【作者】 陈媛媛；

【导师】 高学平；

【作者基本信息】 天津大学 ， 水力学及河流动力学， 2013， 博士

【摘要】 近年来，随着城市现代化的发展和人们生活水平的不断提高，水景观逐渐融入了人们的生活，城市滨水区景观开发逐渐成为了一个新的热点。而现阶段的滨水区景观设计过程中，往往对水环境问题认识程度不够，同时缺乏系统的理论作为依据，为景观水体的长期运行和管理埋下了隐患。一些水环境问题也随之而来，主要体现在水质，水体交换能力等问题。在一个水环境系统中，水体物理和生物化学过程相互影响，控制污染物的归宿，对生态系统的健康与否起着重要的作用。其中，一个重要的物理过程即为水体与外界的水体交换，污染物通过对流输运和稀释扩散等物理过程与周围水体混合，与外海水交换，浓度降低，水质得到改善。因此，在研究水景观的环境问题之前，定量的研究水体交换能力和污染物扩散规律至关重要。本论文以一景观型泻湖（七里海泻湖）为背景，建立七里海泻湖的三维水动力数学模型，根据现场观测数据进行了泻湖校核与验证；并利用更新时间、停留时间、曝光时间、连通性等方法研究七里海泻湖的水体交换能力及污染物的输移扩散规律。主要研究内容及成果如下：（1）全面介绍了三维环境流体力学模型EFDC，并基于EFDC模型，建立了七里海泻湖数值模型，共包括现状七里海泻湖模型网格和修复后七里海泻湖模型网格两套网格，前者用于模型验证，后者用于修复后泻湖的水动力学模拟。给出了七里海泻湖水动力模型的主要参数设置，并利用辽东湾两个测站的两组实测数据对模型的计算结果进行校核与验证。证明了本模型模拟七里海泻湖水动力特性的有效性和实用性。（2）应用修复后七里海泻湖数学模型研究了七里海泻湖的流场特性，模型全面考虑海洋潮汐，季节性风对七里海泻湖的流场的影响，通过这些模拟增进对海洋中近似保守物质输移过程的理解。（3）应用修复后七里海泻湖数学模型研究了七里海泻湖的水体交换特性，选用更新时间、停留时间、曝光时间等方法分析水流输运时间，通过数值模拟试验，分析了海洋潮汐、季节性风、潮汐通道口深度与数目对七里海泻湖的水流输运时间的影响，增进了对泻湖中物质的输运过程及它们在时间、空间上变化过程的认识。（4）应用修复后七里海泻湖数学模型研究了七里海泻湖的污染物扩散规律，选用连通性等方法分析泻湖内污染的扩散规律，通过数值模拟试验，分析了海洋潮汐、季节性风、潮汐通道口深度与数目对污染物扩散规律的影响，便于管理者及时确定污染源的影响范围、影响时间，为泻湖的水质管理提供科学支持。更多还原

【Abstract】 In recent years, the development of water landscape is becoming a new hotspotgradually with the improvement of city modernization and the people’s livingstandard. During the process of the waterfront district landscape design, the designersoften lack of full attention to the water environment problems and lack of systemtheory knowledge, so that some water environment problems (poor hydrodynamic,deteriorated water quality et al) will be emerged during long term operation of waterlandscape. The health of a water ecosystem is governed by its physical, chemical, andbiological processes. One physical process that affects the health and water quality ofthe system and indicates its susceptibility to impairment is water renewal capacitybetween the lagoon and the open sea. Through the advection and diffusionmechanisms, the water mass is transported to the open sea where it is mixed with thesea. During this process, the pollutant is neutralized and mechanically removed fromthe ecological compartment.So it is important to study on water renewal capacity andthe transport and diffusion processes of pollutants for a landscape ecosystem system.In the study, we take a landscape lagoon as an example, to study the transport anddiffusion process in a reconstructed lagoon (Qilihai Lagoon) using residence time,exposure time using a three-dimensional numerical model. The model was calibratedand verified by using field measured data. The main works of this study are asfollows:(1) A three-dimensional numerical model-Environmental Fluid Dynamics Code（EFDC）was introduced in detail. The case of the Qilihai Lagoon was proposedbased on EFDC in this study and two structured grids were used to model it. One gridrepresented the present configuration of the lagoon and was applied for modelcalibration and validation. The other grid represented the configuration of the lagoonafter reconstruction and was used for studying the water renewal capacity in thereconstructed lagoon. The Qilihai Lagoon model was calibrated and verified by usingfield data measured, and the main parameters about the model was confirmed. Theresults showed that the model could accurately and effectively simulate hydrodynamicconditions in the lagoon.(2) The the reconstructed lagoon model was used to study the flow field in thelagoon. The influences of wind on flow field were also investigated. It would help usto understand the transport and diffusion processes of conservative substances. (3) The the reconstructed lagoon model was used to study the water renewalcapacity in the lagoon. The renewal time, residence time and exposure time were usedas timescales. The influences of wind and the depth and the number of the tidal inletof the lagoon on water renewal capacity were also investigated. It would help us tounderstand the spatial and temporal distribution the transport and diffusion ofconservative substances in the lagoon.(4) The the reconstructed lagoon model was used to study the transport anddiffusion processes of pollutants in the lagoon. The connectivity were used astimescales. The influences of wind and the depth and the number of the tidal inlet ofthe lagoon on transport and diffusion processes of pollutants were also investigated. Itwould help manager control the pollution and manage the water quality scientifically.更多还原