THE STUDY ON HYDRODYNAMIC AND TIDAL WATER CAPACITY IMPACTED BY THE PLANNING OF DINGZI BAY

The planning of Dingzi Bay will impact its hydrodynamic and tidal water capacity,thus affecting the water exchange as well as the water quality and ecological environment in Dingzi Bay.In this paper,the tidal current numerical model is developed by two-dimensional tidal motion equation in the west area of Laoshantou to Gulongzui.And the hydrodynamic and tidal water capacity changes are simulated before and after the planning implementation. The simulation results show that the current velocity in most planning regions will increase after the planning implementation,especially in the middle waterway of Dingzi Bay.During flood tide period,the increment of current velocity near the mouth of waterways is the most with more than 0.48m/s,while the maximum increment of ebb tide occurs near Mahe Port Bridge in 0.54m/s or more.However,the velocity changes little in the area outside the Bay. With respect to tidal prism,it will increase by 42% in the connection line of the Hai-Ji sea-crossing bridge and by 33% in the line connecting the Dingzizui and Kaolao island. All the analysis shows that the planning of Dingzi Bay will greatly improve its water dynamic,and increase its tidal water capacity.Therefore the planning is in favor of water exchange of Dingzi Bay and the open sea.the water quality ecological environment in Dingzi Bay will also be improved as well.