Model Calibration An Overview Victorian Modelling Group Workshop Facilitators: Stephen D’Agata – AECOM Matthew White – City West Water

Introduction Why Bother? ◦D◦D o Models always need to be calibrated? ◦B◦B uilt model represents network as it should be… ◦O◦O r as it appears to be in the GIS ◦N◦N eed models to represent networks as they are. Models are virtual representations of…… REAL SYSTEMS

Introduction What is Calibration? ◦ Getting the model to reproduce observed hydraulic conditions (Virtual representation of real systems) ◦ Need observed data to calibrate to. ◦ Observed data should represent extreme conditions ◦ Model parameters are adjusted until modelled data matches observed data ◦ Can’t calibrate the entire network ◦ Can only calibrate elements of the network

Introduction Water Network Model Calibration: ◦ Observed Pressure Including Tank and Reservoir Levels. ◦ Observed Flows and Pump Operation ◦ Need peak demand conditions to test network hydraulics. ◦ Models generally calibrated to peak summer conditions.

Introduction Sewer Network Model Calibration: ◦ Observed flows (Velocities and Depths) ◦ Observed Pump Operation ◦ Peak flow conditions generally associated with rainfall induced flows ◦ Need to monitor rainfall concurrently with flows ◦ Models need to be calibrated to dry weather first ◦ Then rainfall runoff routing is used to calibrate rainfall contribution

Workshop Outline Data Collection ◦ What, Where, How? ◦ Monitoring Specifications ◦ SCADA Data ◦ Monitoring Contractors ◦ Data Review

Workshop Outline Model Calibration ◦ Calibration Specifications ◦ Event Selection ◦ Proof of Calibration ◦ What if Model Won’t Calibrate

Workshop Outline Wrap Up ◦ Lessons learned ◦ Future Workshops

Data Collection What? Where? How? ◦ What do we measure ◦ Where do you place monitors ◦ How do you arrange monitoring Specifications ◦ Monitoring Tolerances ◦ Capabilities of Modelling Equipment

Data Collection SCADA Data ◦ Operational requirements vs modelling requirements ◦ Accuracy ◦ Calibration of monitors ◦ How is data recorded ◦ Can data be downloaded

Data Collection Contractors ◦ Who is out there ◦ Are they any good Data Review ◦ How do you know you are getting good data ◦ Data checks ◦ Data consistency ◦ Error accumulation

Calibration Specification ◦ Calibration tolerances ◦ Consistency with data accuracy ◦ Reporting requirements Event Selection ◦ Time series vs event based ◦ Peak events

Calibration Proof of Calibration ◦ Calibration plots ◦ Statistical comparison What if Calibration cannot be Achieved? ◦ Data anomalies ◦ System anomalies

Wrap-up What have we learnt from today Future Workshop Topics