关键词: 悬浮泥沙; 海洋环境影响; 数值模拟; MIKE 21; 海底电缆; 绿华岛;

Abstract: In order to analyze the influence of suspended sediment on the surrounding sea area caused by the cable laying process at Luhua Island in Zhoushan City, a two-dimensional hydrodynamic and sediment transport model was established by MIKE 21 for Luhua Island and its surrounding sea area, and then sediment transport was simulated with the combination of hydrodynamic conditions.The simulation results showed that the sediment spread to the surrounding area with the tidal current, and sediment concentration decreased continuously.The suspended sediment mainly affected the north side of Dongluhua Island and the south side of Huabird Island during the spring tide to flood slack period.During the flood slack to ebb slack period, suspended sediment mainly affected the eastern and southern sea area of Xiluhua Island.During the ebb slack to spring tide period, the influence range of suspended sediment was the largest, which was 59.322 km2,mainly affecting the northwest sea area of Xiluhua Island and Huabird Island.After laying submarine cables for 3 h, the suspended sediment concentration in the sea area was less than 150 mg/L,which had little effect on the ecological environment in the surrounding sea area, and the impact area on the surrounding environment was the smallest in the spring tide period.

Key words: suspended sediment; marine environmental impact; numerical simulation; MIKE 21; submarine cable; Luhua Island;