Smooth Particle Hydrodynamics Modeling of Coastal Width Influence on Sediment Transport and Shoreline Morphodynamics

Modeling sediment resuspension and transport induced by storm wind in Apalachicola Bay, USA

Modeling of tidal circulation and sediment transport near tropical estuary, east coast of India

Prediction modeling of coastal sediment transport using accelerated smooth particle hydrodynamics approach

The transport of fine sediments and associated chemical constituents originating from potential anthropogenic and natural sources is becoming an issue of increasing importance in the Lower Athabasca River (LAR) ecosystem in northern Alberta, Canada. This study aims to (1) establish an integrated numerical modelling framework to investigate the transport of fine cohesive sediments and associated chemical constituents during both ice-covered and open-water periods and (2) apply the modelling framework to investigate the state and temporal/spatial variation in sediment and selected chemical constituents within the LAR. One-dimensional hydrodynamic and transport models, combined with a river ice model, are used to predict the flow characteristics, transport of sediments and a selection of three metals and three polycyclic aromatic hydrocarbons (PAHs) within a ∼200 km reach of the LAR, both in open-water and ice-covered conditions. The models are validated using available field measurements and are applied to investigate the state and variation of sediment and chemicals for a baseline period as well as to assess the effect of various hypothetical pollution scenarios. The model simulations successfully reproduce the hydrodynamics and sediment transport patterns as well as the state and variation of selected metal and PAH constituents. The results generally show that the concentration of chemical constituents in the bed sediment is the major factor in determining the state and variation of their concentration in the water column, and the high-flow season is the critical period for the transport of sediment and chemicals in the system. The scenario simulation results indicate that increases in the concentrations of chemical constituents in tributary streams have to be orders of magnitude higher to have a noticeable effect on their corresponding water column concentration in the LAR. Those effects are also found to be higher only within the immediate vicinity of the tributary confluences and gradually diminish with distance downstream of the confluences. The numerical modelling framework developed in this study provides a tool for investigation and understanding of the state and temporal/spatial variation of sediment and associated chemical constituents within cold region rivers such as the LAR. By conducting additional scenario-based studies (such as future climate and chemicals loading), the models can be used to identify possible future states of sediment and water quality constituents in the LAR ecosystem.

Sediment transport typically due to combination of gravity acting on the sediment, and/or the movement of the fluid in which the sediment is entrained. This paper gives an exposure simulation of three-dimensional (3D) sediment transports by using Smooth Particle Hydrodynamics (SPH) at coastal area. The SPH formulation from Monaghan constructed in the code is modified according to the desired model to be solved. The code is then computed by using single Graphics Processing Unit (GPU) with 14 cores multiprocessors. The behavior of sediment transport is investigated in this research based on Herschel-Bulkley-Papanastasiou (HBP) model. A constant sinewave of 0.5sin(0.5πt) is applied to the fluid domain to create sea wave effect that will cause sediment transport. The results show that the goal to get sediment transport is achieved and for the further study, the rate of erosion and accretion can be determined to give more meaningful and valuable to the result.

3D Modeling of sediment movement by ships-generated wakes in confined shipping channel

Impacts of tail channel alterations on hydrodynamic and environmental conditions in Yellow River Estuary.

It is a challenge to apply coupled hydrodynamic, sediment process, and contaminant fate and transport models to the studies of surface water systems. So far, there are few published modeling studies on sediment and metal transport in rivers that simulate storm events on an hourly basis and use comprehensive data sets for model input and model calibration. The United States Environmental Protection Agency (USEPA) in 1997 emphasized the need for credible modeling tools that can be used to quantitatively evaluate the impacts of point sources, nonpoint sources, and internal transport processes in 1D/2D/3D environments. A 1D and time-dependent hydrodynamic, sediment, and toxic model, within the framework of the 3D Environmental Fluid Dynamics Code (EFDC), has been developed and applied to Blackstone River, Mass. The Blackstone River Initiative (USEPA) in 1996, a multiyear and multimillion-dollar project, provided the most comprehensive surveys on water quality, sediment, and heavy metals in the river, and served as the primary data set for this study. The model simulates three storm events successfully. The river flow rates are well calculated both in amplitude and in phase. The sediment transport and resuspension processes are depicted satisfactorily. The concentrations of sediment and five metals (cadmium, chromium, copper, nickel, and lead) during the three storm events are also simulated very well. Numerical analyses are conducted to clarify the impacts of contaminant sources and sediment resuspension processes on the river. While point sources are important to sediment contamination in the river, other sources, including nonpoint sources from watershed and bed resuspension, were found to contribute significantly to the sediment and metals in the river. Point sources alone cannot account for the total metals in the river. The model presented in this paper can be a useful tool for studying sediment and metals transport in shallow rivers and for water resource management.

Swash–swash interaction is a common natural phenomenon in the nearshore region, characterized by complex fluid motion. The characteristics of swash–swash interaction are crucial to sediment transport, subsequently affecting the beach morphology. This study investigates the hydrodynamics and sediment transport in swash–swash interaction under two successive solitary waves using a two-phase Smoothed Particle Hydrodynamics (SPH) model. The effects of the time interval between the two waves are examined. It is shown that the time interval has a minor effect on the breaking and swash–swash interacting patterns as well as the final beach morphology but influences the run-up of the second wave and the instantaneous sediment flux. Under wave breaking in the swash–swash interaction, there is significant sediment suspension due to strong vortices, and the suspended sediment forms a plume upward from the bed. The sediment plumes gradually settle down as the vortices decay. These insights enhance the understanding of sediment transport and beach morphology under complex swash–swash interaction.

The sheet-flow sediment transport on sandy slopes under tsunami-like solitary waves is investigated in detail by using a two-phase-resolved Smoothed Particle Hydrodynamics model. The model is well calibrated and verified by simulating the run-up and breaking of solitary waves on both immovable and movable slopes as well as the resulted erosion and deposition on sandy beaches. The profiles of water pressure, two-phase velocities and shear stresses, and sediment fluxes on the sandy slope before and after the breaking of solitary waves are examined. The temporal evolution of bed shear stress, thickness of sheet-flow layer, and sediment transport rate at locations before and after wave breaking is compared. During the run-up of solitary waves, the change of pore water pressure in the sandy slope follows closely with waves resulting in a “high-pressure wave front.” Sediment moves mainly in the thin sheet-flow layer, in which the shear stress of sediment phase is much higher than the fluid stress due to the intense interparticle collision and friction. The profile of bed-parallel sediment flux in the sheet-flow layer presents parabolic with the peak at the layer center. Relationships between the sheet-flow sediment transport rate and Shields number at locations below and above the initial water level are compared. Further numerical experiments show that the solitary wave height has a minor effect on the relationships between sediment transport rate and Shields number below the initial water near the wave-breaking point while enhances the relations in the swash zone above the initial sea surface.

Sediment deposition is a significant feature of a dynamic floodplain river. As the river's carrying capacity decreases, it is forced to deposit sediment on the river bed. However, due to the construction of some hydraulic structures over the river bed at different times (bridges, dams), the velocity of the river in the floodplain area decreases with accelerating sedimentation process, which hinders water transport. The sub-catchment basin (Nabadwip-Kalyani stretch) of the Bhagirathi–Hooghly river in West Bengal (Ghosh et al. 2020), India is frequently used as a means of water transport by local stakeholders. Because of sedimentation, the thalweg depth of the river is constantly decreasing in Nabadwip–Kalyani stretch and the water transport is being disrupted. Therefore, it is very important to know the function of hydraulic structures over the river bathymetry and resultant sediment flow, transportation, and sediment deposition in this region. Therefore, this article mainly assesses to develop a 1D hydro-dynamic sediment transport model on river morphological change through seasonal quasi-unsteady flow accumulation and sediment budget in a given year (2018). The hydro-dynamic model is calibrated by 1D HEC-RAS v 5.0.7 software (Gibson et al. 2017) based on seasonal quasi-unsteady flow using various empirical equations and Manning's roughness coefficient and validated with R2, NSE, and RSR. The model also examines the role of hydrodynamic structures in scouring and sedimentation due to the location of these structures above the river. This model output will help local stakeholders to understand the amount of sediment in the river and keep river transport viable in all seasons.

The goals of this chapter are to (1) describe the processes that govern the transport of sediment in surface waters, (2) provide guidance for use in assessing and/or quantify sediment transport, and (3) describe the procedure to use in modeling sediment transport. A basic knowledge of these topics is requisite to understanding many of the contaminant transport processes important in sediments due to the strong particle associations of most contaminants of concern. This chapter starts with brief overviews of sediment transport – sedimentation related problems and how sediment in surface waters responds to the forces that cause water movement. Basic sediment transport processes are also defined. Section 3.2 describes pertinent properties of sediments, and transport processes for cohesive sediments. Section 3.3 provides guidance to use to assess and/or quantify sediment transport. It is often necessary for remedial project managers to conduct a Sediment Transport Assessment in support of a remedial alternatives evaluation for contaminated sediment Superfund sites. The assessment involves using a systematic approach that (1) identifies the processes and mechanisms that might result in erosion, (2) determines the most appropriate methods to use to assess sediment resuspension and deposition, and (3) quantifies sediment resuspension and deposition rates under varying flow conditions. Section 3.4 provides an overview of the procedures following in performing a sediment transport modeling study. These procedures or steps include: (1) model selection and setup, (2) hydrodynamic modeling, (3) sediment transport modeling, (4) calibration and validation of the models, and (5) analyzing model results.KeywordsSediment TransportSuspended Sediment ConcentrationCritical Shear StressBedload TransportCohesive SedimentThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Sediment is an important factor for excavation, dredging and maintenance of Hengmen Eastern Access Channel in Pearl River Estuary. As storm surge is considered as an important role in determining sediment re-suspension and transport, as well as creating landforms in the areas of estuary and coast, along with the storm surge disaster damage in Pearl River Estuary is one of the most serious events in China, reasonable simulation of storm-induced sediment concentration, transport and channel siltation in Hengmen Eastern Access Channel is of much significance. Based on the feasibility condition of less research on numerical simulation of storm-induced sediment concentration and transport, especially channel siltation in the Pearl River Estuary, using a curvilinear grid, a nested and coupled model which combines typhoon model, hydrodynamic model (Delft3D-FLOW), wave model (Delft3D-WAVE) and sediment transport model (Delft3D-SED) was set up for the region of Pearl River Estuary. After a series of model verifications, which showed that this coupled model performed well to reflect the characteristics of the typhoon field, tidal currents, wave height, storm surge, distribution of suspended sediment in the studied region, the model was applied to study the storm-induced sediment concentration and transport in Hengmen Eastern Access Channel. Through simulation of one extra tropical storm surge process with this coupled numerical model, the storm-induced sediment concentration and transport in Hengmen Eastern Access Channel were studied, and the storm-induced erosion and deposition were further discussed. Results showed that the effect of storm surge on sediment concentration, transport and siltation was significant. Under the influence of storm surge, the velocity and bed stress around Hengmen Eastern Access Channel increased significantly, which led the re-suspension and transport of sediment, and thus, the higher sediment concentration and more channel siltation occurred. By running this coupled model, the simulated results can be employed in the optimum decision making of Hengmen Eastern Access Channel Regulation Project.

Process-based model for nearshore hydrodynamics, sediment transport and morphological evolution in the surf and swash zones

A 2D depth‐averaged hydrodynamic, sediment transport and bed morphology model named STREMR HySeD is presented. The depth‐averaged sediment transport equations are derived from the 3D dilute, multiphase, flow equations and are incorporated into the hydrodynamic model STREMR. The hydrodynamic model includes a two‐equation turbulence model and a correction for the mean flow due to secondary flows. The suspended sediment load can be subdivided into different size classes using the continuum (two‐fluid) approach; however, only one bed sediment size is used herein. The validation of the model is presented by comparing the suspended sediment transport module against experimental measurements and analytical solutions for the case of equilibrium sediment‐laden in a transition from a rigid bed to a porous bed where re‐suspension of sediment is prevented. On the other hand, the bed‐load sediment transport and bed evolution numerical results are compared against bed equilibrium experimental results for the case of a meander bend. A sensitivity analysis based on the correction for secondary flow on the mean flow including the effect of secondary flow on bed shear stresses direction as well as the downward acceleration effect due to gravity on transverse bed slopes is performed and discussed. In general, acceptable agreement is found when comparing the numerical results obtained with STREMR HySeD against experimental measurements and analytical solutions. Copyright © 2007 John Wiley & Sons, Ltd.