Investigation of hydrodynamics along an embankment generated by a nearby riparian vegetation patch
Investigation of hydrodynamics along an embankment generated by a nearby riparian vegetation patch
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DOI：
10.1007/s11355-022-00535-5
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发表时间：
2022-12
影响因子：
2
通讯作者：
Romitha Wickramasinghe;N. Tanaka
中科院分区：
文献类型：
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作者：
Romitha Wickramasinghe;N. Tanaka
2019年台风海贝斯导致堤坝溢出。溢出物在日本琦玉县的Toki河堤防高度相对较低的地方突破了堤防。实地调查表明，洪水期间，决口附近的河岸竹植被斑块中堆积着草或木质残体。针对这一问题，采用二维k-ε雷诺平均Navier-Stokes（RANS）湍流模型进行了一系列水槽试验和数值模拟，并结合植被模型（VM）和泥石流模型（DM），研究了明渠堤岸沿着流的水动力特性。考虑了VM间隙（即VM与水槽壁之间的差距：d）和VM角度（即VM与水槽壁的角度：θ）的几种配置。将差距相对于VM的交叉流宽度（w）归一化（dnd）（dnd=d/w）。当考虑最大水深、流速和沿沿着的床面剪切力时，建议保持满足dnd> 0.3的植被斑块，避免60°、90°和120°斑块取向。
Typhoon Hagibis in 2019 caused overflow of embankments. The overflow breached the embankment of the Toki River in Saitama Prefecture, Japan, at a point where its height was relatively low. A field survey showed that grass or woody debris piled up in riparian bamboo vegetation patches growing near the breach location during the flooding. In view of this, a series of flume experiments and numerical simulations with a two-dimensional (2D)k−ɛReynolds-averaged Navier–Stokes (RANS) turbulence model were carried out to understand the flow hydrodynamics along the open channel embankment with a vegetation model (VM) and a debris model (DM). Several configurations of the VM gap (i.e. the gap between VM and the flume wall:d) and VM angle (i.e. angle of VM to the flume wall:θ) were considered. The gap was normalized (dnd) with respect to the cross-stream width (w) of the VM (dnd=d/w). When considering the maximum water depth, velocity and bed shear along the side wall, it is recommended that the vegetation patches that satisfydnd> 0.3 be maintained and that 60°, 90° and 120° patch orientations be avoided.