Flow Patterns in Compound Channels with Vegetated Floodplains
Flow Patterns in Compound Channels with Vegetated Floodplains
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DOI：
10.1061/(asce)0733-9429(2007)133:2(148
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发表时间：
2007-02
影响因子：
2.4
通讯作者：
Kejun Yang;S. Cao;D. Knight
中科院分区：
文献类型：
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作者：
Kejun Yang;S. Cao;D. Knight
了解植物泛滥平原复式河道水流的水力学特性，对于确定水位流量曲线和支持河道过程的管理是非常重要的。本文在实验研究的基础上，描述了乔木、灌木和草等不同植被类型上的水流运动规律。对于滩地植被，作者选择塑料草、鸭毛和塑料秸秆分别作为模式草、灌木和乔木。利用三维声学多普勒测速仪对滩地不同植被类型的局部流速进行了测量，并对总流量和水槽坡度进行了独立测量。在没有植被的滩地上，测得的流速分布均服从对数分布，而在植被覆盖的滩地上，流速分布符合S型剖面，表现出三个带。在所有情况下，脉动速度服从正态分布。分析了不同植被类型对二次流、湍流强度和雷诺切应力分布的影响。
Understanding the hydraulics of flow in a compound channel with vegetated floodplains is very important for determining the stage-discharge curve and for supporting the management of fluvial processes. In this paper, the flow patterns over different types of vegetation, such as tree, shrub, and grass, are described, based on an experimental study. For vegetation on the floodplain, the authors choose plastic grass, duck feathers, and plastic straws as model grass, shrubs, and trees, respectively. A 3D acoustic Doppler velocimeter was used to measure the local flow velocities for different types of vegetation on the floodplain, and the total discharge and flume slope were measured independently. In the cases of nonvegetated floodplains, all measured streamwise velocity distributions followed the logarithmic distribution, but for vegetated floodplains, they followed an S-shaped profile, exhibiting three zones. For all cases, the fluctuating velocity followed a normal distribution. The influence of different types of vegetation on the distributions of the secondary currents, turbulence intensities, and Reynolds shear stresses were also analyzed.