Response of dynamics to major human engineering in estuary

Illustrated by the Baiteng sea-closure project and using the two-dimensional hydrodynamic model ccost-2d, the simulations and analysis of the hydrodynamic characteristics of estuary before and after the building of the project were given in this paper. The results showed that after the building of the project, the flow velocity nearby Baiteng levee decreased significantly, while the flow velocity in Jitimen channel increased more than double. The tidal ranges changed small and the low water level was elevated by 0.5m in upstream and downstream of Baiteng lake. The high tide water level of upstream Baijiao station rose and downstream Xiaolin station declined. The type of tide changed so greatly that the times of both high and low tide delayed more than 2h, and the curve of lower high water level at Xiaolin station became gentle.