tool:
- The Watershed tool only supports a D8 input flow direction raster layer.
Analysis environment settings are additional parameters that affect a tool's results. You can access the tool's analysis environment settings from the Environment settings parameter group.
This tool honors the following analysis environments:
This tool consumes credits.
Use Estimate credits to calculate the number of credits that will be required to run the tool. For more information, see Understand credits for spatial analysis.
This tool includes the following outputs:
- One output raster with the watersheds identified at each given location. It is an integer raster.
This tool requires the following licensing and configurations:
- Creator or GIS Professional user type
- Publisher, Facilitator, or Administrator role, or an equivalent custom role
- ArcGIS Image for ArcGIS Online
Use the following resources to learn more: