The Research On The Impact Of Dynamic Environment In Qingdao Adjacent Sea Due To The Change Of Coscal Line In Jiaozhou Bay And Qingdao Adjacent Sea

Based on a Finite-Volume Coastal Ocean Model, a three dimensional tide and tidal currents system was established using unstructured triangular grids. Assuming little change of the open boundary conditions, this article has compared the hydrodynamic changes of Jiaozhou Bay including tidal water capacity, tide and tidal currents, and water exchange rate under different coastline and water depth in different year of 1935,1966,1986 and 2000 on condition of a accurate simulation of the tides and tidal currents of Jiaozhou Bay and its adjacent area.The conclusions are got from the analysis and comparison of the simulation results as following: the tidal water capacity decreases gradually with the decrease of the water area of Jiaozhou Bay, the tidal water capacity of the year of 2008 reduces by 31.09% than the year of 1935, which is about 3.839×103m3.The largest reduction appeared between the year of 1966 and 1986, with a reduction of 2.335×103m3.The co-tidal chart of M2 tide has changed greatly from 1935 to 2008, particularly the variation of the M2 tidal epoch, which gradually takes less time for the tides propagating from the baymouth to bayhead. The co-tidal charts of other partial tides have also changed, but not much though. The flow field structure is similar in the same period of different ages, however the velocity is decreasing, the average velocity of spring tidal period varied most significantly from 1966 to 1986 and reduced by 17% from 1935 to 2008, according to the average velocity of the feature points; the Eulerian residual currents show a multi-vortex structure and the structure almost kept unchanged, while the location and the size changed little, the strongest Eulerian residual current basically appear near Tuandao, with the maximum velocity of 0.562m/s, 0.546m/s, 0.474m/s, 0.507m/s, 0.43m/s in 1935, 1966, 1986, 2000, 2008 respectively; the general trend of water exchange capacity is decreasing, it reduces by 9.2% from 1935 to 2008, with the annual average of 0.13%, the average half-exchange time is 37.0, 36.7, 39.2, 39.7, 40.8 days in 1935, 1966, 1986, 2000, 2008 respectively.To realize real-time forecasting, the advanced ensemble Kalman filter method has been applied to assimilate the surface flow field data observed by high frequency surface wave radar in August 2008. The comparative experiments of the parameters for advanced ensemble Kalman filter show that the more ensemble members are selected and the larger the time interval is, the better the assimilative results are; the assimilative results from time varying is more close to observed data than that from fixed ensemble members; the average root-mean-square error of U and V decrease by 4.5cm/s and 3.3cm/s respectively after an assimilation of the surface wave radar data for one month using proper parameters.