Both the apparent bedload velocity and the backscattering strength measured by acoustic Doppler current profilers could assist bedload assessment in the field. To test this hypothesis, two ADCPs working at three frequencies (3 MHz and 1 MHz, M9; 2 MHz, StreamPro) were deployed simultaneously to measure seven different bedload transport conditions in a laboratory flume. The bedload transport was monitored by two high-speed cameras and a bedload trap. For some experiments 3 MHz and 1 MHz delivered spatially averaged apparent velocity, for others the velocity corresponded to the average velocity of particles. The 2 MHz severely underestimated the average particle velocity. The M9 backscattering strength decreased as the bedload concentration increased, independently of the size and velocity of transported particles. The 2 MHz resulted in almost constant backscattering strength. These findings demonstrate that further examination of the acoustic configurations and parameters could lead to a methodology for bedload quantification based solely on the acoustic outputs.

由声学多普勒电流剖面仪测量的表观床载速度和反向散射强度都可以帮助现场评估床载。为了验证这一假设，同时部署了在三个频率（3 MHz 和 1 MHz，M9；2 MHz，StreamPro）下工作的两个 ADCP，以在实验室水槽中测量七种不同的床载运输条件。两台高速摄像机和一个床单陷阱监测了床单运输。对于一些实验，3 MHz 和 1 MHz 提供空间平均表观速度，对于其他实验，速度对应于粒子的平均速度。2 MHz 严重低估了平均粒子速度。M9 后向散射强度随着床负荷浓度的增加而降低，与输送颗粒的大小和速度无关。2 MHz 导致几乎恒定的反向散射强度。这些发现表明，对声学配置和参数的进一步检查可能会导致仅基于声学输出的床载量化方法。