绿华岛海底电缆敷设对海域内悬浮泥沙的影响

Study on influence of Luhua Island submarine cable laying project on suspended sediment of surrounding sea area

为了解舟山绿华岛电缆敷设过程所造成的悬浮泥沙对周围海域的影响,通过MIKE 21模型对绿华岛及其周围水域建立二维水动力及泥沙输运模型,再结合水动力情况模拟泥沙输运情况。模拟结果表明:泥沙随着潮流向周围扩散,且浓度不断降低。在涨急~涨憩阶段,悬沙主要影响东绿华岛北侧和花鸟岛南侧海域;在涨憩~落憩阶段,主要影响西绿华岛东侧和南侧海域;在落憩~涨急阶段,悬沙影响范围最大,为59.322 km 2,主要影响西绿华岛和花鸟岛西北侧海域。海底电缆敷设3 h后,海域悬沙浓度均低于150 mg/L,对周边海区悬沙浓度影响甚微,在涨急时刻悬沙对周围环境影响面积最小。

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 km 2,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.