David B. Fissel

Bio: David B. Fissel is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 4 citations.

3D Hydrodynamic Modeling of 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.

The Ocean Circulation of Chatham Sound, British Columbia, Canada: Results From Numerical Modelling Studies Using Historical Datasets

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...

Sediment Plume and Deposition Modeling of Removal and Installation of Underwater Electrical Cables on Roberts Bank, 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.

Three-dimensional numerical modeling of sediment transport for coastal engineering projects in 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

Baroclinic Effect on Modeling Deep Flow in Brown Passage, BC, Canada

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.