Model Building Steps
Following is a very general description of the steps involved in building a simulation model. These steps should be performed in order with the exception of Step 5., and Step 6. which are interchangeable. Each step is discussed in greater detail below.
1. Set the model timestep size and the start/end dates in the Run Control dialog.
2. Set the Number of Post-Run Dispatch Timesteps.
3. Create a Unit Scheme
4. Add objects to the workspace from the palette.
5. Select the appropriate methods on each object.
6. Link the objects together.
7. Input the required data.
8. Run the model and evaluate the output.
See Selecting the Controller and Setting Run Times in Building a Model for details.
Set Timestep and Start Date
Before adding objects to the workspace, the user should select the model timestep and specify the start and end dates of the run. This is done through the Run Control dialog.
Set Number of Post-run Dispatch Timesteps
Set the number of timestep after the run for which dispatching should be allowed. Typically you can set this equal to the forecast period. See Post-run Dispatching for instructions.
Define Display Units Through a Unit Scheme
The first step when setting up a model is specifying the display units for objects taken from the palette. The internal units in RiverWare are SI units but you can define the display units, scale, precision and format by setting up a Unit Scheme. In the Unit Scheme you configure these four attributes for each unit type. Then you can define exceptions to the general rule. That is, for a specific slot you may want to show the values in some other display unit. See Unit Schemes in User Interface for details.
Add Objects to the Workspace
Build the model network with appropriate selection of objects from the RiverWare object palette. Include control point objects at the desired locations.
Select Methods on Objects
On each object, select methods to model various physical processes (i.e. spill, evaporation, seepage, routing, etc.) depending on the level of modeling detail required. See Reservoir Objects for details on these methods for the basic simulation model.
Note: These methods are strictly for the calibration model; additional methods will be selected later to implement the flood control, surcharge, and conservation pool operations.
Link Slots
Slots on objects should be linked to form the network representing the basin. For example, Reservoir Outflow should be linked to the downstream control point or reach’s Inflow slot.
Input Data
Supply the required data to the objects. There are two types of data, table or parameter data and mass balance data.
• Table/Scalar data. Specify required table/scalar data to the slots on the objects.
• Mass Balance and series data. The user should specify unregulated local inflows to control point and reservoir objects; see Forecasting Incremental Local Inflows From Cumulative Flows. In addition, specify enough mass balance data, typically on the reservoir objects, to run the model. This could include inflows and reservoir storage, pool elevations, or outflows; see Reservoir Inflow and Mass Balance Data.
Run and View
Once all objects have been configured (method selection and input data) and have been linked together, the model is ready for simulation. When the model is run, it should compute the inflow forecasts, mass balance the reservoir objects, and properly route releases downstream. The purpose of these simulations is to ensure that the modeling of the physical system has been done correctly. During this stage the model should be calibrated if necessary. Any error messages or data problems need to be resolved before moving to policy modeling. Since the inflows, uncontrolled area flows, and storage or pool elevation values have been input, each reservoir should mass balance correctly to solve for outflow. These outflows should also be routed downstream. The modeler can also input reservoir outflows and check the resulting storages and pool elevations. The resulting values computed by RiverWare should be checked against known values for accuracy. See Modeling Unregulated Conditions for details on viewing and analyzing results.
Revised: 12/06/2024