This study used a combination of Finite-Time Lyapunov Exponent (FTLE) values, residual currents, and tidal excursion lengths to systematically investigate the effects of tidal dispersion on oil spill trajectories in Burrard Inlet, BC, Canada, which is a tidally dominated estuary. The FTLE analysis results showed that tidal type and tidal phase significantly influenced the FTLE fields because the flow structure and the location of saddle points varied as a function of the tidal type and tidal phase. Some transport barriers formed in the Inner Harbour, which blocked the water exchange between the western and eastern parts of the inlet. Moreover, tidal mixing in the wider regions of Burrard Inlet (i.e., the western Outer Harbour) was relatively weak than in the narrower areas (i.e., First Narrows and Second Narrows). The observations from the FTLE analysis agreed well with the residual currents and tidal excursion results. The drifter trajectories were consistent with the Lagrangian coherent structure lines extracted from the FTLE analysis. To verify the tidal dispersion impact on an oil spill trajectory in the inlet, the FTLE fields were compared with a real oil spill that occurred in Burrard Inlet in 2015 (the M/V Marathassa oil spill). The FTLE fields reasonably explained the spilled oil’s trajectories from the real event. In addition, a set of stochastic oil spill models were run in this study and found that the FTLE analysis was a reliable tool for oil spill tracking. Overall, the FTLE method would be a valuable addition to practical oil spill response planning.

本研究结合了有限时间李雅普诺夫指数 (FTLE) 值、剩余电流和潮汐偏移长度，系统地研究了潮汐扩散对加拿大不列颠哥伦比亚省 Burrard Inlet 溢油轨迹的影响，该河口是潮汐主导的河口。FTLE分析结果表明，潮汐类型和潮相对FTLE场有显着影响，因为流动结构和鞍点位置随潮汐类型和潮相的变化而变化。内港形成了一些运输屏障，阻碍了入口西部和东部之间的水交换。此外，Burrard Inlet 较宽区域（即外港西部）的潮汐混合比较窄区域（即 First Narrows 和 Second Narrows）相对较弱。FTLE 分析的观察结果与剩余电流和潮汐偏移结果非常吻合。漂流物轨迹与从 FTLE 分析中提取的拉格朗日相干结构线一致。为了验证潮汐扩散对入口溢油轨迹的影响，将 FTLE 场与 2015 年发生在 Burrard Inlet 的真实溢油进行了比较（theM/V Marathassa漏油）。FTLE 场从真实事件中合理地解释了泄漏油的轨迹。此外，本研究运行了一组随机溢油模型，发现 FTLE 分析是一种可靠的溢油跟踪工具。总体而言，FTLE 方法将是对实际溢油响应计划的有价值的补充。