where_build (11/25/04)

    The Build feature of the CRHM pull down menu allows the user to choose pre-defined models,  build their own model from the available modules and to delete all modules from the current model.

pre-defineded models.

    The pre-defineded models are created by the creator of modules to demonstrate the module application.  Current examples are Evap and PBSM.  To change the number of HRUs or layers from their current values,  the user must use Clear Modules if an existing model is loaded and then change the number of HRUs or layers.

Clear Modules.

    This menu option removes all currently selected modules.  It should be used before defining a new model.  Unless Clear Modules is executed it is not possible to change the number of HRUs or layers from their current values.

Construct.

    The Construct screen allows the user to add or delete modules from the current model and to retrieve more information about a module interface.   Models can be checked and built.

 

Defining Models.

    On the lower right hand corner of the Construct window there are two UpDown controls called MAXLAY and MAXHRU. These allow the user to set the number of HRUs or layers to be used in the model.  These should be set before any modules are added.  To change the dimensions for an existing model it must be rebuilt from scratch after changing the dimensions.  A parameter file from the original model will reload all the parameters correctly if the number of dimensions is the same or reduced.   However, if the number of dimensions is increased the extra dimension of parameters will be set to the values of the last HRU defined.  Any new modules added will have the module default parameter values.

    The Construct window displays on the left hand side a list of all the available modules. When a module is selected a spreadsheet on the right hand side of the screen displays the module interface.  This description includes required inputs, parameters, observations and variables and also the output variables generated by the module.

    By right clicking on a module in the Modules Available box the module will be added or deleted from the model. When assembling a model the last module should be selected and then the Check option selected. CRHM will then determine the supporting modules required and add them to the model by moving them to the Selected listbox.  When a module has wildcard inputs the program can only make suggestions to which modules will satisfy the input requirements.  The user can then add the desired module from the list of suggestions.

    Selecting the Build option box exits the screen making the new model the current model.  If changes are made to an existing model the user will be asked if they wish to save their existing parameters to a *.par or *.dbx file for reloading by the user after the the modified model is built.  N.B. It is preferable to use *.par files as *.dbx files are limited to 10 character parameter names.

    The Cancel option box exits the screen without making any changes to the model.

 

Creating a Model from scratch.

    Run CRHM and do not load any project or modules.

1. Set # of HRUs to the desired value.
2. Load module basin if it is desired to give HRUs text names.
3. Load other modules.
4. Build model - no need to save parameters.
5. Set parameters to desired values.
6. Save model to a project file.

Having observation files open does not affect the build procedures but the file names will be saved with the project.