围填海工程对天津近海水动力环境的影响研究

发布时间：2018-03-31 18:03

本文选题：渤海湾　切入点：围填海　出处：《上海海洋大学》2017年硕士论文

【摘要】：当前沿海城市发展迅速,无论是经济还是科技都处于领先地位,这就吸引了大量的人口向沿海城市的涌入,求学或者工作以至于定居,沿海地区带来各项进步的同时也给其造成了很大的压力,于是人类想到了一个向海借地的好方法——填海造陆,不仅能够解决当前日益增长的用地矛盾,而且能够很好的利用资源,与此同时,很多由于填海造陆造成的负面影响也悄然而至,这些引起了许多专家学者的关注。本文以渤海湾为研究对象,主要分析天津近海海域,针对天津近海围填海工程对其附近海域的潮流、潮汐以及纳潮量和水交换的影响展开研究,在此过程中针对潮汐、潮流进行了实地的观测,通过对观测结果的分析,发现在天津近海围填海工程附近水域的观测点这两项要素的形态差别较大,为了能够更加清晰的认知围填海工程带来的影响,本文利用数值模拟方法进行研究。针对渤海湾及其附近海域显著地特点:岸线复杂弯曲、分布不均匀的较大滩涂面积和形态复杂的海底底地形,本文选择利用三维水动力模型——FVCOM进行模拟研究,该数值模型具有以下优点:三角形网格、有限体积法、干湿边界处理方法,这些优点可以很好地解决渤海湾模拟的问题。选择好模型之后利用实测数据对模型进行验证,得到可靠结果之后,能够利用该模型进行接下来的研究。本文选取了三个典型的历史时期,2005年、2010年、2015年进行研究,2005年之前天津近海并未进行大规模围填海工程,2015年围填海工程基本完成,三个时期岸线变化较大,因此选取这几个典型时期研究更能准确的展示天津近海水动力环境在不同岸线条件下的变化。对模拟结果研究分析得到围填海工程改变了天津近海潮汐特征,各分潮从外海向渤海湾内传播,至天津近岸处振幅最大,迟角自北向南逐渐变大,至岸边等迟角线基本与岸线垂直;对天津沿海潮流特征的影响较为复杂。主要是因为海岸工程大量建设,岸线复杂,尤其是近岸工程附近潮流主要依岸线流动。涨落潮期间,南部海域为西南-东北走向往复流,北部沿海涨落潮流向为东南-西北向往复流。余流以沿岸流为主,余流受岸线影响十分显著,流向变化复杂;围填海工程是的天津近海纳潮量的明显减小。从2005年开始至2015年,纳潮量的整体趋势呈现逐年递减的趋势,至2020年众多围填海工程建成后,纳潮量对围填海工程的响应较为显著;围填海工程对海域水交换的影响显著,使得污染物扩散缓慢,给海域的水环境造成了较大压力,并且具有一定的影响。通过分析得出相比2005年,采用2015年状况下的渤海湾水交换率明显下降。水交换率的下降,随时间的延长有逐渐增大的趋势,下降的水交换率将延长污染物扩散时间,使渤海湾原本就困难的扩散能力更加降低,使原本就恶劣的海洋环境更加恶化。同时对功能区划中围填海工程可能对渤海湾水交换能力造成的影响进行了预测。在2020年功能区划围填海计划完成的状态下,半交换周期需408天,比2015年情况下的延长10天,同时水交换率也有明显的下降。通过以上研究分析结果,可以预测在未来围填海工程下天津近岸水动力环境的变化,从而更加科学深入的认识到海洋环境要素对围填海工程累积效应的响应,对于科学合理开发海岸带资源,保护海岸带生态环境具有重要经济效益和社会效益。
[Abstract]:The coastal city of the rapid development of both the economy and science and technology are in the leading position, which attracted a large influx of population to the coastal city, study or work that settle in coastal areas, bring the progress but also to which caused a lot of pressure on the human thought of a loan to the sea of good methods: land reclamation, land can not only solve the contradiction of the current growing, but also very good use of resources, at the same time, because of the many negative effects caused by sea reclamation also quietly, which attracted many scholars attention. In this paper, the Gulf of Bohai as the research object, the main analysis of the coastal waters of Tianjin, in Tianjin the trend of reclamation on the surrounding coastal waters near the study effect of tide and tidal volume and water exchange, in the process for the tide, tide in the field Observation, through the analysis of the observation results, found in Tianjin coastal waters near Wai reclamation observation point of morphological differences between these two elements is large, in order to effect a more clear cognition of the sea reclamation project, this paper studied by numerical simulation method. For the waters of the Gulf of Bohai and its significant characteristics: complex near the shoreline bending, the uneven distribution of large tidal flats and complex patterns of seafloor topography, this paper simulated by three-dimensional hydrodynamic model -- FVCOM, the numerical model has the following advantages: triangular mesh, finite volume method, the wet dry boundary processing method, these advantages can solve the problem. After the simulation in Bohai Bay choose a good model using measured data to verify the model, then get a reliable result, can carry out the following research by using the model. We select three A typical historical period, 2005, 2010, 2015, 2005 before Tianjin offshore has not carried out a large-scale reclamation, land reclamation projects completed in 2015, three periods of shoreline changes greatly, so this study selects several typical period more accurately show the Tianjin water power environment in different shoreline conditions change. The simulation results of research results of sea reclamation changed Tianjin offshore tidal characteristics, the tide from the sea to spread to Tianjin in the Gulf of Bohai, near the shore of maximum amplitude, angle from the north to the South gradually, to the shore line and shoreline vertical angle; impact on Tianjin coastal tidal current characteristics are more complex. Because a lot of construction of coastal engineering, coastal complex, especially near the main trend in offshore engineering. During the ebb flow of coastline, the southern waters to the southwest - northeast direction to The complex flow, the northern coastal tidal current to southeast northwest for reflow. The residual current in the coastal current, the residual current by the shoreline influence to complex changes; decrease the reclamation is the tidal volume. Tianjin Haina started from 2005 to 2015, the overall trend of tidal volume is decreasing year by year the trend, to 2020 many reclamation project is completed, the response to tidal volume of the sea reclamation project is significant; effects of the reclamation of sea water exchange significantly, making the diffusion of pollutants is slow, resulting in greater pressure to the sea water environment, and has a certain influence. Through analysis that compared to 2005, by 2015 under the condition of the water exchange in Bohai Bay was significantly decreased. The water exchange rate decline, gradually increased along with the prolongation of time, decrease the rate of water exchange will extend the pollutant diffusion time, the Bohai Bay was trapped The more difficult to reduce the diffusion ability, which had a bad effect on the deterioration of the marine environment. At the same time in the planning of reclamation project may result in Bohai bay water exchange capacity were predicted in 2020. The reclamation function zoning plans to complete the state, half exchange period for 408 days, than in 2015 under the condition of extension the 10 day, while water exchange rates have decreased significantly. Through the above research results can predict changes in the future reclamation projects under the Tianjin nearshore hydrodynamic environment, thus more scientific understanding to the marine environment of the reclamation project in response to the cumulative effects of resources for scientific and rational development of coastal zone, ecological environment the protection of the coastal zone has important economic and social benefits.

【学位授予单位】：上海海洋大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P756.8;P731.2

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