4.5 Article

Pulse Coherent Doppler Profiler Measurement of Bedload Transport

Journal

Publisher

AMER GEOPHYSICAL UNION
DOI: 10.1029/2020JF005572

Keywords

acoustics; bedload transport; coherent Doppler; sediment transport

Funding

  1. Atlantic Canada Opportunities Agency [193499]

Ask authors/readers for more resources

Previous studies show that bottom velocity measurements from Doppler sonar systems can be used to rapidly sample bedload transport processes, but validation and understanding of the sampling mechanism are necessary before full utilization. Experimental results demonstrate agreement between MFDop measurements and measurements based on bedform migration rates and sediment traps in the SAFL flume.
Prior studies demonstrate that bottom velocity measurements from Doppler sonar systems are proportional to bedload transport rates. These observations suggest that acoustically based systems offer a capability for rapid sampling of bedload transport processes. Before these measurements can be fully utilized, validation and understanding of the sampling mechanism are essential. We explore the measurement mechanism through a series of laboratory trials with a field instrument, the multi-frequency coherent Doppler profiler (MFDop). The MFDop system is a multi-frequency (1.2-2.2 MHz), bistatic Doppler sonar that provides three-component ensemble-averaged velocity profiles over a similar to 30 cm depth interval with up to 1 mm resolution at a rate of 50 profiles/sec. Tests of the MFDop system were carried out in the main flume in field-scale conditions at the St. Anthony Falls Laboratory (SAFL) using 1 ms(-1) mean flows over a mobile bed of sand with median grain size d(50) = 0.4 mm. We find agreement between MFDop transport measurements and measurements based on bedform migration rates, and sediment traps built into the SAFL flume. Predictions using the Meyer-Peter and Muller (1948) empirical equation closely match our observations while in contrast, predictions using the Nielsen (1992) equation are a factor of two higher.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.5
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available