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.

中文翻译：

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用于迁移河流床形的混合长度尺度模型

随着水力发电，河川换流器，防洪基础设施的发展，以及对三角洲脆弱生态系统的日益关注，迫切需要评估和监测岩床沉积物质量通量。估算实时床形大小和迁移速度并提供理论框架以将床高程的易于访问的时间历史转换为空间演化模式至关重要。我们在统计稳定，均质，亚临界流量条件下，从实验室水槽和科罗拉多河收集了时空解析的水深。床高程的波数和频谱显示出令人信服的证据，证明了在实验室和现场观察到的迁移床形的等级与速度有关。应用了新的比例定律，根据河床剪切速度，沉积物直径和水深，将迁移速度的全部范围描述为两个无量纲组的函数。进一步的简化产生了一个混合长度的比例模型，该模型可以估计与比例有关的迁移速度，而无需对床形进行分类或识别。