Although shear layers generated by submerged vegetation reach a steady state once production and dissipation are balanced within a canopy, shear layers found in gaps and after trailing edges of canopy patches are inherently different and thereby perturb the canopy's mean and turbulent fields. Experiments were conducted in a laboratory flume to study canopy systems in which two model patches of submerged, rigid cylinder arrays are interrupted by a gap of varying stream‐wise lengths. Results show that, consistent with past studies, gaps locally enhance turbulence. However, this perturbation does not remain “local” within the gap, instead introducing enhanced turbulent energies throughout the water column that are transported downstream and thereby perturb the canopy flow. The study suggests a scaling, , which compares the eddy turnover time of the turbulence produced by the gap to the advection time downstream the second patch, that can be used to predict if turbulence perturbations induced by an upstream gap will influence the turbulence at a given distance downstream.

中文翻译：

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缝隙对淹没冠层流量的局部和非局部影响

尽管一旦植被在顶棚内产生和消散达到平衡，由淹没植被产生的剪切层便达到稳态，但在缝隙中以及在顶棚斑块的后缘之后发现的剪切层本质上是不同的，从而扰乱了顶棚的平均和湍流场。在实验室水槽中进行了实验，研究了冠层系统，其中，淹没的刚性圆柱体阵列的两个模型斑块被沿河段长度变化的间隙打断。结果表明，与以往的研究一致，间隙局部增强了湍流。但是，这种扰动不会在间隙内保持“局部”，而是会在整个水柱中引入增强的湍流能量，这些能量会向下游输送，从而扰动冠层流量。研究表明，，它比较了由间隙产生的湍流的涡流转换时间与第二个斑块下游的对流时间，可用于预测上游间隙引起的湍流扰动是否会影响下游给定距离的湍流。