You may want to run the models individually for calibration before doing a full compute of the forecast run. This is particularly important for HEC-HMS because there are event-dependent parameters (loss rate and baseflow) that you will need to adjust for the forecast. HEC-HMS will produce simulation hydrographs, which you can compare with observed hydrographs up to the time of forecast. These comparisons will determine if you need to adjust your HEC-HMS model.

In the case of HEC-ResSim, you are using the simulated releases as a guide. After reviewing the releases, you might decide that you need to adjust the releases to better simulate actual reservoir operations. For HEC-RAS, you are checking profile information throughout the lookback period; if results are not satisfactory, you can calibrate HEC-RAS by modifying "n-values" at selected cross sections. In the case of HEC-FIA, you might need to adjust the levee failure stages to see the associated damage and impacts during an event.

Each HEC-RTS software application has its own individual editor; these editors are described in detail in Model Alternatives and Forecast Runs. For each HEC-RTS software application, there are only certain parameters that you can edit. If you need to make additional changes beyond those specific parameters, you will have to revise the model alternative using the model's standalone application and re-import the model into your HE-RTS watershed.

In Version 3.1.1, you can edit any of the model data because of the native module interface used. Care should be exercised when editing calibrated models configured in HEC-RTS to prevent models from "breaking".

Computing Individual Model Alternatives

To run a forecast through an individual model:

1. From the Forecast Runs Detail section (Model Alternative - Shortcut Menu) of the Modeling module, right-click on a model alternative of a forecast run. From the shortcut menu, click Compute. Note that the models are computed in the same order as the Program Order you have set up. For example, if you want to compute a forecast run through the HEC-ResSim model alternative, right-click on the HEC-ResSim model alternative.
2. The Compute Progress dialog (Compute Progress Dialog) opens and HEC-RTS begins execution of the HEC-RTS software applications up to the model that you have chosen. For example, if you choose to run through HEC-ResSim, HEC-RTS will compute the MFP, HEC-HMS, and HEC-ResSim model alternatives.

After the completion of the computation, you will need to review reports to help in your calibration. HEC-RTS Results describes in detail the available reports for each individual model.

Editing Individual Model Parameters

After you have made your initial run and reviewed results, you might decide you need to edit parameters for an individual model. From the Forecast Runs Detail section (Model Alternative - Shortcut Menu) of the Modeling module, depending on the model alternative that you have right-click on, the shortcut menu displays a range of editing options (Model Alternative - Shortcut Menu). The editor associated with that forecast run, opens and you can edit the necessary parameters. Each model has its own individual editor, which are described in detail in Model Alternatives and Forecast Runs.