An experiments for sediment collision ratio of hydrophoneipipe geophonej

Taro UCHIDA, Nobuya YOSHIMURA, Shin’ichiro HAYASHI, Kenji TSURUTA,
Takuro SUZUKI, Yuji HASEGAWA, Jun’ichi KANBARA and Takahisa MIZUYAMA

The difficulties in directly monitoring bedload have been recognized and prompted research into surrogate monitoring technologies, including acoustic methods and seismic methods. In Japan, in the last decade, hydrophones (pipe geophone) were widely used in mountainous rivers to monitor bedload. Thus, recently, monitoring data has been dramatically increased. It has been widely recognized a part of bedload might not hit pipe due to complex sediment transport processes, likes saltation and so on. Thus, the observed bedload amounts might be underestimated. However, there was no adequate information about the degree of this underestimation. Here we proposed a method for quantifying the ratio of sediment hit hydrophone to total sediments. Then, we confirmed our proposed method using comparison between our estimated value using hydrophone data and high speed video images.