A Coupled Model of the 1D River Network and 3D Estuary Based on Hydrodynamics and Suspended Sediment Simulation

River networks and estuaries are very common in coastal areas. Runoff from the upper stream interacts with tidal current from open sea in these two systems, leading to a complex hydrodynamics process. Therefore, it is necessary to consider the two systems as a whole to study the flow and suspended sediment transport. Firstly, a 1D model is established in the Pearl River network and a 3D model is applied in its estuary. As sufficient mass exchanges between the river network and its estuary, a strict mathematical relationship of water level at the interfaces can be adopted to couple the 1D model with the 3D model. By doing so, the coupled model does not need to have common nested grids. The river network exchanges the suspended sediment with its estuary by adding the continuity conditions at the interfaces. The coupled model is, respectively, calibrated in the dry season and the wet season. The results demonstrate that the coupled model works excellently in simulating water level and discharge. Although there are more errors in simulating suspended sediment concentration due to some reasons, the coupled model is still good enough to evaluate the suspended sediment transport in river network and estuary systems.

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A Quasi-3D Model for Suspended Sediment Transport by Currents and Waves.

Coastal Engineering 1990 ◽

10.1061/9780872627765.163 ◽

1991 ◽

Author(s):

Irene Katopodi ◽

Jan S. Ribberink

Keyword(s):

Sediment Transport ◽

Suspended Sediment ◽

3D Model ◽

Suspended Sediment Transport

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Numerical Simulation of Flow and Suspended Sediment Transport in the Distributary Channel Networks

Journal of Applied Mathematics ◽

10.1155/2014/948731 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9

Author(s):

Wei Zhang ◽

Qiong Jia ◽

Xiaowen Chen

Keyword(s):

Sediment Transport ◽

Water Level ◽

Suspended Sediment ◽

Suspended Sediment Concentration ◽

Transport Model ◽

Sediment Concentration ◽

Suspended Sediment Transport ◽

Governing Equations ◽

Channel Networks ◽

Distributary Channel

Flow and suspended sediment transport in distributary channel networks play an important role in the evolution of deltas and estuaries, as well as the coastal environment. In this study, a 1D flow and suspended sediment transport model is presented to simulate the hydrodynamics and suspended sediment transport in the distributary channel networks. The governing equations for river flow are the Saint-Venant equations and for suspended sediment transport are the nonequilibrium transport equations. The procedure of solving the governing equations is firstly to get the matrix form of the water level and suspended sediment concentration at all connected junctions by utilizing the transformation of the governing equations of the single channel. Secondly, the water level and suspended sediment concentration at all junctions can be obtained by solving these irregular spare matrix equations. Finally, the water level, discharge, and suspended sediment concentration at each river section can be calculated. The presented 1D flow and suspended sediment transport model has been applied to the Pearl River networks and can reproduce water levels, discharges, and suspended sediment concentration with good accuracy, indicating this that model can be used to simulate the hydrodynamics and suspended sediment concentration in the distributary channel networks.

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Streamflow and suspended-sediment transport in Garvin Brook, Winona County, southeastern Minnesota: Hydrologic data for 1982

Open-File Report ◽

10.3133/ofr83212 ◽

1983 ◽

Author(s):

G.A. Payne

Keyword(s):

Sediment Transport ◽

Suspended Sediment ◽

Suspended Sediment Transport ◽

Hydrologic Data

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2D and 3D CFD Investigations of Seabed Shear Stresses Around Subsea Pipelines

Volume 4A: Pipeline and Riser Technology ◽

10.1115/omae2013-10626 ◽

2013 ◽

Cited By ~ 1

Author(s):

Wenwen Shen ◽

Terry Griffiths ◽

Mengmeng Xu ◽

Jeremy Leggoe

Keyword(s):

Sediment Transport ◽

Suspended Sediment ◽

Interaction Model ◽

Suspended Sediment Transport ◽

Shear Stresses ◽

Parametric Function ◽

Ample Evidence ◽

North West ◽

Wide Range ◽

Subsea Pipelines

For well over a decade it has been widely recognised that existing models and tools for subsea pipeline stability design fail to account for the fact that seabed soils tend to become mobile well before the onset of pipeline instability. Despite ample evidence obtained from both laboratory and field observations that sediment mobility has a key role to play in understanding pipeline/soil interaction, no models have been presented previously which account for the tripartite interaction between the fluid and the pipe, the fluid and the soil, and the pipe and the soil. There are numerous well developed and widely used theories available to model pipe-fluid and pipe-soil interactions. A challenge lies in the way to develop a satisfactory fluid-soil interaction algorithm that has the potential for broad implementation under both ambient and extreme sea conditions due to the complexity of flow in the vicinity of a seabed pipeline or cable. A widely used relationship by Shields [1] links the bedload and suspended sediment transport to the seabed shear stresses. This paper presents details of computational fluid dynamics (CFD) research which has been undertaken to investigate the variation of seabed shear stresses around subsea pipelines as a parametric function of pipeline spanning/embedment, trench configuration and wave/current properties using the commercial RANS-based software ANSYS Fluent. The modelling work has been undertaken for a wide range of seabed geometries, including cases in 3D to evaluate the effects of finite span length, span depth and flow attack angle on shear stresses. These seabed shear stresses have been analysed and used as the basis for predicting sediment transport within the Pipe-Soil-Fluid (PSF) Interaction Model [2] in determining the suspended sediment concentration and the advection velocity in the vicinity of pipelines. The model has significant potential to be of use to operators who struggle with conventional stabilisation techniques for the pipelines, such as those which cross Australia’s North West Shelf, where shallow water depths, highly variable calcareous soils and extreme metocean conditions driven by frequent tropical cyclones result in the requirement for expensive and logistically challenging secondary stabilisation measures.

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