Abstract:
A nested morphodynamic model of the Tongzhou Bay and its surrounding sea areas is set up with ADCIRC+SWAN and Delft3D+SWAN models. All Typhoons that affected the Tongzhou Bay during 1949 to 2019 are classified into five types according to the characteristics of their tracks, and for each type a typical typhoon is selected to drive the model. The morphodynamic changes of the study area induced by the typical typhoons are simulated, and the responses of channel-sand system in Tongzhou Bay and its surrounding sea areas to storm surges are analyzed. The results show that the thickness of sediment erosion and deposition in the planning port area during a typical typhoon process is generally small, within about ±0.40 m. The erosion and sedimentation induced by the north-passing typhoon and the east-passing typhoon are relatively large. Generally, siltation usually occurs outside the entrance of the Basin 3 of the Tongzhou Bay port area, while erosion usually occurs in the Yaosha and Lengjiasha shoals. After a typhoon process, obvious siltation occurred in the outer channel of Lengjiasha in the north of the port area, and obvious erosion occurred in the original Lengjiasha shoal area. Although the amount of siltation/erosion induced by one storm process is not large enough to affect the port operation and navigation, attention should be paid to the impacts of such siltation/erosion in a long-term time scale.