Creating a Model

Because RiverSim's graphic user interface makes it easy and fast to change features and settings in a model, you might be led to believe that there is really not much to creating a new system model. This is not true. Building a good model still requires the same degree of care, experience with the system and good judgment as any other computer model. The advantage to RiverSim is that it makes the mechanics relatively painless and relieves you from the necessity to learn a great deal of computer lore.

To build a new model proceed as follows:
  1. Identify the parts of the river basin you wish to include in your model. Deciding what is "in" and what is "out" is extremely important.

  2. Gather data about the physical characteristics and operating policies of your system. This would include such things as:

    • The location of major structures (reservoirs, channels, diversions, etc.),

    • The physical and hydraulic characteristics of those structures (area capacity tables, head-discharge tables or equations, weir rating curves, heights of dams, etc.),

    • Sources of unregulated inflow,

    • Reservoir storage zones or storage guide curves,

    • Physical or policy constraints on storage or release from reservoirs.

  3. Set default system parameters.
  4. Create objects in the simulation window which represent the structures in your basin.

  5. Link the objects together so that they schematically match the topology of your basin. Here, the links should schematically represent the hydraulic connections between the objects.

  6. Load the physical and policy parameters into the objects.

  7. Add any tables necessary to hold intermediate variables, feed data into the water objects or to collect output from them during the simulation.

  8. Set up any reports that you want the model to produce.

  9. Set the initial conditions.

  10. Load the time series data.

  11. Save the model. If there is a problem with the first version of the model, it will be important to be able to reload it and make adjustments.

  12. Run the model.

  13. Validate, verify and calibrate the model. This is an iterative process of adjusting parameters and policies so that the model behaves as desired.

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Copyright Jon Behrens & Associates, Inc. 1994 - 2000
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