GeoHECRAS can perform an analysis on multiple scenarios at the same time. This is useful, for example, when comparisons of an existing bridge and a proposed replacement bridge are to be analyzed. One scenario could consist of the flow data and another of the geometry data. Computations on the multiple plans can then be performed sequentially (one immediately after the other) using the Multiple Scenarios command contained within the Compute Steady menu item of the Analysis ribbon menu. (A similar command exists for unsteady flow scenarios.)
Selecting the Multiple Scenarios command causes the Compute Steady – Multiple Scenarios dialog box to be displayed.
This dialog box allows the user to select which scenarios to be computed, the flow regime to be used in the computation, and which scenario result file should be loaded by default when displaying the output results. Clicking the [Compute] button will cause HEC‑RAS to perform the multiple scenario analysis.
Displaying Multiple Scenario Results
After the computations have been performed, the software can display the results from multiple scenarios overlaid on each other for the following output results:
- Cross Section Plot
- Profile Plot
- General Profile Plot
- Rating Curve
- Stage & Flow Hydrographs
- Summary Output
To view the output results, select the Results ribbon menu and choose the output menu command. For example, select the Profile Plots command from the Results ribbon menu.
The Profile Plot window will be displayed. From the Profile Plot window, select Plans from the Options menu. The Plan Selection dialog box will be displayed and the user can then select the scenarios (or plans) to display.