中文摘要：

首先建立了一套基于非结构网格的长江口—杭州湾二维垂向平均潮流数学模型,又基于最新的实测资料重点对南支水域流速、流向和水位进行验证,充分证实了模型的可靠性。在潮流模型可靠的基础上为MIKE21SA（溢油模块）提供水动力基础数据,建立了一套基于欧拉-拉格朗日体系的＂油粒子＂追踪技术,综合考虑油膜扩展、输移和风化过程的长江口溢油行为与归宿预测模型。并对长江口夏季和冬季大潮溢油事故发生后取水口油膜厚度的变化及油膜运动路径进行了模拟预测。研究表明：油膜在长江口受到往复流形式的涨落潮交替作用,油膜沿深槽向下游震荡漂移;油膜在纵向上逐渐被拉伸,形成窄长的油带,覆盖面积逐渐增大;油膜的运动轨迹除了受到涨落潮流的主控外还易受风况和长江口水下地形等影响;夏季溢油对3个水库均有不同程度的影响,冬季溢油只威胁到陈行水库的取水;夏季油膜蒸发量大于冬季。

英文摘要：

Changjiang Estuary is abundant in natual resource and has an obvious locational advantage,which make Changjiang Estuary an economic development frontier of Changjiang basin and even of the whole na- tion. The development of the city needs a lot of high quality raw water. Nowadays, 70 ~ of the water supply in Shanghai is from Changjiang Estuary. Changjiang Estuary is leading waterway of Changjiang basin, which is developed in shipping and convenient in transportation. With the increase of ships affd boats in the sea area, it also results in an increase of collision incident and oil spill. Once the oil spill occurs, it will seri- ously affect the environment of Changjiang Estuary,the ecological environment and biodiversity of the sea area,as well as the water supply safety of Shanghai. So it is quite important to react at the very moment and take action properly as soon as the the oil spill occurs. First of all, based on the flexible mesh, a vertical 2-D numerical model for average tidal flow of Changjiang Estuary and Hangzhou Bay was proposed in the paper. With a huge amount of validation of hydrodynamic force in Changjiang Estuary,the model was also vertified by the lastest observation data mainly conducted in the South Branch area. The data mainly includ- ed flow velocity, flow direction and water level. Secondly, the Spill Analysis （SA）Model of MIKE21 was provided with basic hydrodynamic data after the reliability of tidal flow model proved. Based on an oil spill particle trajectory with the system of Eulerian-Lagrangian,a prediction model was established,which took the oil spill behavior including spread, transport and weathering as well as the end-result of oil spill in Changjiang Estuary into consideration. Finally, the model was used to simulate and predict the change of oil slick thickness and its spread path near the water intakings after the oil spill accidents of both the summer and winter spring tide in Changjiang estuary. The results shows that, affected by the alternative flood tide and ebb tide