| Reclamation project is an effective way to alleviate the shortage of land resources and the contradiction between land supply and demand in coastal areas.It not only provides more space for human development and brings huge economic benefits,but also inevitably has an irreversible negative impact on the natural environment.Large scale reclamation activities will change the original topography and natural coastline of the nearby sea area,affect the near sea dynamic environment,and cause a series of ecological and environmental problems.Considering the wave current interaction,this paper studies the influence of reclamation project on the dynamic environment of Bohai Bay,which can provide a scientific understanding of the influence and mechanism of reclamation project on the dynamic environment of coastal waters,and provide some theoretical guidance for the reasonable implementation of reclamation project construction and environmental management planning of the reclamation area in the future.In this paper,FVCOM hydrodynamic model coupled with SWAN model is used to simulate the tidal current field and wave field of Bohai Bay before and after reclamation project,so as to analyze the influence of reclamation project on the dynamic environment of Bohai Bay and the influence of wave on tidal current under wave current interaction.First of all,the FVCOM hydrodynamic model of Bohai Sea area is verified,and the numerical simulation results are well matched with the measured data of tide level and velocity before and after the reclamation project.The simulation results are compared with those of SWAN.Furthermore,coupled with the SWAN model,the surface forcing is added to calculate the tidal current and waves at the same time.The model can simulate the dynamic environment of Bohai Bay,such as tidal current field,wave field and so on.In order to study the impact of shoreline changes caused by reclamation on the dynamic environment of Bohai Bay,2000 and 2010 are selected as the typical years before and after large-scale reclamation.Considering the characteristics of wind field in Bohai Bay,a representative month is selected in winter and summer,and the dynamic environment of Bohai Bay before and after reclamation is simulated in winter and summer respectively.In order to explore the influence of wave current interaction,the simulation is carried out in winter without wave calculation.The simulation results show that the change of flow field and wave field in most sea areas far away from the project area before and after reclamation is very small.Because the reclamation project makes the coastline change more complex,the tidal field and wave field near the reclamation project change.In general,the influence area of large-scale reclamation project on tidal current velocity in Bohai Bay is mainly located near the project area,while the influence on most sea areas far away from the project area is not significant.In addition to Huanghua port and Tianjin port engineering area,the velocity increases after the reclamation,and decreases at the time of rapid fluctuation.The decreasing range of flow velocity at the time of falling is slightly larger than that at the time of rising.Among all the engineering areas,Tianjin port engineering area has a relatively large influence area.After reclamation,except the maximum monthly water level in Caofeidian harbor decreased,the water level in the vicinity of each project area increased.The variation of wave height and period is mainly reflected in the decreasing trend near the project area.The wave current interaction is analyzed,and the simulation results of calculated wave and non calculated wave are compared.It is shown that the influence of wave reduces the simulated water level and velocity,that is,the wave has a certain weakening effect on the tidal current field. |
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