Analysis of Influence on the Bohai Sea Tidal System Induced by Coastline Modification

Four identical hydrodynamic simulation experiments for the Bohai Sea have been implemented respectively with MIKE31 model based on four different coastlines of 2000, 2008, 2010, and 2012, when the intensive usage of the Bohai Sea was carried on. The comparison of these four experiments is used to present the influence on the Bohai Sea tidal system caused by coastline modification. The analysis shows that the semi-diurnal amphidromic point near the Yellow River estuary moves towards south-east gradually as the coastline changes, which makes the semi-diurnal amplitude in Bohai Bay increase and the phase rotate anticlockwise. Meanwhile, the semi-diurnal amplitude in Laizhou Bay becomes smaller and the phase rotates clockwise. Besides, the semi-diurnal amphidromic point near Qinhuang Island moves gradually to southwest. The location of diurnal amphidromic point in Bohai Strait has no obvious changes, but the amplitudes of diurnal tide increase in all three bays.