Three-dimensional Hydrodynamic Simulation Of Hecate Strait,Canada

Hecate Strait is located between the mainland of British Columbia,Canada and Queen Charlotte Islands.The topography is varied and complicated.It contains lots of rivers,thus becomes an important waterway transportation and main oil transportation.In order to deal with possible oil spill accident and reduce the risks,the hydrodynamic characteristics of Hecate Strait should be well studied.A coupled model which comprised of the three-dimensional,finite-volume-method ocean model FVCOM,the third generation wave model SWAN and Model Coupling Toolkit is first developed in the present thesis.Then the three-dimensional coupling model with fine grids is applied to Hecate Strait.The forcing of open boundary and wave current interaction are discussed and the hydrodynamic characteristics of Hecate Strait are simulated and analyzed.The content of the paper mainly includes:1.When the tidal level data from global tidal model TPXO7.2 and the ocean current data from HYCOM are used as the boundary forcing for the FVCOM model,the hydrodynamic characteristics of Hecate Strait can be well described.For sea areas influenced by ocean current,it is recommended to use a combined forcing of tide and current.When wave boundary forcing data from the IOWAGA project and the wind forcing data named HRDPS are used for the SWAN model,the wave characteristics can be well described.The coupling model is more accurate than independent wave or ocean model.The wave-current interaction is not obvious in most regions.The wave's influence on current is embodied in alongshore current and depends on wave direction and current direction.2.The moment 2014.4.25 3:00 is taken for example to show the hydrodynamic characteristics of Hecate Strait in normal weather conditions.The three-dimensional structure of flow circulation is not obvious in the whole strait.There's a circulation in the west of Queen Charlotte Sound the vertical-averaged velocity is about 0.49m/s.The current near Dixon Entrance mainly flows from north to south while it flows from southeast to northwest elsewhere.The flow field is regular overall.As for the wave characteristics,the wave height is about 2.5m around Queen Charlotte Sound and 1.5m around Dixon Entrance.Other regions' wave heights are relatively low.3.The moment 2014.2.14 12:00 is taken for example to show the hydrodynamic characteristics of Hecate Strait in extreme weather conditions.The flow field is quite complex around Queen Charlotte Sound.In the east side of the sound,the current flows from east to west with a vertical-averaged velocity of 0.58m/s.In the west side of the sound,the current flows from north to south with a vertical-averaged velocity of 0.77m/s.There're lots of circulations in the whole computational domain while the velocity is not very high.As for the wave characteristics,the maximum wave height is more than 10 m around Queen Charlotte Sound.The average wave height is about 2.5m near Dixon Entrance and more than 4m to the west of Banks Island.Overall the wave height decrease from Queen Charlotte Sound to Dixon Entrance.