Positive Feedback Between the Tidal Flat Variations and Sediment Dynamics: An Example Study in the Macro‐Tidal Turbid Hangzhou Bay

Journal of Geophysical Research Oceans, Год журнала: 2023, Номер 128(6)

Опубликована: Май 17, 2023

Abstract Tidal flat variations (curvature) in macro‐tidal turbid bays highly correlate with sediment dynamics. Interactions between tidal flats and dynamics estuaries, like Hangzhou Bay, China, have been studied through a fully validated 3D model by considering high‐turbidity, flocculation, water‐sediment density coupling. Numerical results show that the circulation flux curvature of Andong similar magnitudes along‐estuarine lateral directions, demonstrating important impact geometry on hydrodynamics transport processes. Sediment moves toward southern/northern bank near bottom/surface level curvature. Tidally averaged net is southward reclamation changes channel, modulates transport, then feeds back to evolution subsequently. Bottom friction, nonlinear advection, centrifugal force are dominant forces for inducing circulation, followed Coriolis sediment‐induced baroclinic process. Lateral combined suspended concentration (SSC) profile controls distribution instantaneous tidally fluxes The positively correlates channel bends. increased bends enhances mainly increasing effects force, SSC. This study revealed two‐way feedback system dynamics, which contributes anthropogenic activities geomorphological estuaries worldwide.

Язык: Английский

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Hydrodynamics, erosion and accretion of intertidal mudflats in extremely shallow waters

Journal of Hydrology, Год журнала: 2019, Номер 573, С. 31 - 39

Опубликована: Март 18, 2019

Язык: Английский

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Turbulence Structure and Burst Events Observed in a Tidally Induced Bottom Boundary Layer

Journal of Geophysical Research Oceans, Год журнала: 2022, Номер 127(6)

Опубликована: Май 26, 2022

Abstract In estuarine environments tidal variation affects turbulence and associated sediment transport processes near the bed. situ data from benthic boundary layer of subaqueous Yangtze delta were collected over several cycles are used to gain new insights into structure mobility in layer. Our analysis reveals that turbulent kinetic energy production was balanced by dissipation during flood, while ebb an imbalance found (dissipation > production) attributed advection. Quadrant showed a variability four quadrants with ejections (E) sweeps (S) being dominant equal contributors Reynolds stress resuspension. Increased due advection coincides increase timeshare inward‐ outward‐interaction events, resulting higher contribution sweeps. The outward (O) inward (I) ‐interactions resuspension be negligible. Turbulence intermittency is characterized using frequency, duration, strength, intensity quadrant events. frequency duration controlled bursts 1/3∼1/2 (S), which lead them having limited effects on stress. A comparison settling velocity suggests vertical mainly ejection sweep Inward‐ outward‐interactions appear more important for fine material velocities order 1 mm/s.

Язык: Английский

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Sediment Resuspension Due to Near‐Bed Turbulent Effects: A Deep Sea Case Study on the Northwest Continental Slope of Western Australia

Journal of Geophysical Research Oceans, Год журнала: 2018, Номер 123(10), С. 7102 - 7119

Опубликована: Сен. 17, 2018

Abstract Sediment transport equations often consider a mean velocity threshold for the initiation of sediment motion and resuspension, ignoring event‐based turbulent bursting processes. However, laboratory experiments have suggested that near‐bed resuspension is influenced by intermittent coherent structures. In field, accessibility constraints deployment easily operated equipment has largely prevented further identification understanding such processes, which may contribute to in marine environment. Field were conducted on Northwest Slope, Australia, under conditions where current velocities below estimated measured time‐averaged critical investigate relationship between structures resuspension. Results indicate occur even when are values. The majority flux due ejection sweep events, with lesser contributions from up‐acceleration down‐deceleration (vertical flow) events. Spectral quadrant analysis indicated anisotropic nature Reynolds stresses, wavelet transform revealed group sequences associated These observations, flow was not expected based concepts, reveal events control rather single velocity. This highlights need considering turbulence as significant factor should be investigated inclusion into future modeling.

Язык: Английский

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Identify the impacts of waves and tides to coastal suspended sediment concentration based on high-frequency acoustic observations

Marine Geology, Год журнала: 2018, Номер 408, С. 154 - 164

Опубликована: Дек. 13, 2018

Язык: Английский

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Sediment dynamics on a tidal flat in macro-tidal Hangzhou Bay during Typhoon Mitag

Continental Shelf Research, Год журнала: 2022, Номер 237, С. 104684 - 104684

Опубликована: Фев. 17, 2022

Язык: Английский

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Sediment resuspension due to near-bed turbulent coherent structures in the nearshore

Continental Shelf Research, Год журнала: 2020, Номер 194, С. 104048 - 104048

Опубликована: Янв. 7, 2020

Язык: Английский

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Observation and Parameterization of Bottom Shear Stress and Sediment Resuspension in a Large Shallow Lake

Earth and Space Science, Год журнала: 2023, Номер 10(6)

Опубликована: Июнь 1, 2023

Abstract Parameterizations for bottom shear stress are required to predict sediment resuspension from field observations and within numerical models that do not resolve flow the viscous sublayer. This study assessed three observation‐based ( τ b ) parameterizations, including (a) sum of surface wave mean current (quadratic) ); (b) log‐law = L (c) turbulent kinetic energy TKE using 2 years a large shallow lake. For this system, parameterization w + c was sufficient qualitatively resuspension, since currents orbitals were two major processes found resuspend sediments. However, parameterizations also captured development nepheloid layer hypolimnion associated with high‐frequency internal waves. Reynolds‐averaged Navier‐Stokes (RANS) equation parameterize as summation modeled current‐induced , m wave‐induced ). The performance different in RANS against observations. optimal yielded root‐mean‐square errors 0.031 0.025 Pa, respectively, when set constant canonical drag coefficient. A RANS‐based developed; however, grid‐averaged dissipation did always match local observations, leading O (10) prediction stress. Turbulence‐based should be further developed application flows shear‐free boundary turbulence.

Язык: Английский

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An integrated optic and acoustic (IOA) approach for measuring suspended sediment concentration in highly turbid environments

Marine Geology, Год журнала: 2019, Номер 421, С. 106062 - 106062

Опубликована: Окт. 21, 2019

Язык: Английский

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Vertical sediment distribution mechanism in tidal flats -A case study in Zhoushan Archipelago

Estuarine Coastal and Shelf Science, Год журнала: 2023, Номер 293, С. 108503 - 108503

Опубликована: Сен. 21, 2023

Язык: Английский

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