One‐dimensional vertical (1DV) diffusion‐settling models are practical tools for sediment transport analysis of sands, which is mostly a local process. However, for fine sediments, the observed concentrations C(t) can be mixed via horizontal advection (HA) due to the lower settling velocity, which makes the C(t) not necessarily a local process, thus making 1DV models invalid. It is important to determine the qualitative significance of HA or quantitatively separate HA signals when applying 1DV models to environments with advected fine sediments. Here, novel methods are combined to (1) qualitatively identify the physical mechanisms underlying C(t) variations and determine whether HA is significant via multiscale frequency superposition and (2) quantitatively decompose C(t) components according to their physical mechanisms via spectral filter decomposition. In situ observational data of C(t) and concurrent hydrodynamics in the subaqueous Yellow River Delta is employed to analyze the methods' performance. The decomposed signals are reasonable because they can be interpreted in light of other observed physical processes. The results indicated that M2 tidal advection contributed 8.30% by carrying sediments from 1.6 km upstream of the flood tides, M4 and M6 + M8 tidal resuspension contributed 4.16% and 3.96%, respectively, by periodically resuspending a “fluffy layer.” Waves resuspended sediments from an erosion center 5 km upstream of the flood tides and contributed to 76.49% of the elevated C(t). The proposed methods can exclude HA signals from the measured C(t) to increase the applicability of 1DV models to environments with advected fines when C(t) and hydrodynamics are measured.

中文翻译：

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实地测得的悬浮泥沙浓度的多尺度叠加与分解：将1DV模型扩展到建议沉积细沙的沿海海洋的意义

一维垂直（1DV）扩散沉降模型是用于沙土沉积物分析的实用工具，这主要是局部过程。但是，对于较细的沉积物，由于沉降速度较低，可以通过水平对流（HA）混合观察到的浓度C（t），这使得C（t）不一定是局部过程，因此使1DV模型无效。将1DV模型应用于平流细小沉积物的环境时，确定HA的质量重要性或定量分离HA信号非常重要。在这里，结合了新颖的方法来（1）定性地确定C（t）变化，并通过多尺度频率叠加确定HA是否显着，并且（2）通过频谱滤波器分解根据其物理机制对C（t）分量进行定量分解。在原位观测数据Ç（吨），并利用黄河三角洲水下流体动力学同时分析了该方法的性能。分解后的信号是合理的，因为可以根据其他观察到的物理过程对其进行解释。结果表明，M2潮平流通过携带潮汐上游1.6 km处的沉积物贡献了8.30％，M4和M6 + M8潮汐的悬浮通过周期性地重悬“蓬松层”分别贡献了4.16％和3.96％。波浪将潮汐上游5 km侵蚀中心的沉积物重悬，占升高的C（t）的76.49％。所提出的方法可以从测量的C（t），以提高1DV模型在测量C（t）和流体动力学时对有罚金的环境的适用性。