Numerical Study Of The Impact Of Water Environment By Artificial Island In The Gulf

This paper, with background of Dalian Bay, use related modules of MIKE21 to simulate the tidal current field and the spread of pollutants in Dalian Bay before and after artificial island embedded, and then study the impact of water environment by artificial island in the gulf.Firstly, the paper complete the tidal current field verification of Dalian Bay, and then simulate the tidal current field of Dalian Bay with artificial island embedded, and finally based on three aspects, circulation flow, flow velocity and the trajectory of water quality point, the paper study the impact of flow field by artificial island in the gulf. The study indicates that after embedded artificial island, circulation flow is formed obviously in Dalian Bay; the max flow velocity at entrance of the bay of neap tide and spring tide will happen on the left of entrance of Dalian Bay, and velocity and direction of flow will change, and under most of artificial island conditions, the max flow velocity is larger than that of without artificial island condition; the site of the trajectory of water quality point moving out of the bay will change from the right of the entrance of the bay without artificial island embedded to the left of it.Under the concept of water exchange, the paper study the impact of water environment by artificial island in the gulf, which was finished by way of studying three directions of water exchange indicators, containing the tidal flux, tidal volume and pollutants retention rate. After the artificial island embedded in the gulf, the tidal flux increases monotonically with the length and width of island decreasing; the tidal volume was described by tide level gap, and the curve of process of change between tide level gap and width of island is more satisfied than that with length, and the tide level gap decreases monotonically with the width of island decreasing; the curves of process of change between pollutant retention rate and length of island develop by a similar way, but not develop as linear change, as when the length of islands are 11/11L, pollutant retention rate will drop as a sudden, which can be very helpful to search for a large area island with low pollutant retention rate.Finally, tide level gap and pollutant retention rate respectively set as the primary water exchange index, combining the actual function of artificial island, and the artificial island programs compared, the paper recommended a number of meaningful planning programs.