Watershed Segmentation

Watershed Segmentation is the process of dividing a watershed into several sub-watersheds. Larger watersheds can be obtained through Calculate Watershed Basin, but in actual analysis, the larger watersheds may need to be divided into smaller watersheds (called sub-watersheds).

Instructions for use

The first step in determining the watershed is to determine the catchment point of the watershed, so Watershed Segmentation also first determines the catchment point of the sub-watershed. Unlike Calculate Watershed Basin, the catchment points of a subwatershed can be on the boundary of the grid or inside the grid. Therefore, the catchment data of Watershed Segmentation can be either the Raster Data obtained from the previous Calculate Watershed Point, or the two-dimensional point set representing the catchment point can be used to segment the watershed.

Function entrance

  • Spatial Analysis tab-> Raster Analysis group-> Hydrological Analysis-> Watershed Segmentation.
  • Toolbox, Raster Analysis, Hydrological Analysis, Watershed Segmentation.

Parameter Description

  • Flow Direction Data: Select Datasource and Dataset where Direction Raster is located.
  • Pour Point Data: Select Datasource and Dataset where Pour Point Data is located. Pour Point Data can be calculated catchment point Raster Data or Point Dataset collected on the spot.

    Note: Watersheds extracted by Watershed Segmentation correspond to catchment points. If the catchment of some watersheds does not reach the set threshold for extracting catchment points, these catchment areas will not be reflected in the results of Watershed Segmentation. Therefore, the result of Watershed Segmentation may not cover all of the DGM range. If you want the watershed result to cover all of the Analysis Bounds, you can use the Calculate Watershed Basin function.

  • Filter: Valid only for 2D Pour Point Data. Filter Expression can be set to set the catchment point participating in Watershed Segmentation.
  • Result Data: Set the name of the Datasource and Dataset to save the result.
  • Click the Execute button to execute the prepared analysis function. After the execution completed, the Output Window will prompt whether the Result succeeds or fails.