A Two‐Layer Turbulence‐Based Model to Predict Suspended Sediment Concentration in Flows With Aquatic Vegetation
A Two‐Layer Turbulence‐Based Model to Predict Suspended Sediment Concentration in Flows With Aquatic Vegetation
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DOI：
10.1029/2020gl091255
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发表时间：
2021-01
影响因子：
5.2
通讯作者：
C. Tseng;R. Tinoco
中科院分区：
文献类型：
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作者：
C. Tseng;R. Tinoco
传统的基于床面剪应力的模型（例如，Rouse模型）不能准确预测有水生植被的水流中的悬浮泥沙浓度（SSC）。我们开发了一个两层湍流模型来预测紧急植被流中的SSC剖面。近床湍动能（TKE）中考虑了植被、河床和干-床-流相互作用引起的拟序结构产生的湍流，以计算有效床面剪切速度ubeff*。该模型通过实验数据验证，进一步表明近床层（有效底部边界层）的厚度高度Hb随流速和郁闭度而变化。提供了两个额外的模型来估计Hb和ubeff*。该模型有望为未来研究植被河流、湿地和河口的泥沙输移、景观演变和水质管理提供重要信息。
Traditional bed shear stress‐based models (e.g., Rouse model) derived from the classic parabolic profile of eddy viscosity in open‐channel flows fail to accurately predict suspended sediment concentration (SSC) in flows with aquatic vegetation. We developed a two‐layer, turbulence‐based model to predict SSC profiles in emergent vegetated flows. Turbulence generated from vegetation, bed, and coherent structures caused by stem‐bed‐flow interaction are considered into the near‐bed turbulent kinetic energy (TKE) to calculate the effective bed shear velocity, ubeff* . The model, validated by experimental data, further showed that the thickness height of the near‐bed layer (effective bottom boundary layer), Hb, varies with flow velocity and canopy density. Two additional models are provided to estimate Hb and ubeff* . The model is expected to provide critical information to future studies on sediment transport, landscape evolution, and water quality management in vegetated streams, wetlands, and estuaries.