A Mixed Length Scale Model for Migrating Fluvial Bedforms
A Mixed Length Scale Model for Migrating Fluvial Bedforms
复制标题
迁移河床形态的混合长度比例模型
DOI：
10.1029/2019gl086625
复制
发表时间：
2020
影响因子：
5.2
通讯作者：
P. Grams
中科院分区：
文献类型：
--
作者：
M. Guala;M. Heisel;Ashutosh Kumar Singh;M. Musa;D. Buscombe;P. Grams
随着水电、河内水电站、防洪基础设施的建设和对三角洲脆弱生态系统的日益关注，对河床泥沙通量的评价和监测迫在眉睫。估算实时床层尺寸和迁移速度，并提供一个理论框架，将床层高程的时间历史转换为空间演化模式，这是至关重要的。我们收集了实验室水槽和科罗拉多河在统计稳定、均匀、亚临界流动条件下的时空分辨率测深数据。在实验室和野外观测到的迁移层状结构中，波数和床高程频谱显示了令人信服的速度依赖于尺度的证据。应用新的标度律描述了基于河床剪切速度、沉积物直径和水深的两个无量纲群的全范围迁移速度函数。进一步的简化产生了一个混合长度尺度模型，可以估计依赖于尺度的迁移速度，而不需要对床型进行分类或识别。
With the expansion of hydropower, in‐stream converters, flood‐protection infrastructures, and growing concerns on deltas fragile ecosystems, there is a pressing need to evaluate and monitor bedform sediment mass flux. It is critical to estimate real‐time bedform size and migration velocity and provide a theoretical framework to convert easily accessible time histories of bed elevations into spatially evolving patterns. We collected spatiotemporally resolved bathymetries from laboratory flumes and the Colorado River in statistically steady, homogeneous, subcritical flow conditions. Wave number and frequency spectra of bed elevations show compelling evidence of scale‐dependent velocity for the hierarchy of migrating bedforms observed in the laboratory and field. New scaling laws were applied to describe the full range of migration velocities as function of two dimensionless groups based on the bed shear velocity, sediment diameter, and water depth. Further simplification resulted in a mixed length scale model estimating scale‐dependent migration velocities, without requiring bedform classification or identification.
影响因子：
5.8
作者：
A. Nicholas;Greg . Smith;M. Amsler;P. Ashworth;J. Best;R. Hardy;S. Lane;O. Orfeo;D. Parsons;A. Reesink;S. Sandbach;C. Simpson;R. Szupiany
通讯作者：
A. Nicholas;Greg . Smith;M. Amsler;P. Ashworth;J. Best;R. Hardy;S. Lane;O. Orfeo;D. Parsons;A. Reesink;S. Sandbach;C. Simpson;R. Szupiany