Atsushi KARASAWA

Water Exchange Mechanism of the Bohai Sea due to Tidal Current and Wind-driven Current

Tokuzou HOSOYAMADA


Chinese government recently started gthe Drawing South Water to Northh project. However, it is expected that the polluted water from the Bohai Sea discharges into the Yellow Sea with the Yellow river flow rate increased by this project, which would cause adverse affects on the environment of area around the Japan Sea in the long term. For this reason, it is important to analyze the flow mechanism around this area.

This study firstly focused on the water exchange in the Bohai Sea Tidal current and wind-driven current are prevalent in this domain. This study simulated these currents with the three dimensional rectangular coordinate model and investigated the process of the water exchange and polluted water dispersion with visualizing to animated images.

The results show that tidal current produces the horizontal counterclockwise circulation and wind-driven current produces both the horizontal circulation and the vertical circulation in this domain and promotes the water exchange at a speed about twice the speed due to tidal current. Especially, wind-driven current produced in winter promotes it compared to the current produced in summer. By simulating tidal current with considering the outflow from the Yellow River on the assumption of gthe Drawing South Water to Northh also revealed that the project will accelerate the sea water discharge from the Bohai Sea into the East China Sea.