The sudden sedimentation is a rapid deposition of suspended sediment in a short time, which causes the depth of a channel shallow. It is important for manager, engineer and designer to understand the phenomenon in a harbor. A 3D numerical model of sediment transport based on the coupling of modified FVCOM model, WRF model and SWAN model was established to help estimate the channel siltation due to typhoon in Guangli harbor, which is protected by the double long submerged breakwaters. It is shown from simulated results that the model is able to reflect the changes of tides and currents around the harbor reasonable. The largest deposition thickness of channel appears near the entrance and reaches 1.0m.
Guangli Harbor is located on the southwest coast of Laizhou bay and belongs to Shandong Province. It is a planned harbor, which will have two 8km long submerged breakwaters. There is an existent harbor on the 12km southeast of it, which have two 10.3km submerged breakwaters (Fig. 1). In the sea around the harbors, the characteristic of tide belongs to irregular semidiurnal tide and the average tidal range is 1.6m (Yan et al., 2011). According to survey in field, the mean current velocities around the Guangli harbor are about 0.23m/s during spring tide and about 0.14m/s during neap tide. The ebb current is slightly stronger than the flood one. The coast is the silt-sandy coast. The sediments are usually fine and noncohesive and their transport is driven by the combined actions of tidal currents and waves. Sedimentation physics is complicated including e.g. high-density suspension, hindered settling, consolidation, erosion and deposition.
Here a 3D numerical model based on the coupling of modified FVCOM model, WRF model and SWAN model is developed and applied to investigate sediment transport and estimate the channel siltation of Guangli harbor under the action of No. 9711 Typhoon in summer of 1997.
