Sand Wave Numerical Simulation In Taiwan Strait

Sand waves are widely found and documented in the continental shelf area.Sand waves are formed by the tidal current,the sediment erosion,transport and deposition.The environmental parameter change such as local terrain,sediment supply,fluid state,global temperature and water level have a great influence on the sand waves formation,distribution and evolution.Sand waves are often located in the critical water depth of the strong current region,so the dynamic changes of sand waves often affect human activities,such as shipping and near shore construction.With the continuous development of marine energy,the dynamic nature of sand waves will have an impact on the shipping in the shallow water.The dynamic change also constitutes a security risk for submarine facilities.Therefore,the study of sand waves formation mechanism and migration characteristics are important to marine engineering,shipping development and other aspects.Based on the hydrodynamic model FVCOM and the tidal characteristics in the Taiwan Strait,the three-dimensional hydrodynamic model of Taiwan Strait was established.The water depth is unevenly stratified and the simulation results are verified with the measured data including the tide level,tide current and tide direction.The water levels of Taiwan Strait are in good agreement with the results of the three tide stations,and the tidal current is in good agreement with the results of the No.2 buoy.According to the simulation results of the Taiwan Strait,the analysis shows that the waters of the Taiwan Strait are dominated by half day tide,and flows into the middle and south of the Taiwan Strait through two open bounders.On the basis of confirming the good model,the influence of typhoon on the tide velocity and tide direction is analyzed by calculating the typhoon process.In addition,this paper summarizes the methods of sand waves and the characteristics of sand waves in the Taiwan Strait.The distribution of sand waves is analyzed by using FVOCM-SED.Using the empirical formula,the characteristics of sand waves in the middle of the channel are estimated.Finally,through the statistical analysis of typhoon in Taiwan Strait,the influence of two typhoons on sand wave migration is simulated.