Numerical Simulation Study On The Impact Of Sea Level Rise On The Hydrodynamics Of Zhoushan Sea Area

Zhoushan Archipelago,commonly known as the "city of thousands of islands",is located in the east of Zhejiang Province.It is an important port city in Zhejiang Province and has the world’s largest port "Ningbo Zhoushan port".This is mainly due to the superior geographical location of Zhoushan Islands and the good regional ecological environment between the islands,but the superior geographical environment will also face many difficult problems,such as water pollution in Zhoushan sea area and the impact of storm surge.These problems have a negative impact on the social and economic development of Zhoushan sea area.Due to the large number of islands in Zhoushan sea area and complex and changeable terrain,Therefore,the hydrodynamic environment of Zhoushan sea area is very complex.In recent years,due to the rise of global temperature,a large number of glaciers have melted,resulting in the rise of global average sea level.These factors have prompted the change of hydrodynamic forces in Zhoushan sea area,and have a far-reaching impact on the natural environment and social economy of Zhoushan sea area.In this thesis,FVCOM(Finite-Volume Communtiy Ocean Model)model is used to conduct an in-depth study on the impact of sea-level rise on the hydrodynamic force and water environment in Zhoushan sea area,so as to deal with the changes of sea-level rise on the hydrodynamic environment in Zhoushan sea area in the future,and provide help for the subsequent utilization of marine resources.Firstly,the three-dimensional hydrodynamic FVCOM(Finite-Volume Communtiy Ocean Model)model is used to simulate the hydrodynamic environment in Zhoushan sea area,and the measured tide level,tidal current velocity and flow direction data are used for comparison and verification.Then,based on the debugged model,the sea level is increased by 1m,and then the hydrodynamic environment after rising is compared with that before rising.The research results show that:(1)The tidal level change trend of stations near Zhoushan is basically unchanged,the tidal range decreases slightly,the tidal current velocity increases,the arrival time of high and low tides is 5-6 minutes ahead of schedule,the surface residual current increases and the bottom residual current decreases slightly.(2)In terms of tidal harmonic constant,the tidal current of K1 tidal component is greatly affected by the change of sea level.The areas with large changes are the Western sea area of Daishan and the Western sea area of Meishan Island respectively;In terms of tidal level harmonic constant,the M2 and S2 component tides are weakened to a certain extent,but the opposite phenomenon occurs in the northwest sea area of Zhoushan Island,and the lag angle is basically unchanged.In the sea area near Zhoushan Island,the lag angle of K1 and O1 component tides is reduced to a small extent.(3)The tracer diffusion range in shallow water area decreases as the particle trajectory range increases,while the tracer diffusion range in deep water area basically stays the same.The closer to the estuary,the tracer diffusion range is more affected by sea level change.