October 2017 RiverPro and RioPro ADCP Guide
Page 36
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Stationary Discharge Measurement
A stationary discharge measurement is made by collecting RiverPro/RioPro data with the SxS Pro soft-
ware while keeping the RiverPro/RioPro stationary at multiple locations across the channel, called verti-
cals. For each location, the Hydrologist must maneuver the RiverPro/RioPro to a suitable position in the
cross-section and hold that position while they collect data, typically for a minimum of 40 seconds. For
each vertical the Hydrologist must enter the distance to the reference point, the RiverPro/RioPro depth,
the water depth source, and a flow correction angle (the angle between the distance measurement line and
the flow direction for that location or between the distance measurement line and the beam 3 orientation
of the RiverPro/RioPro).
Best practice for an SxS discharge measurement is for the discharge associated with each vertical to not
exceed 5% of the total discharge for the measurement for a minimum of 20 verticals in a measurement;
but in narrow channels a minimum practical spacing of 10-20 cm between verticals is typically used. A
minimum of two (2) good water profile bins above the sidelobe cutoff are desired at each vertical to enable
extrapolation of flow in the unmeasured top and bottom regions of the profile. After collecting data at
each vertical, the technician will review the results for that vertical with the options of accepting or reject-
ing the collected data, or in some cases extending the data collection interval. Primary indicators of high
RiverPro/RioPro data quality for a vertical are minimum number of bad ensembles, successful measure-
ment of depth, low velocity coefficient of variation and flow direction standard deviation in the data for
that vertical, and consistency with data collected at adjacent verticals. Successful bottom track velocity
measurement may also be required, depending on the SxS Pro processing settings.
Once data has been collected at all desired verticals in the cross-section, the Hydrologist will enter the dis-
tance from the reference point to the end bank of the channel and perform a QA/QC review of the data.
Primary indicators of high RiverPro/RioPro data quality for the overall measurement are small distances
from the banks to the adjacent verticals, consistency of the water velocity profile data between bins (verti-
cally) and verticals (horizontally), and a low overall uncertainty for the measurement.
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