Abstract
In recent years, estimation techniques of suspended sediment concentration using backscatter intensity of ultrasonic wave have been developed. However, sampling method of suspended sediment for accuracy verification has become a technical issue. Flood flow observation was carried out in the Ishikari River by using improved the Van Dorn water sampler. As a result, we succeed water sampling at near river bed, and collected the suspended sediment which has uniform particle size that is different from the bed material. Furthermore, the measured data was applied to the suspended sediment concentration distribution equation considering the wash load, it was possible to reproduce the vertical distribution of measured sediment.
