Developing Model Alternatives

A model alternative is a single configuration with a specific set of input and parameters. A second model alternative would be defined by a different configuration, different input, or different parameters. Since model alternatives do not include time-specific data, you can use a model alternative with any time window.

Initially, you develop alternatives using the software of the native model (e.g., HEC-HMS, HEC-ResSim, HEC-RAS, and HEC-FIA). Then, you import these alternatives into HEC-RTS. Once the model alternatives have been imported, from the Setup module you can configure and edit specific model alternatives for use in HEC-RTS.

For example, since MFP deals with future precipitation, you can configure model alternatives to use in conjunction with HEC-HMS to compute a variety of future precipitation scenarios. Since HEC-HMS simulates watershed response to precipitation, then you can use HEC-HMS alternatives to forecast future flows. These future flows can be used with the reservoir software application HEC-ResSim, to compute reservoir releases. Regulated flows and stages from HEC-ResSim can be input to HEC-RAS and HEC-FIA model alternatives. Basically, all individual model alternatives created in the native programs are available to HEC-RTS.

In the Setup module, you will create model alternative keys that will be used in creating a forecast run. Each key is a single alpha-numeric identifier that represents a model alternative. For example, the Key N might represent normal conditions, the Key W might represent wet conditions, and the Key D might represent dry conditions. Refer to Model Alternatives and Forecast Runs for additional information on model alternatives.