Impact of fluffy layer and bedform on turbulent intermittency in tidally induced bottom boundary layer

IF 2.6 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Marine Geology Pub Date : 2026-01-01 Epub Date: 2025-10-29 DOI:10.1016/j.margeo.2025.107677

Zhixin Cao, Chao Li, Zhenkun Lin, Yaokun Lin, Zhaohui Deng, Jiaxue Wu, Jie Ren

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引用次数: 0

Abstract

Bed roughness affects the turbulence structure within the bottom boundary layer (BBL), thus playing a significant role in sediment resuspension and transport. This study collected in-situ turbulence and sediment data within the BBL of the Pearl River Estuary (PRE) using a benthic quadrapod observation system. Based on quadrant analysis results, the presence of ripples leads to increased bed roughness, which enhances ejections and sweeps. We also find that sweep and ejection events possess stronger sediment mobilization capacity and higher transport efficiency, rather than simply having a larger time proportion. Additionally, under low bed shear stress, the presence of a fluffy layer makes the contribution of inward interactions to sediment flux during flood tide particularly significant. Consequently, we improved the method for determining the waiting time of the sediment flux intermittency index to identify the erosion of consolidated sediment layers.

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蓬松层和床型对潮致底边界层湍流间歇性的影响

河床粗糙度影响底边界层湍流结构，在泥沙再悬浮和输运中起重要作用。本研究利用底栖四足动物观测系统，收集了珠江口BBL内的湍流和泥沙资料。根据象限分析结果，波纹的存在导致床层粗糙度增加，从而增强喷射和扫射。我们还发现，横扫和喷射事件具有更强的泥沙动员能力和更高的输沙效率，而不是简单地具有更大的时间比例。此外，在低床层剪切应力下，松软层的存在使得向内相互作用对涨潮期间泥沙通量的贡献尤为显著。因此，我们改进了确定沙通量间歇指数等待时间的方法，以识别固结沉积层的侵蚀。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Marine Geology 地学-地球科学综合

CiteScore

6.10

自引率

6.90%

发文量

175

审稿时长

21.9 weeks

期刊介绍： Marine Geology is the premier international journal on marine geological processes in the broadest sense. We seek papers that are comprehensive, interdisciplinary and synthetic that will be lasting contributions to the field. Although most papers are based on regional studies, they must demonstrate new findings of international significance. We accept papers on subjects as diverse as seafloor hydrothermal systems, beach dynamics, early diagenesis, microbiological studies in sediments, palaeoclimate studies and geophysical studies of the seabed. We encourage papers that address emerging new fields, for example the influence of anthropogenic processes on coastal/marine geology and coastal/marine geoarchaeology. We insist that the papers are concerned with the marine realm and that they deal with geology: with rocks, sediments, and physical and chemical processes affecting them. Papers should address scientific hypotheses: highly descriptive data compilations or papers that deal only with marine management and risk assessment should be submitted to other journals. Papers on laboratory or modelling studies must demonstrate direct relevance to marine processes or deposits. The primary criteria for acceptance of papers is that the science is of high quality, novel, significant, and of broad international interest.