Each alternative represents the combination of a reservoir network, a selection of one operation set per reservoir, the specification of the initial conditions of each reservoir, and the selection of inflows and other input time-series datasets needed by your model. An Alternative consists of a Reservoir Network (previously created from a Configuration), Run Control specifications, an Operation Set for each Reservoir in the network, a Storage Balance Operation Set for each Reservoir System in the network (if applicable), a definition of initial (Lookback) conditions, and a mapping of all Time-Series records to identified local inflows. To develop an Alternative, you use the Alternative Editor to name the Alternative and give it a description, define the Time Step and Flow Computation method, select Reservoir Operation Sets, select System Operation Sets (if applicable), select a Lookback Type, associate time-series data with locations, associate observed data with locations, and save the Alternative you have created. This chapter will guide you through these steps.

Updates to the Alternative Editor in ResSim 3.5

Accessing the Alternative Editor

To access the Alternative Editor ("Figure: Alternative Editor"), choose Edit from the Alternative menu in the Reservoir Network Module.

Figure: Alternative Editor

Creating An Alternative

The first step in creating an Alternative is to give it a Name and Description, and then select the reservoir Network you want to use.

To create a New Alternative:

  • From the Alternative menu of the Alternative Editor, select New. The New Alternative dialog will open ("Figure: New Alternative").

    Figure: New Alternative

  • Enter a Name and Description. Use the button to open a larger editing window for the description.
  • Select a Network by choosing from the list of available networks.
  • Click OK to close the New Alternative dialog. The name and description you entered will now appear in the Name and Description fields of the Alternative Editor ("Figure: Alternative Editor - Name and Description Fields").

    Figure: Alternative Editor - Name and Description Fields

Settings on Alternative Editor Tabs

Alternative Editor TabsTab NamePurpose/Notes

Primary tabs

These tabs are mandatory to set up any alternative for simulation with ResSim.

Run Controlsetting control specs such as the alternative type, time step, etc.
Operationsselection of operating sets, storage balance sets, and water account sets
Lookbacksetting initial conditions
Time-Seriesidentifying input time series

Secondary tabs

These tabs are optional for setting up a standard ResSim alternative for simulation.

Observed Dataidentifying observed data time series
DSS Outputdialing down the writing of output time series
Hotstart

using results from a previous run to set the initial conditions

(tab only available when "Enable Hotstart" is selected on the Run Control tab)

Special Alternative Type tabs

Each of these tabs only become available when that is the selected Alternative Type.

Yield Analysistab only available when alternative is of type Yield Analysis
Ensembletab only available when alternative is of type Ensemble
Monte Carlotab only available when alternative is of type Monte Carlo

The following subpages walk through setting up all but the special alternative type tabs.

Saving an Alternative

When you have finished defining an alternative, save it by selecting Save from the Alternative menu of the Alternative Editor, as shown in "Figure: Reservoir Network Module - Network Menu - Save Network".

Figure: Reservoir Network Module - Network Menu - Save Network

You may then close the Alternative Editor. It is a good idea to save your Network and Watershed after creating a new Alternative. To do this, select Save from the Network menu "Figure: Reservoir Network Module - Network Menu - Save Network", and then select Save Watershed from the File menu ("Figure: File Menu - Save Watershed").

Figure: File Menu - Save Watershed