长江河口内溢油轨迹的数值模拟研究

构建了海洋与溢油模型相耦合的长江河口的溢油轨迹预报系统,海洋模型能较好模拟该海域的表层流场;溢油模型采用拉格朗日和随机游走的油粒子追踪法,可快速预测油粒子的漂移扩散轨迹和扫海面积。研究表明,大潮时溢油的油粒子的分布范围和扫海面积均比小潮时刻大,在南支溢出的油粒子会漂移到南、北港和南、北槽,对生态环境危害最大,会影响陈行和青草沙两大水库取水口,并对中华鲟和九段沙湿地保护区产生潜在的生态危害;在北支溢出的油粒子主要分布在北支水道和两岸,如果溢油点位于上段会倒灌进南支水道,将会产生较大的生态危害;在南港溢出的油粒子会漂移到南北槽,不会对两大水库和中华鲟保护区产生危害,但会对九段沙保护区造成潜在的危害;在北港溢出的油粒子则会漂移到崇明岛外海,且扩散范围很大,只对中华鲟保护区造成危害。

Numerical simulation of oil spill trajectory in Yangtze River estuary

In this paper, coupling ocean and oil spill model, an oil spill trajectory forecast model for Yangtze Estuary was developed. The ocean model can better simulate the sea surface current field. Oil spill model by using oil particles tracking method of random walk and Lagrange, can quickly predict the drift trajectory and swept area of oil particles. Result shows that oil particle distribution and sweep areas in spring tide are bigger than in neap tide. Spilled oil particles in the south branch would drift to south, north channel and south, north passage. The biggest harms to ecological environment, will affect water intake of Chenhang and Qingchaosha reservoirs, and has potential ecological harm to the Chinese sturgeon and Jiuduansha wetland reserve; Spilled oil particles in the north branch are mainly distributed in the north branch channel and both shores. if oil spill spot is on upper north branch, oil particles would flow backward into the south branch channel, will has a large harm to ecology; spilled oil particles in south channel would drift to the north and south passage, not has harm to two reservoirs and Chinese sturgeon reserve, but will has potential harm to Jiuduansha reserves; Spilled oil particles in the north channel would drift to Chongming island out sea, and diffusion range is very large, only harm to the Chinese sturgeon reserve.