Menu:  Run Calibrate

This procedures should be applied only be experienced users with adequate site-specific monitoring data.

The model must be executed successfully (Run Model) before attempting calibration.  Be sure to save the model input file before running the calibration, so that it can be restored if the calibration is unsuccessful.  See discussion of calibration concepts .

This procedure derives least-squares estimates for model calibration factors , calculated from log-transformed observed and predicted concentrations of conservative substance, phosphorus, nitrogen, and/or chlorophyll-a in each model segment.

Calibrating to conservative substance data (e.g., chloride) involves adjusting the longitudinal dispersion rates (vs. sedimentation rates for nutrients).

Calibration parameters are defined by the following user inputs on the calibration screen:

• Select Variables.   Choose one or more observed variables to be calibrated.  The variable will not be available if there are no observed values.  The calibration will occur in sequence.
• Select Calibration Type.
    Global     -      calibrate factors that apply to all segments (as specified on the Edit Model Coefficients screen)
    Regional  -      calibrate factors that apply to each segment ( Edit Segments screen) with uniform values within each segment group
    By Segment -  calibrate factors that apply to each segment separately
• Select Segments.    Select segments to be considered in a regional or segment calibration.  Has no effect on a global calibration.
• Calibration Factors Apply to.  Sedimentation rates or predicted concentrations.  This refers only to phosphorus and nitrogen. 

Buttons at the top of the screen provide the following functions:

Run          Run the Calibration for each specified variable in sequence. A window at the bottom of the screen displays intermediate results. 

Reset       Reset the selected calibration factors t their default value (1.0)

Reset All   Reset calibration factors for all variables and segments to 1.0

List          List final results (calibration results & goodness of fit statistics)

Help         Display this screen

Quit         Return to Program Menu