【作者】 丁远静；

【导师】 王义刚； 徐建益；

【作者基本信息】 河海大学 ， 港口、海岸及近海工程， 2007， 硕士

【摘要】 为满足长江口航运、饮水、防洪排灌及岸线利用需求，近年来长江口治理工程的进度逐步加快，未来二十年内长江口河道将逐步束窄浚深，长江口河势将发生革命性的变化。本文分析了长江口的自然环境、水文条件及河势特征，探讨了二维潮流及盐度数值模型的建立方法，利用Delft3D建立了长江口杭州湾二维潮流及盐度模型，就拟建的众多围垦、潜堤及水库工程对长江口枯季产生的综合影响进行了数值计算，并从流量、流速、流向、水位和盐度四方面进行了探讨。研究表明工程实施对长江口涨落潮量的影响较大，枯季落潮量将减小17.4％，涨潮量将减小18.8％；北槽涨落潮分流比将增大，其余断面涨落潮量均减少；北支束窄工程将使其纳潮量减小，入口的落潮量增加，涨潮量减小，但北支入口涨潮量仍大于落潮量；口门地区对外海增水敏感性将增加，口内地区对外海增水敏感性将减小；工程实施后能有效抑制外海盐水的直接入侵，但对减小北支盐水倒灌南支的效果不明显。更多还原

【Abstract】 To meet the demand of navigation, fresh water supply, flood prevention, irrigation, drainage and longshore development, the progress of regulation projects in Changjiang Estuary goes faster and faster. The revolution of Changjiang Estuary will take place after projects in nearly 20 years.In this paper, natural environment, hydrological conditions and river regime characteristics are discussed. Methods for establishing tidal and salinity numerical model are studied. A 2D numerical model from Jiangyin to nearshore of Changjiang River was established by Delft3D. Comprehensive influence by multiple projects on flux, flow velocity and direction, water level and salinity was calculated.The results show that total flood volume will decrease 17.4%, and ebb volume will decrease 18.8% in dry season after regulation projects in the Estuary. Split ratio of the North Channel will increase, while other channels will decrease. The project to narrow the North Branch will reduce the storage capacity for tidal water. This will be benefit for ebb tidal volume increasing and flood tide decreasing at the mouth of North Branch. However, the flood tidal volume is still larger than that of ebb tide. Area at the mouth of Changjiang Estuary will become more sensitive of water rise up in open sea after projects. The projects can effectively suppress the direct saltwater intrusion, but ineffective to prevent saltwater intrusion from North Branch.更多还原