The information below describes the workflow for setting up pre and postdeveloped scenarios for multiple return events.
1) Choose "yes" when asked if you'd like to create pre/post scenarios upon creating the model, or select this tool from the "new" button in the scenario manager.
2) Enter labels for pre/post scenarios and list the return events to be analyzed.
3) After the scenarios and alternatives are generated, go to Components > Storm Data and either create or import your storm events.
4) Go to Components > Global Storm Data and select the storm events corresponding to each return event.
5) Select one of your predeveloped scenarios as the active/current scenario and lay out or import the predeveloped conditions (for example, a catchment going to an outfall.)
6) Select one of your postdeveloped scenarios as active/current and lay out the postdeveloped conditions. The elements you lay out while in the postdeveloped scenario will be inactive in the predoeveloped scenarios.
7) If the elements from the predeveloped scenarios are different in the postdeveloped scenario, make the necessary changes. For example, if the Tc is different, make the change while in your postdeveloped scenario - the predeveloped Tc will remain intact for the predeveloped scenarios.
If an element from the predeveloped conditions should be gone in the postdeveloped conditions, make the element inactive using the "is active?" property or the Active Topology Selection tool under the Tools menu. For example, if you have a catchment called "pre conditions" in the predeveloped scenario, but that catchment has a different shape in the postdeveloped conditions and should be named "post conditions", then make the "pre conditions" catchment inactive in the postdeveloped scenario, then lay out and configure the "post conditions" catchment.
Since the default active topology setting is Inactive and since the predeveloped scenarios use a different active topology alternative, the "post conditions" catchment will be inactive in the predeveloped scenario and thus not considered in the calculations.
What's new in PondPack V8i