【作者】 李宁；

【导师】 张庆河； 毛志华；

【作者基本信息】 天津大学 ， 港口海岸及近海工程， 2009， 博士

【摘要】 海洋水质恶化和突发性海洋水质及生态灾害给人类生产和生活带来巨大隐患,造成大量经济损失。近年来,遥感技术因为能够大范围快速监测海面状况在海洋水质监测中愈益受到重视。数值模拟方法因为能够对各种海洋现象进行模拟并可以通过模拟结果分析揭示海洋现象的变化过程,在海洋环境与生态的研究中得到越来越广泛应用。遥感数据的获取受到天气条件等的影响,数据间隔受航测周期或卫星运行周期制约;数值模拟需要合理选择参数,合理确定边界条件、初始条件,模拟结果需要监测资料验证。将遥感与数值模拟相结合,可以使两种研究方法的不足得到互相弥补,对于近岸水质研究具有重要意义。为此,本文将遥感与数值模拟方法有机结合,应用于我国近岸水质和突发性海洋灾害的研究中。论文的主要研究内容和结论大致可以概括为以下两部分:第一部分,对杭州湾水质状况进行研究。首先,通过遥感技术对面源污染进行大面积监测,监测结果表明污染物主要受物理混合作用控制,表现出保守性特征,说明海洋动力过程对污染的传输和扩散起到了重要作用。为此,采用COHERENS模型中拉格朗日粒子传输方法和欧拉物质输运方法模拟面源污染物的扩散路径和水质更新时间,对其物理自净能力进行分析。其次,对杭州湾的点源热污染进行遥感监测,并开展两次实测调查,通过热扩散数值模型模拟秦山核电站温排水的分布特征,分析点源热污染对杭州湾的水质影响。最后,在对杭州湾的常规水质因子进行遥感监测和数值模拟的基础上,将温度和叶绿素浓度的数值模拟结果用于遥感数据补缺,使得遥感技术和数值模拟方法相互补充,在近岸常规水质研究中综合发挥作用。结果表明杭州湾点源热污染对水质影响并不严重;面源污染容易聚集在湾顶西北部和湾口东南部区域;湾内悬浮泥沙含量高、营养盐丰富、叶绿素浓度低,属于高营养盐低生产力的典型区域。第二部分,针对2008年青岛奥运基地附近海域爆发的浒苔藻华现象,将遥感监测和数值模拟相结合的方法进一步应用于突发性海洋灾害的研究中。首先采用遥感手段对藻华的发展过程进行跟踪监测,然后利用COHERENS生态-动力耦合模型模拟黄海春季浮游植物生长情况,并用拉格朗日粒子传输方法跟踪黄海中部浮游植物的漂移路径,最后采用一维生态-动力耦合模型模拟大风天气对藻类生长的影响。结果表明,黄海中部地区浮游植物首先进入繁盛期,但是直接传入青岛附近水域诱发藻华的可能不大,浒苔藻华之前青岛附近海域持续大风和降雨天气对浒苔的大量生长起到了促进作用。更多还原

【Abstract】 The deterioration of marine water quality and unexpected oceanic disaster often make trouble to production and life of human beings, and result in substantial economic losses. In recent years, remote sensing has attracted more and more attention by monitoring the sea surface conditions in large scale and in near real time. Numerical simualtion is widely used in marine environmental study due to its flexibility in simulating and analyzing the oceanic phenomena and changes. However, remote sensing is seriously influenced by the weather condition and limited by the aerial survey or satellite operation period. Numerical simulation is obstructed in attaining the optimal parameter, the reasonable boundary or initial condition and verifying data. Therefore, it is of great significance to combine remote sensing and numerical simulation together for overcoming one’s weaknesses by acquiring the strong points of the other. In this paper, these two methods are coordinated to study the water quality and unexpected oceanic disaster in the coastal areas. The following two parts are presented in this dissertation:The first part of this dissertation deals with the routine water quality in the Hangzhou Bay. Firstly, remote sensing monitoring results show that the distribution of area-source pollution in the bay is mainly controlled by the hydrodynamic factors. So, the pollutant trajectories and the half exchange time are simulated by the COHERENS model through Lagrangian particle tracking and Euler mass transport methods to analyze the physical self-purification capability in the bay. Secondly, the shipboard observation and numerical simulation combined with remote sensing are applied to study the warm water distribution and the influence of point-source thermal pollution on the water quality in the bay. Finally, the numerical SST (sea surface temperature) and chlorophyll-a results are used to make up the blank areas caused by cloud in the satellite images, which means that the mutual promotion of the remote sensing and numerical simulation play an important role on the coastal water quality study. It is shown that the point-source thermal pollution is not serious in the Hangzhou Bay. The area-source pollution is prone to accumulate in the northwest of the bay head area and the southeast of the bay mouth area. The bay is a typical high-nutrient-low- production place with high nutrient and suspended sediment concentration and low chlorophyll concentration. The second part of this dissertation deals with the unexpected oceanic disaster. The remote sensing and numerical simulation methods are applied to study the algal bloom in coastal area around Qindao City in 2008. Firstly, the development of the algal bloom is tracked by remote sensing. Then, the phytoplankton growth in spring in the Yellow Sea and the phytoplankton transportation from the middle part of the Yellow Sea are simulated by COHERENS ecological dynamics model and the Lagrangian particle track model. Lastly, the influence of wind on the algal growth is studied by the one-dimensional ecological dynamics model. The results imply that the phytoplankton blooms firstly in the central area of the Yellow Sea, while it is impossible to get the coastal area directly and induce the local algal bloom. The sustained wind before the algal bloom is helpful to the phytoplankton growth.更多还原