If you only use customer consumption to calibrate the hydraulic model, what can happen in the calibration?
If you assume that all of the discrepancies between the model and the field data are due to customer consumption, you may miss serious errors in data collection, pipe roughness, connectivity,... The key to calibration is determining WHY the model and field data differ and fixing that issue.
Sometimes you may improve calibration for a single data set by adjusting the wrong parameter but this will give you a worse model and it will show up in other data sets. This is what I call "Calibration by compensating errors."
Here is a list of some of the reasons that calibration might need additional work. How confident are you that all of teh discrepancies are due to consumption?
Physical
Pipe size/location
Pipe connectivity
Pipe roughness
Pressure zone boundary
Pump curves
Pipe material/age in GIS
System changes since model built
Elevation data
Operational
Valve open/closed/throttled status
Control valve operation/settings
Transient events
Actual operations not matching control rules
Unusual operations when data were collected
Tank water levels
Pump status/speed
Lack of sufficient sensors/gages
Water quality reaction rates
Demands
Spatial allocation
Model does not reflect conditions when data collected
Large customers with atypical demand patterns
Not accounting for seasonal changes in demand
Data
Inaccurate/uncalibrated gages/meters
“Latched” data from SCADA
Understanding SCADA data – average vs. instantaneous
If you use the flow provided together with the consumption of the customers' meters, will the model understand that the difference could be water losses?
With the leak detection feature in the Darwin Calibrator tool in WaterGEMS, you can specify measured/observed flow and pressure and the tool will take that information along with the model network and entered demands (whether they are from customer meters or directly on junctions) and will attempt to determine the location of leaks by trying emitter coefficients (pressure dependent demands) at various locations until the model results closely match the observed/measured values. See more here:
Performing Leakage Detection Using Darwin Calibrator
Tips for Water Loss Management and Leak Detection
Water Model Calibration Tips
Regards,
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.