After creating a forecast run, you need to link the model alternatives so each model receives the necessary input data - either from the Extract List or from other models within the forecast. This is accomplished using the Model Linking Editor. 

This guide will walk you through how to access the Model Linking Editor and configure the data connections to ensure your models have the inputs they need to compute successfully.

Accessing the Model Linking Editor

There are two ways to access the Model Linking Editor, depending on the data you want to edit:

  • Setup tab - Use this to edit model linking for the Base Forecast Run.
  • Modeling tab - Use this to edit model linking for the Active Forecast's Model Alternatives. 

From the Setup Tab

  1. Launch HEC-RTS and open your watershed.
  2. Navigate to the Setup tab.
  3. From the Models menu, select Model Linking.

From the Modeling Tab

  1. Launch HEC-RTS and open your watershed.
  2. Navigate to the Modeling tab.
  3. Create a new forecast or open an existing one.
  4. From the Forecast tab, select Model Linking.

Editing Inputs using the Model Linking Editor

The Model Linking Editor works the same regardless of how you access it.

  1. In the Model Linking Editor, select the forecast run you want to configure from the Forecast Run dropdown.
  2. From the Model Requiring Input dropdown, choose the model alternative to edit. In the example below, the MetVue-NexradQPF model alternative for the metvue-summer-realtime-unsteady forecast run is selected. 
  3. In the editor table, set the Input From for each row by choosing either a model alternative or the Extract List.

  4. For rows where Input From is a model alternative, specify the correct Location/Parameter.
    1. HEC-RTS tried to match these automatically, but review each and make corrections as needed using the dropdown.
  5. Repeat steps 2 through 4 for each model alternative in the Model Requiring Input dropdown.
  6. Click Apply to save your changes, then OK to close the dialog.

Additional Features of the Editor

There are several features included in the Model Linking Editor that may help you as you review and update linkages.

Model I/O

Click Model I/O to view the inputs and outputs for each model alternative.

Select Input Model Alternative

This tool lets you set a single input source for all rows not currently linked to the desired input. 

  1. Click the Select Input Model Alternative button.
  2. Choose a model alternative or the Extract List from the dropdown, then click OK.
  3. When prompted, click Yes to apply this input to all unlinked rows.

You can also use this tool to set the input source for a subset of the rows in the table.

  1. Select the desired rows in the table.
  2. Click the Select Input Model Alternative button.
  3. Choose a model alternative or the Extract List from the dropdown, then click OK.
  4. When prompted, click Yes to apply this input to all selected rows.

Get Linkages From

Use this tool to import model linkages from existing model linkages or another forecast run.

  1. Click Get Linkages from.
  2. In the Select Model Linkages to Use dialog, choose:
    1. Use Existing Linkages 
    2. Use Linkages from a Forecast Run 
      1. Select the appropriate forecast run from the list. 
  3. Click OK to apply your selection and close the dialog.

Save Linkages to Model

This tool allows you to save linkages to model-specific files (e.g., a .dsv file in the HEC-HMS project directory).

  1. Update model linkages as needed within the dialog.
  2. Click Save Linkages to Model.
  3. Click Yes to confirm.

Note: Clicking Apply or OK in the Model Linking Editor saves the linkages to a file located in the cavi/modelLinking folder in the watershed directory.

Final Review

Once your updates are complete:

  • If you edited linkages from the Setup tab, create a new forecast.
  • If you edited from the Modeling tab, run the active forecast.

Verify that the forecast runs without errors and that models are receiving the correct input data. If needed, make adjustments and rerun the forecast until it computes successfully.