The Effects Of Shoreline Change On The Hydrodynamic Environment Of The Jiaozhou Bay

This paper is based on FVCOM ocean model, focused on data stimulation of gulf hydrodynamic environment including tidal volume,tide,current and water exchange capacity in 1966, 1986, 20000 and 2008. We compared these data stimulations and concluded the changes of Jiaozhou bay coastline in different periods and the principle of Jiaozhou bay coastline dynamical environment changes. The stimulation of water dynamical was adopted from FVCOM,only tidal forcing was concerned in open boundary. M 2,S 2,N 2,O1,K 1 and P1 main tidal were chosen. The results showed a great change in the entire Jiaozhou bay coastline and water depth as well as a decrease in sea area in the recent 40 years due to continual reclamation. The spread of tidal near Jiaozhou bay was further influenced. Hence, the water dynamical environment in Jiaozhou bay has been changed obviously.Reclamation resulted in a decrease of satisfied tidal volume at present in Jiaozhou bay to 6.5% of that in 1966. This change further caused a differentiation in Jiaozhou bay tidal wave system. The amplitude of M2 tide diminished 3cm compared to that in 1966 and the phase increased approximately 30°. The trend in Huangdao maritime space changed significantly. Before reclamation, only one brance in opposite direction of the east side of the main trend existed to the west of Huangdao and there was a strong flow to the south. The result of stimulation in 2008 demonstrates that both of the flows disappeared. The trend of velocity in the bay, especially around the entrance of the bay, decreased apparently in 2008 compared to that in 1966. The mean velocity of u at the entrance of the Jiaozhou bay diminished from 1.5m/s in 1966 to 0.7m/s in 2008 and The mean velocity of v decreased from 1.0m/s to 0.5m/s. In addition, the vortex structure of flow intensity in the bay dropped at different level. The dominant change was clockwise vortex flow at the both side of Cangkou watercourse. This change showed close relationship with the satisfied tidal volume resulting from reclamation and the reduce of the trend of intensity. During 1966 and 2008, the entire water exchange rate of Jiaozhou bay decreased gradually. In the recent 40 years, 30-day water exchange rate of Jiaozhou bay was declined 7.5%. This is related to the decrease of gulf velocity.