Understanding water quality calibration

The InfoWater Pro Water Quality (WQ) Calibrator provides a fully automated approach to accurate and efficient pipe network calibration, based on water quality.

Goal when calibrating a hydraulic network model using water quality parameters:

To determine the best set of pipe wall coefficients producing the lowest overall deviation between numerically simulated model results and observed field data at specified locations in the system.

Observed field data consists of chemical or other constituent concentration measurements.

Starting a WQ Calibration:

Prior to performing WQ calibration, need to run simulation using Chemical/Temp Water Quality simulation option.

The Run Manager and the Simulation Options dialog box side-by-side, with options configured to run a simulation using the Chemical/Temp Water Quality option and a reminder to use the proper simulation options.

Then, WQ Calibrator can be accessed through InfoWater Pro App Manager to:

Specify data parameters for pipe wall coefficients and junction concentration
Set calibration options
Run calibration simulation
View simulation results
Export changes to model based on results, or use results for further comparison and investigation

Pipe Wall Coefficient Group Tab:

Use to:

Define pipe groups to be used in calibration analysis
Modify any pipe group previously identified
Input ranges of acceptable pipe wall coefficients for each pipe group
Assign a level for each pipe group
Color-code each pipe group

In the Calibrator app, the Pipe Wall Coefficient Group tab, with columns of information on pipe groups to be used in the calibration analysis.

Junction Concentration Tab:

Use to input field measurements for constituent concentration and sample time for selected junctions to be used in WQ calibration analysis.

In two images side-by-side, the Calibrator app, Junction Concentration tab, with columns of information for each Junction ID; and to the right, a comparison graph of observed and simulated junction concentrations of chlorine in mg/L over a 24-hour period.

Before Running a WQ Calibration Simulation:

Can specify optimization properties and simulation options.

Select Run > Options.

The menu area of the Calibrator app, with the Run menu expanded, and Options selected and highlighted in red

In the WQ Calibration Options dialog box, set key run setting thresholds and termination criteria.

The WQ Calibration Options dialog box, with thresholds, termination criteria, and other options configured for a calibration simulation.

The solution refinement process terminates when one of four termination criteria is satisfied.

Advanced genetic algorithm (GA) options are also available—usually these settings do not need to be changed.

Read more in Autodesk InfoWater Pro Help topic, Calibration Options - Advanced Genetic Algorithm (GA) Options.

Under Convergence Method, choose one of three fitness equations—Type #2 is typical for WQ Calibrator simulation.

Running the WQ Calibration:

Select Run > Start.

Use Run tab to monitor progress and performance of simulation.

Once complete, select Run Summary tab to review output results, and review output values on tabs where data parameters were specified.

Switch to Junction Concentration tab to graph correlation between observed and simulated junction concentrations.

A comparison graph of observed and simulated junction concentrations of Chlorine in mg/L over a 24-hour period, with the observed concentrations marked as red triangles and the simulated as a green dotted line.

If satisfied with WQ calibration simulation, use Export tab to export new pipe wall coefficients back into model.