Turbulence Dictates Bedload Transport in Vegetated Channels Without Dependence on Stem Diameter and Arrangement
Turbulence Dictates Bedload Transport in Vegetated Channels Without Dependence on Stem Diameter and Arrangement
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DOI：
10.1029/2021gl095316
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发表时间：
2021-10
影响因子：
5.2
通讯作者：
T. Zhao;H. Nepf
中科院分区：
文献类型：
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作者：
T. Zhao;H. Nepf
植被为沿海洪水和侵蚀提供了基于栖息地和自然的解决方案，引起了人们对其恢复的极大兴趣，这需要了解沉积物的输送和滞留。实验室实验通过考虑不同茎直径和混合直径的阵列，研究了茎直径和排列对底质沉积物输送的影响。据观察，床质输送速率取决于湍流动能，而不取决于茎直径，这与泥沙夹带的脉冲模型一致。现有的基于床剪应力的裸床床土输送预测因子根据湍流进行了重新设计。新的基于湍流的模型预测了在模型冠层中测量的沉积物迁移，这些条件是根据之前的几项研究得出的。还描述了基于生物量和速度的湍流预测，为预测真实植被形态冠层中的湍流和床质输送迈出了重要一步。
Vegetation provides habitat and nature‐based solutions to coastal flooding and erosion, drawing significant interest in its restoration, which requires an understanding of sediment transport and retention. Laboratory experiments examined the influence of stem diameter and arrangement on bedload sediment transport by considering arrays of different stem diameter and mixed diameters. Bedload transport rate was observed to depend on turbulent kinetic energy, with no dependence on stem diameter, which was shown to be consistent with the impulse model for sediment entrainment. Existing predictors of bedload transport for bare beds, based on bed shear stress, were recast in terms of turbulence. The new turbulence‐based model predicted sediment transport measured in model canopies across a range of conditions drawn from several previous studies. A prediction of turbulence based on biomass and velocity was also described, providing an important step toward predicting turbulence and bedload transport in canopies of real vegetation morphology.