Research On The Ecological Transformation Of The Surrounding Port

Breakwater is the main engineering measure for the port located on the open coast,which is used to prevent waves and sand,form an encircling harbor basin,protect the environment and reduce sediment deposition.However,the construction of breakwater will affect the marine ecological environment.How to optimize the design and construction scheme of breakwater and give consideration to the port engineering function and regional ecological function is the difficult problem faced by the construction of encircling port under the requirements of marine ecological civilization.Taking the Breakwater Project in Ganyu port area of Lianyungang port in the northernmost part of Jiangsu Province as an example,this paper studies the impact of the construction of the encircling breakwater on the marine environment ecology by using the mathematical model and the investigation data of hydrology,topography and marine environment ecology for many years before and after the construction of the breakwater,and then puts forward the ecological transformation scheme and ecological improvement measures of the encircling breakwater.The research is as follows:(1)The influence of breakwater construction on the marine hydrodynamic and siltation environment is mainly manifested in the decrease of velocity caused by water blocking at breakwater section and the increase of velocity caused by rippling at breakwater head on the east side,the siltation in port area and breakwater toe area on the west side near breakwater area on the east side,and the small degree of Scouring at breakwater head outside and on both sides of breakwater on the east side.(2)The half-exchange time of the water body in the harbor area has doubled after the completion of the encircling breakwater.However,according to the environmental measurement data,the average change trend of the water quality inside and outside the port area is basically the same,therefore,the weakening of the water exchange capacity has little impact on the water quality of the port area.The construction of the project has no significant impact on the quality of sediment environment,but it has a certain impact on the ecological environment.The content of chlorophyll-a,density and biomass of benthos in the harbor area always show a decreasing trend during the construction of the project.(3)The removal of breakwater can enhance the water exchange capacity,but it has no obvious effect on the improvement of marine environment.Moreover,the removal of breakwater will affect the berthing conditions of Ganyu port area and increase the siltation of harbor basin and channel,so the removal scheme is not feasible.(4)In order to repair the water environment of the port area,dredging can be carried out regularly to remove the pollution in the harbor area,and measures such as removing the breeding ponds,strengthening the construction of environmental protection infrastructure and carrying out tracking and monitoring can be taken to achieve the purpose of controlling the pollution sources in the harbor area.In order to repair the ecosystem in the harbor area,the harbor area is retired to the beach and vegetation planting to restore the beach ecosystem.For the restoration of aquatic ecosystem in the harbor pond,it is suggested to carry out augmentation and stocking to further improve the regional marine ecological environment.