Modeling Note: Calibrating to Volume
Repeated cross sections are the most common and –often - the most reliable calibration data. Repeated cross sections can be converted to volume change by multiplying the area change by the control volume reach length, or can be summed from upstream to downstream to compare Longitudinal Cumulative Volume Change Curves (See later) HEC-RAS produces. Therefore, while mass change can be more intuitive, volume change is often easier to compare to common calibration data.