3D Hydrodynamic Modeling of Sediment Dynamics on Roberts Bank, Fraser River Foreslope, Strait of Georgia, Canada
14 Jul 2006-pp 806-823
TL;DR: In this article, a fully three-dimensional, nested grid, integrated circulation-wave-sedimentgeomorphology numerical model, COCIRM-SED, was developed to study sediment dynamics on Roberts Bank, Fraser River foreslope, Strait of Georgia, Canada.
Abstract: A fully three-dimensional, nested grid, integrated circulation-wave-sedimentgeomorphology numerical model, COCIRM-SED, was developed to study sediment dynamics on Roberts Bank, Fraser River foreslope, Strait of Georgia, Canada. Roberts Bank is an extensive intertidal zone, located just south of where the main (South Arm) Fraser River channel enters the Strait of Georgia. The substrate of Roberts Bank is primarily silty sand, and a total of four grain size classes were considered in the model. The study area of interest is modeled using a fine grid size of 100 m by 100 m, and is nested within the much larger domain of the Strait of Georgia with a coarser grid size of 500 m by 500 m. These two model domains are solved together at every time step using a fully dynamic and two-way connection scheme. Following initial testing with idealized analytical cases, the COCIRM-SED modeled flows and suspended sediment concentration were calibrated and verified using the data obtained with a configurable multi-sensor tripod system on the Bank and at the edge of the Bank, respectively. These field data, including month-long ADCP current profiles, OBS sediment concentrations, and directional wave measurements, are used to examine the model performance. The preliminary model results provide improved understandings of the sediment dynamics on Roberts Bank.
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TL;DR: Chatham Sound, a semi-enclosed inland sea located off northern British Columbia, is an important waterway due to many proposed industrial activities related to the Port of Prince Rupert, along with...
Abstract: Chatham Sound, a semi-enclosed inland sea located off northern British Columbia, is an important waterway due to many proposed industrial activities related to the Port of Prince Rupert, along with...
7 citations
Cites methods from "3D Hydrodynamic Modeling of Sedimen..."
...…resolution 3D finite-difference numerical model, Coastal Circulation Model for Sediment transport (COCIRM-SED; e.g., Jiang, Fissel, & Topham, 2003; Jiang & Fissel, 2006; Jiang, Fissel, & Borg, 2008; Jiang & Fissel, 2010; Jiang & Fissel, 2012)), is developed and applied to derive the tidal and…...
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25 Aug 2008
TL;DR: In this article, a three dimensional integrated numerical model, COCIRM-SED, was applied to predict the sediment plumes and deposition resulting from the removal and installation activities of existing and proposed underwater transmission cables across the Strait of Georgia, British Columbia, Canada.
Abstract: A three dimensional, integrated numerical model, COCIRM-SED, was applied to predict the sediment plumes and deposition resulting from the removal and installation activities of existing and proposed underwater transmission cables across the Strait of Georgia, British Columbia, Canada. In the model, a total of six sediment categories from fine silt to medium sand were classified and simulated together in terms of sampled sediment characteristics. The model results were obtained with a trenching rate of 300 m/h and two trench sizes, a wide trench of 1.0 m wide 1.0 m deep and a narrow trench of 0.2 m wide 1.0 m deep. The amount of sediment that is suspended above the trench was taken to be 30% of the total volume for the wide trench and 25% for the narrow trench. The detailed model results of total suspended sediment values, plumes and depositions are reported in this paper.
6 citations
19 Dec 2011
TL;DR: In this paper, the highly integrated, three-dimensional finite difference COastal CIRculation Model COCIRM-SED was adapted and optimized to predict the sediment transport processes associated with a number of coastal engineering projects in Roberts Bank, Canoe Pass and Brown Passage, British Columbia, Canada.
Abstract: Quantitative understandings of sediment transport for coastal engineering projects, such as removing and installing underwater cables, installing and operating underwater turbines and disposal of dredged marine sediment (or terrestrial overburden) are one of the key requirements in planning these projects, assessing potential environmental impact and obtaining regulatory approvals from government agencies In support of the environmental assessment and approval, the highly-integrated, three-dimensional finite difference COastal CIRculation Model COCIRM-SED was recently adapted and optimized to predict the sediment transport processes associated with a number of coastal engineering projects in Roberts Bank, Canoe Pass and Brown Passage, British Columbia, Canada In these applications, the circulation module was validated using historical ocean current data located in the study areas
2 citations
Cites background from "3D Hydrodynamic Modeling of Sedimen..."
...The circulation module (COCIRM), developed over the past decade ([1], [2], [3]), represents a computational fluid dynamics approach to the study of river, estuarine and coastal circulation regimes....
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...Background levels of 25 to 50 mg/L, and more during freshet (snow melting from May to August), are expected to occur in the Fraser River plume and the shallow portions of the Fraser River delta (Jiang and Fissel, 2006)....
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TL;DR: In this article, a high-resolution 3D finite difference hydrodynamic model, COastal CIRculation and SEDiment transport Model (COCIRM-SED), was developed in 2010 and 2013 to determine the tidal and wind-driven currents of this area.
Abstract: Brown Passage is a deep (up to 200 m) ocean channel connecting the western offshore waters of Hecate Strait and Dixon Entrance on the Pacific continental shelf with the eastern inland waters of Chatham Sound in Northern British Columbia, Canada. A high-resolution 3D finite difference hydrodynamic model, COastal CIRculation and SEDiment transport Model (COCIRM-SED), was developed in 2010 and 2013 to determine the tidal and wind-driven currents of this area. The barotropic model results for ocean currents were found to be in reasonably good agreement with the historical ocean current observations at near-surface and middle depth available for Brown Passage. Operated from October 2014 to April 2015, the first modern oceanographic measurement program in Brown Passage found surprisingly strong near-bottom currents (the 99th percentile current speed reaches 53 cm/s at 196 m). As a result, the COCIRM-SED model was modified and rerun, with the most important change incorporating water density/salinity fields as modeled variables. This change led to considerable improvements in the ability of the model to generate episodes of relatively strong currents in the bottom layers. The bottom intensification in ocean currents in Brown Passage is shown to be due to semi-diurnal internal tides, which were not previously included in the barotropic version of the 3D model. This finding for the near-bottom flow from the qualitative modeling study is important for applications of the potential sediment deposition and resuspension studies.
1 citations
References
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TL;DR: The second-moment turbulent closure hypothesis has been applied to geophysical fluid problems since 1973, when genuine predictive skill in coping with the effects of stratification was demonstrated as discussed by the authors.
Abstract: Applications of second-moment turbulent closure hypotheses to geophysical fluid problems have developed rapidly since 1973, when genuine predictive skill in coping with the effects of stratification was demonstrated. The purpose here is to synthesize and organize material that has appeared in a number of articles and add new useful material so that a complete (and improved) description of a turbulence model from conception to application is condensed in a single article. It is hoped that this will be a useful reference to users of the model for application to either atmospheric or oceanic boundary layers.
6,488 citations
"3D Hydrodynamic Modeling of Sedimen..." refers background or methods in this paper
...The model applies the fully three-dimensional basic equations of shallow water hydrodynamics and conservative mass transport combined with a second order turbulence closure model (Mellor and Yamada, 1982), where the pressure is simply assumed hydrostatic, then solves for time-dependent, three-dimensional velocities, salinity, temperature, suspended sediment concentrations and coarse sediment bed-loads by size category, turbulence kinetic energy and mixing length, horizontal and vertical diffusivities, water surface elevation, 2D wave spectra, wave forces, and bottom elevation variations....
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...…basic equations of shallow water hydrodynamics and conservative mass transport combined with a second order turbulence closure model (Mellor and Yamada, 1982), where the pressure is simply assumed hydrostatic, then solves for time-dependent, three-dimensional velocities, salinity,…...
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TL;DR: In this article, a method is presented which enables the computation of the bed-load transport as the product of the saltation height, the particle velocity and the bed load concentration.
Abstract: A method is presented which enables the computation of the bed-load transport as the product of the saltation height, the particle velocity and the bed-load concentration. The equations of motions for a solitary particle are solved numerically to determine the saltation height and particle velocity. Experiments with gravel particles (transported as bed load) are selected to calibrate the mathematical model using the lift coefficient as a free parameter. The model is used to compute the saltation heights and lengths for a range of flow conditions. The computational results are used to determine simple relationships for the saltation characteristics. Measured transport rates of the bed load are used to compute the sediment concentration in the bed-load layer. A simple expression specifying the bed-load concentration as a function of the flow and sediment conditions is proposed. A verification analysis using about 600 (alternative) data shows that about 77% of the predicted bed-load-transport rates are within 0.5 and 2 times the observed values.
1,653 citations
TL;DR: In this article, a method is presented which enables the computation of the suspended load as the depth-integration of the product of the local concentration and flow velocity, based on the calculation of the reference concentration from the bed-load transport.
Abstract: A method is presented which enables the computation of the suspended load as the depth-integration of the product of the local concentration and flow velocity. The method is based on the computation of the reference concentration from the bed-load transport. Measured concentration profiles have been used for calibration. New relationships are proposed to represent the size gradation of the bed material and the damping of the turbulence by the sediment particles. A verification analysis using about 800 data shows that about 76% of the predicted values are within 0.5 and 2 times the measured values.
1,564 citations
TL;DR: In this paper, an analytical theory is presented to describe the combined motion of waves and currents in the vicinity of a rough bottom and the associated boundary shear stress, and the resulting linearized governing equations are solved for the wave and current kinematics both inside and outside the wave boundary layer region.
Abstract: An analytical theory is presented to describe the combined motion of waves and currents in the vicinity of a rough bottom and the associated boundary shear stress. Characteristic shear velocities are defined for the respective wave and current boundary layer regions by using a combined wave-current friction factor, and turbulent closure is accomplished by employing a time invariant turbulent eddy viscosity model which increases linearly with height above the seabed. The resulting linearized governing equations are solved for the wave and current kinematics both inside and outside the wave boundary layer region. For the current velocity profile above the wave boundary layer, the concept of an apparent bottom roughness is introduced, which depends on the physical bottom roughness as well as the wave characteristics. The net result is that the current above the wave boundary layer feels a larger resistance due to the presence of the wave. The wave-current friction factor and the apparent roughness are found as a function of the velocity of the current relative to the wave orbital velocity, the relative bottom roughness, and the angle between the currents and the waves. In the limiting case of a pure wave motion the predictions of the velocity profile and wave friction factor from the theory have been shown to give good agreement with experimental results. The reasonable nature of the concept of the apparent bottom roughness is demonstrated by comparison with field observations of very large bottom roughnesses by previous investigators. The implications of the behavior predicted by the model on sediment transport and shelf circulation models are discussed.
1,412 citations
Book•
01 Jan 1978
TL;DR: In this paper, the authors define the wide scope of sedimentology, as they see it, a scope which may be broader than that of some of their colleagues, and suggest that a critical synthesis of this field is a matter of importance and urgency.
Abstract: This book has been written in response to the rapid expansion and diversification of sedimentology during the last 30 years. We believe that a critical synthesis of this field is a matter of importance and urgency. The study of sedimentology involves a dynamic interplay with many of the other branches of geology. Its tools range from those used to measure the submicroscopic to ones involving the use of radar, the reflection seismograph, and Earth satellites. In the introduction of Part I we define the wide scope of sedimentology, as we see it, a scope which may be broader than that of some of our colleagues. Actually sedimentology is such an unfamiliar term to some geologists that it has not yet become a heading in the index section of the Bibliography and Index of Geology. This book is intended to be used as a text in undergraduate and graduate courses of sedimentology. In writing this book we have aimed primarily at junior and senior students. Our style of writing in the early chapters is consistent with lower-level undergraduate courses, but we believe that as the student advances he or she progressively should become accustomed to a more professional style. Therefore, the later chapters are written at a professional level. To those who simply scan the book, this lack of uniformity may seem perplexing, but it is deliberate and has the student in mind. Beginning graduate students in sedimentology will also find this text useful. Chapters 8 to 14, especially Chapters 8, 10, 11, and 12, are central to the professional geologist employed in oil and gas exploration or exploitation, and in the study of groundwater or economic geology either in industry or government. Chapter 9 may be of interest to geologists concerned with environment.
817 citations