钦州湾典型工程溢油对周边海域影响的数值模拟研究

Numerical Simulation Research on the Effect of Oil Spill from Typical Engineering on the Surrounding Waters in Qinzhou Bay

广西龙门大桥作为滨海公路,是北部湾区域经济的控制性工程,存在一定的溢油风险。本研究基于FVCOM模型分析钦州湾的潮流特征,通过溢油模型对无风、全年最大概率常风和极值风等3种风况情景下的油膜漂移扩散特征和归宿行为进行研究。结果表明,钦州湾潮流主要为往复流,龙门水道最大流速可达1.8 m/s。风速、风向和发生时刻对油膜厚度、残油量、最大扩散距离和扫海面积有重要作用:风速越大,溢油蒸发速度越快;同等风速下,72 h后北向风的油膜厚度和残油量大于南向风,而高潮时发生溢油72 h后油膜的最大扩散距离比低潮时大。涨潮期间,极值风风况情景下油粒子到达广西茅尾海红树林自治区级自然保护区坚心围片;落潮期间,油粒子扩散至钦州港青菜头南浅海滩涂养殖区。研究结果为提升溢油预警预测能力、降低溢油造成的损失提供了理论基础。

As a coastal road,Guangxi Longmen Bridge is a control project of Beibu Gulf regional economy,and there is a certain risk of oil spill.In this study,based on the FVCOM model,the tidal current characteristics of Qinzhou Bay are analyzed.The oil spill model is used to study the oil film drift and diffusion characteristics and fate behavior under three wind conditions:no wind,annual maximum probability normal wind and extreme wind.The results show that the tidal current in Qinzhou Bay is mainly reversing current,and the maximum velocity of the Longmen channel can reach 1.8 m/s.Wind speed,wind direction and occurrence time play an important role in oil film thickness,residual oil,maximum diffusion distance and sweeping area.The greater the wind speed,the faster the evaporation rate of spilled oil.Under the same wind speed,the oil film thickness and residual oil amount of the north wind are greater than those of the south wind after 72 h,the maximum diffusion distance of the oil film after 72 h of oil spill at high tide is larger than that at low tide.During the flood tide,the oil particles reach the core enclosure of Maowei Sea Mangrove Nature Reserve in Guangxi under the extreme wind condition.During the ebb tide,the oil particles spread to the aquaculture area of Qingcaitou South Shallow Beach in Qinzhou Port.The research results provide a theoretical basis for improving the early warning and prediction ability of oil spill and reducing the loss caused by oil spill.