Development of a system to measure bed forms and vertical velocity profiles in a river channel

摘要

A new observation system using acoustic Doppler current profiler (aDcp) and Multibeam Echo Sounders (MBES) were proposed to discuss flow resistance in relation to water flow, sediment transport and bed forms. The system was tested for its validity based on bed forms and velocity profiles, which were measured in a quasi-actual scale experiment flume with a movable bed. The system is applicable to the measurement of the channel flow and behavior of an erodible bed. Measured data found 1) the best combination of bedload discharge equation and method for estimating friction velocity, 2) the estimation method for friction velocity is also effective method to evaluate the relationship between dimensionless shear stress and bed forms. The equation is proposed by Egashira et al (1990, 1997). The estimation method is proposed by Yorozuya et al (2010).