Study on non-sampling field meant system of sediment discharge using hydrophone

本研究的目的是开发一种利用水听器来检测泥沙颗粒对水听器的冲击的泥沙流量估计方法。根据农民的研究，已知由于碰撞引起的声音振幅将与移动泥沙的动量成正比。在床载情况下，泥沙颗粒的运动具有统计性质。因此，我们可以确定从碰撞振幅统计到泥沙颗粒数量的转移作用。结果表明：(1)振幅的统计性质在很大程度上取决于泥沙的直径。(2)了解床附近的流速或剪切速度是很重要的。将平面二维电磁测速仪安装在固结坝顶等刚性坝体上，测量坝体附近的速度。(3)知道应用估计方法的极限也是很重要的。该极限可以用无因次剪切应力来计算，其判据取决于地层梯度。在此基础上，建立了考虑河床形态的泥沙运动和排斥力的数值模拟模型，并讨论了确定声信号（振幅）到泥沙流量的传递矩阵的方法。讨论了集水区降雨与泥沙径流过程的综合观测系统。

The aim of this study is to develop an estimating method of sediment discharge using a hydrophone to detect the impacts of sediment particles to the hydrophone According to farmer studies, it is known that the amplitude of the sound due to collisions would be in proportion to momentum of moving sediment In case of bed load, the movement of sediment particles has a statistical property. Therefore, we may determine a transfer role from statistics of amplitudes at collisions to numbers of sediment particles. As results, followings are pointed out.(1)Statistical property of amplitudes strongly depends on diameter of sediment.(2)It is important to know the velocity of flow near the bed or shear velocity. To get the velocity near the bed, a flat faced two dimensional electromagnetic velocity meter attached on the rigid bed such as a top of a consolidation dam. Is useful(3)It is also important to know the limit to apply the estimating method. The limit can be evaluated non-dimensional shear stress and the criteria depend on the bed gradient.According to above discussion, we developed a numerical simulation model of movement and repulsion of sediment particle including riverbed configuration, and discussed the way to determine the transfer matrix from acoustic signal (amplitude) to sediment discharge. We also discuss the integrated system to observe the runoff process of rainfall and sediment in a catchment area.