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Calibration Display

The calibration display forms a special part of the forecasting systems that allow automatic calibration of any model connected to FEWS through the General Adapter. The model to calibrate must have a correctly configured General Adapter module Instance and included in a workflow. The calibration display (or utility) will be available only in the stand alone system, as it is not considered a functional part of an on-line system.

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• Model to Calibrate
• Model Parameters
• Run Options
• Results
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Model to Calibrate

In the first tab the user must enter all information concerning the model to calibrate. Not all models can be selected, the requirements for a calibration model run are:

• The model must allow module parameters to be exchanged through the Published Interface Exchange XML format.
• For each model the Parameter Files must be added to the ModuleParFiles configuration directory.

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Once the selection has been entered in the Model Calibration tab it can be stored to a file by pressing the \[Save\] button. Next time the calibration utility is used the \[Load\] button can be used to load the selection.
1.2 <ac:structured-macro ac:name="anchor" ac:schema-version="1" ac:macro-id="f6e898e2-e9fa-4563-8b78-a6a17bdbd727"><ac:parameter ac:name="">_Toc172823895</ac:parameter></ac:structured-macro><ac:structured-macro ac:name="anchor" ac:schema-version="1" ac:macro-id="a2c19130-6986-400e-8bf6-454abf6ae93a"><ac:parameter ac:name="">_Toc140564202</ac:parameter></ac:structured-macro>Model Parameters 
The Model Parameters tab includes a spreadsheet with all model parameters that can be adjusted by the calibration 

Model Parameters

The Model Parameters tab includes a spreadsheet with all model parameters that can be adjusted by the calibration utility.

The parameters shown in the spreadsheet are the model parameters of the parameter file that is selected in the upper drop down list. Once the spreadsheet has been filled with parameter values the model parameters can be selected that need to be optimised through the calibration utility. A model parameter can be selected by checking the "Adjust" column in the spreadsheet. Make sure that the original, minimum and maximum values for the selected parameter have realistic values. 1.3 Anchor_Toc172823896_Toc172823896 Anchor_Toc140564203_Toc140564203

Run Options tab

In the Run Options tab the final set of definitions must be set that allows the method and constraints of calibration to be defined. These include:

1. The calibration method to be used- thus may either be the Local gradient method "SuperDUD" or the global "SCE-UA" method. At the moment only the SuperDUD method is implemented.
2. The performance indicator to be used in calibration. The enumeration of this is "BIAS", "MAE", "MSE", "NS", "PEAK_MSE" and "PERCENT_VOLUME".
3. A number of termination criteria. All are available and may be selected for application or not considered:
a) Maximum number of runs.
b) Threshold change in performance
c) Threshold change in parameter vector

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Results

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1.4 <ac:structured-macro ac:name="anchor" ac:schema-version="1" ac:macro-id="bd3951d3-8872-4057-8491-46e092298cfc"><ac:parameter ac:name="">_Toc172823897</ac:parameter></ac:structured-macro><ac:structured-macro ac:name="anchor" ac:schema-version="1" ac:macro-id="0c6f7518-8c50-4389-88ef-116a88751382"><ac:parameter ac:name="">_Toc140564204</ac:parameter></ac:structured-macro>Results 
The results tab shows the calibration results in a graph. To start the calibration utility the \[Run\] button must be pressed. The workflow will be started and the model parameters adjusted by the calibration utility. The user can follow the calibration progress by analysing the graph and the current iteration and current performance values located in the progress info frame.

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By pressing \[Close\] the Calibration display can be closed.
1.5 <ac:structured-macro ac:name="anchor" ac:schema-version="1" ac:macro-id="3e88b69a-62c1-4a48-a2e2-23ca792cdbaa"><ac:parameter ac:name="">_Toc172823898</ac:parameter></ac:structured-macro><ac:structured-macro ac:name="anchor" ac:schema-version="1" ac:macro-id="38f0004d-8910-4503-ba67-53ca978be744"><ac:parameter ac:name="">_Toc140564205</ac:parameter></ac:structured-macro>Working efficiently with calibration 
When working with the calibration utility a complete workflow must be run in order to optimise one of the modules in that workflow. In the calibration process this workflow will be run for multiple iterations. When the module is included in a fluvial workflow for the complete region each iteration will require a long time to complete. It is therefore recommended to create specific "calibration" workflows that only include one or several modules; the number of modules not contributing to the calibration module must be minimised. This will bring down the calculation time considerably. Especially for rainfall-runoff modules it will not take much time to create such calibration workflows.

Working efficiently with calibration

When working with the calibration utility a complete workflow must be run in order to optimise one of the modules in that workflow. In the calibration process this workflow will be run for multiple iterations. When the module is included in a fluvial workflow for the complete region each iteration will require a long time to complete. It is therefore recommended to create specific "calibration" workflows that only include one or several modules; the number of modules not contributing to the calibration module must be minimised. This will bring down the calculation time considerably. Especially for rainfall-runoff modules it will not take much time to create such calibration workflows.

1.6 When running the calibration utility a database must be used with a complete set of historical data. Such a database can be created using the on-line or off-line systems or by importing data from HARP.