基于欧拉-拉格朗日方法的某溢油事故天然渔业资源损失评估方法案例研究

本研究针对渤海中部某船舶碰撞溢油事故，基于欧拉-拉格朗日方法，对事故发生后的油膜漂移扩散和油膜消失后的溶解态分布趋势，分别进行了数值模拟。在此基础上，界定事故溢油对渤海天然渔业资源的影响范围，进而估算天然渔业资源损失。结果显示：溢油量按13 m3计算，油膜存在期约为72 h，累加油膜扫海面积约为69.19 km2；油膜消失后，事故溢油仍会以溶解态、乳化态或悬浮颗粒态在海水中扩散，水体中的石油烃含量符合渔业水质标准，溢油在第11天中午即可抵岸；油膜会造成渔业资源损失，油膜消失后，悬浮颗粒态和乳化态石油在岸滩等因素影响下会形成凝聚态石油，并对潮间带生物造成影响。其影响面积结合溶解态抵岸区域内自然岸线长度予以估算，经评估，在油膜扫海区域及受影响潮间带范围内，事故经济损失额合计为631.9万元。本研究对数值模型方法在溢油事故天然渔业资源损失评估中的应用方面做了有益尝试，为无现场观测数据支撑的海洋溢油事故天然渔业资源损失评估提供了一个可行的方法。

Evaluation of the Natural Fishery Resources Loss Caused by an Oil Spill Accident in the Central Bohai Sea Based on Euler-Lagrange Method

In recent years, marine oil spill accidents occurred frequently, which has become a major concern on the marine environment and biological resources. To better understand the aftermath of an oil spill in a ship collision accident in the central Bohai Sea, here we modeled the floating and diffusion of oil film as well as the distribution of dissolved oil (petroleum hydrocarbon) using Euler-Lagrange method. The size of affected area and loss of fishery resources were also evaluated based on this model. We found that the volume of spilled oil was about 13,000 L, and the oil film lasted for 72 hours. The sea area affected by accumulated floating oil was about 69.19 km2. As the film broke down, oil droplets could be dissolved in the seawater in the form of emulsified and suspended particulate, and diffused to the coastal in 11 days, although the water quality would still meet the standard for fisheries. The oil film resulted in reduced fisheries resources, and the emulsified and suspended particulate could re-condense at the coast, which would harm the intertidal benthos. The affected area was determined based on the model and the length of coastline. It was estimated that the total economic loss in the oil film zone and the intertidal coastal zone was ¥ 6.319 million. Our study demonstrated that the numerical model, especially in the absence of observed data, could be a valuable tool in evaluating the change in natural fishery resources caused by oil spill accidents.