舟山复杂海岛条件下某交通码头溢油环境风险评估

Environmental Risk Assessment of Oil Spill in A Transport Terminal under Complex Island Conditions in Zhoushan

考虑到舟山海上运输业发达,一旦有溢油事故发生,会对周围海域水环境造成严重危害。为进一步了解舟山群岛范围内溢油风险影响,文中以舟山定海某交通码头工程为研究对象,建立工程区域二维水动力模型并对潮位和潮流进行验证。同时,针对码头前沿和航道处在不利风向和潮流因素的组合工况下,耦合“油粒子”模型对复杂海岛条件下溢油风险的影响进行预测分析。结果表明:(1)受岛屿狭道效应,初期潮流作用影响明显。码头前沿和航道处溢油会沿涨落潮流方向进行漂移,受不利风向SE的进一步作用,码头前沿涨潮阶段会朝着杭州湾方向漂移扩散,而码头前沿落潮阶段和航道处涨落潮阶段均向西北-东南方向震荡漂移。(2)群岛内岛屿众多,分别对码头前沿和航道处的涨落潮时刻油粒子漂移轨迹产生阻碍作用,导致油粒子漂移动力产生部分削弱,从而减小油膜影响面积。(3)数值结果表明航道处涨潮时段发生溢油风险危害最大,其油膜最大扫海面积达到1442.3 km^(2)。涨落时刻,溢油到达敏感区域时间存在明显差异,在6~7 h之间。

Considering the development of zhoushan maritime transport industry,oil spill accidents will cause serious harm to the surrounding sea water environment.In order to further understand the influence of oil spill risk in Zhoushan Archipelago,a two-dimensional hydrodynamic model of a traffic wharf project in Dinghai of Zhoushan is established and verified.Meanwhile,the influence of coupling′oil particle′model on oil spill risk under complex island conditions is analyzed under the combination of unfavorable wind direction and tidal current in the wharf front and waterway.The analysis results show that:(1)With the island narrow channel effect,the initial tidal current effect is obvious.The oil spill at the wharf front and the channel will drift along the direction of the fluctuation trend.Due to the further effect of the adverse wind direction SE,the tidal stage at the wharf front will drift and spread in the direction of Hangzhou Bay,while the tidal stage at the wharf front and the fluctuation stage at the channel will both drift in the northwest-southeast direction.(2)There are many islands in the archipelago,which hinder the oil particle drift trajectory at the wharf front and the channel at the fluctuation tide,respectively,resulting in the partial weakening of the oil particle drift force,thereby reducing the oil film influence area.(3)The numerical prediction results show that the oil spill risk is the most harmful during high tide in the waterway,and the maximum sea swept area of oil film reaches 1442.3 km^(2).At the time of fluctuation,the time for oil spill to reach the sensitive area is significantly different between 6 and 7 hours.