Clarification of Vortex Formations and Velocity Fluctuations in Rivers by Detailed Measurement and Their Applications

在小涡到大涡复杂出现的河流弯道水事故危险区，采用多普勒式三维测速仪和水流剖面仪并行进行了移动观测和定点观测。还进行了其他实验。结果表明，河床地形的变化十分剧烈，水流呈现出深冲、沿壁状河床驼峰上涌、再深冲的趋势。评估了速度波动和当前方向变化的时空尺度和频率特性。

At a river bend known as a danger spot of water accidents where small to large sized vortices appear complicatedly, moving observations and fixed point observations were carried out in parallel with an acoustic Doppler type of 3D velocity meter and those of current profilers. Additional experiments also were conducted. As the results, very sharp changes in riverbed topography are shown minutely and flows are clarified as plunge into deep part, well up along wall-like riverbed hump and plunge into again. Spatial-temporal scales and frequency properties of velocity fluctuations and changes in current directions are evaluated.