广西北部湾风暴潮的数值模拟
发布时间：2018-11-19 17:07
【摘要】：风暴潮灾害是广西沿海主要的海洋灾害,由于地处北部湾湾顶,独特的地理特征使得广西风暴潮不同于我国其他海岸风暴潮。通过数值模拟对风暴潮对北部湾的风暴潮进行研究,有助于加深对北部湾风暴潮地域特点及其动力机制的理解。本文利用广西沿海部分气象站2012年13次台风“启德”过境期间的风速风向观测资料,反演建立了一个合理的理想台风风场;同时建立了一个模拟结果良好的北部湾的FVCOM潮汐模型。在此基础上建立了广西北部湾FVCOM风暴潮-潮汐耦合模型,对1213次“启德”台风风暴潮进行了纯风暴潮以及风暴潮-潮汐耦合的模拟,并利用水位资料对其进行验证。1213次台风风暴潮模拟结果显示:本次台风主要作用于北部湾北部海区,主要增减水区域为广西沿海以及越南北部沿海,台风过程对于水体的“搅拌”作用可影响至全湾,但在北部海区余流响应更明显,底层海水也受到剧烈的影响。海湾增减水分布以及流场分布与台风风场结构以及路径特点相对应。本文也利用北部湾FVCOM风暴潮模型对北部湾风暴潮进行了理想风场实验,以论证广西北部湾风暴增水强度与入侵热带气旋路径,移速,强度之间的关系,结果表明:西北行热带气旋对北部湾作用时间较短,气旋过后北部湾风向迅速由稳定东北风变为稳定的西南风,风向与海湾轴线一致,有利于海水在湾顶集聚,并且由于移动方向为西北方向,使得西风,南风加强,加强的南风使得风暴增水进一步加强。西行热带气旋对北部湾作用时间较长,并且北部湾长时间是处于台风上或者台风下,受到南北风的同时影响,海区增减水不一致,海水难以大规模迅速集聚形成较高的风暴增水,增水幅度小,扰动多。北部湾风暴增减水大小与风暴移速大小之间并不存在简单的相关关系:一方面,随着气旋移速变大,气旋风场在气旋移动方向上的分量增加,这可能有利于风暴增减水;另一方面,气旋移速变大,其影响北部湾时间较短,风时较短又不利于风暴增减水的增加;同时随着风暴移速变化,风暴潮过程波动周期发生变化,风暴潮潮位波动与海岸回潮波之间波波相互作用也发生变化,实际潮位也会随之发生变化。台风强度的加强会加强风暴增水振幅,并不影响风暴潮频率。各站点增减水的差异也体现了北部湾地形对于风暴潮的影响,总体上表现为海湾增水强,开阔海岸增水较弱,海区增水最小的趋势。同时北部湾海湾狭长封闭的地理特征,也导致了海湾回潮波的影响较为明显,北部湾风暴增水曲线表现出余振时间长,主振扰动多的特点。
[Abstract]:Storm surge is the main marine disaster along the coast of Guangxi. Because it is located at the top of Beibu Bay, the storm surge in Guangxi is different from other coastal storm surges in China because of its unique geographical features. The study of storm surge in Beibu Gulf by numerical simulation is helpful to understand the regional characteristics and dynamic mechanism of storm surge in Beibu Gulf. Based on the observation data of wind speed and wind direction during the 13 Typhoon Qide transit in 2012, a reasonable ideal typhoon wind field has been established in this paper. At the same time, a FVCOM tidal model of Beibu Gulf with good simulation results is established. On the basis of this, the coupling model of FVCOM storm surge and tide in Beibu Gulf of Guangxi is established. The pure storm surge and the coupling between storm surge and tide are simulated for 1213 typhoon storm surges in Qide, Guangxi. The simulation results of 1213 typhoon storm surges show that the typhoon mainly acts on the northern sea area of Beibu Gulf, and the main areas of increasing and decreasing water are Guangxi coast and the northern coast of Vietnam. The "stirring" effect of typhoon on the water body can be affected to the whole bay, but the response of residual current in the northern sea area is more obvious, and the bottom seawater is also strongly affected. The distribution of increasing and decreasing water in the bay and the distribution of current field correspond to the structure of typhoon wind field and the characteristics of typhoon track. In this paper, the ideal wind field experiment of storm surge in Beibu Gulf is also carried out by using the FVCOM storm surge model in the Beibu Gulf, in order to demonstrate the relationship between the water increasing intensity of the storm and the track, velocity and intensity of the tropical cyclone invading in the Beibu Gulf of Guangxi. The results show that the northwestbound tropical cyclone acts on the Beibu Gulf for a short time. After the cyclone, the wind direction of the Beibu Gulf changes rapidly from a stable northeast wind to a stable southwest wind, and the wind direction is consistent with the Gulf axis, which is conducive to the concentration of sea water at the top of the bay. And because the direction of movement is northwest, the westerly and southerly winds are strengthened, and the strengthened south wind makes the storm increase water further. The westbound tropical cyclone acts on the Beibu Gulf for a long time, and the Beibu Gulf is on or under the typhoon for a long time, affected by the north and south winds simultaneously, and the increase and decrease of water in the sea area are not consistent. It is difficult for sea water to gather rapidly in a large scale to form a higher storm water increase, with small increase range and more disturbance. There is not a simple correlation between the increase and decrease of storm water and the speed of storm movement in Beibu Gulf. On the one hand, with the increase of cyclone velocity, the component of cyclone field increases in the direction of cyclone movement, which may be beneficial to the increase and decrease of storm water. On the other hand, the speed of cyclone moving becomes larger, which affects the Beibu Gulf for a short time, and the shorter wind time is not conducive to the increase of storm water supply. At the same time, with the change of storm velocity, the fluctuation period of storm surge process changes, the interaction between storm surge level fluctuation and coastal backtide wave also changes, and the actual tide level also changes. The increase of typhoon intensity will increase the amplitude of storm water, and will not affect the frequency of storm surge. The difference of increasing and decreasing water at different stations also reflects the influence of the topography of Beibu Gulf on storm surge. The general trend is that the increase of water in the bay is strong, the increase in water in the open coast is weak, and the increase in water in the sea area is the least. At the same time, the geographical characteristics of the narrow and narrow gulf of Beibu Gulf also lead to the obvious influence of the backtide waves in the Gulf. The water increasing curve of the Beibu Gulf Storm shows the characteristics of Yu Zhen long time and many main vibration disturbances.
【学位授予单位】：上海海洋大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P731.23
本文编号：2342905
[Abstract]:Storm surge is the main marine disaster along the coast of Guangxi. Because it is located at the top of Beibu Bay, the storm surge in Guangxi is different from other coastal storm surges in China because of its unique geographical features. The study of storm surge in Beibu Gulf by numerical simulation is helpful to understand the regional characteristics and dynamic mechanism of storm surge in Beibu Gulf. Based on the observation data of wind speed and wind direction during the 13 Typhoon Qide transit in 2012, a reasonable ideal typhoon wind field has been established in this paper. At the same time, a FVCOM tidal model of Beibu Gulf with good simulation results is established. On the basis of this, the coupling model of FVCOM storm surge and tide in Beibu Gulf of Guangxi is established. The pure storm surge and the coupling between storm surge and tide are simulated for 1213 typhoon storm surges in Qide, Guangxi. The simulation results of 1213 typhoon storm surges show that the typhoon mainly acts on the northern sea area of Beibu Gulf, and the main areas of increasing and decreasing water are Guangxi coast and the northern coast of Vietnam. The "stirring" effect of typhoon on the water body can be affected to the whole bay, but the response of residual current in the northern sea area is more obvious, and the bottom seawater is also strongly affected. The distribution of increasing and decreasing water in the bay and the distribution of current field correspond to the structure of typhoon wind field and the characteristics of typhoon track. In this paper, the ideal wind field experiment of storm surge in Beibu Gulf is also carried out by using the FVCOM storm surge model in the Beibu Gulf, in order to demonstrate the relationship between the water increasing intensity of the storm and the track, velocity and intensity of the tropical cyclone invading in the Beibu Gulf of Guangxi. The results show that the northwestbound tropical cyclone acts on the Beibu Gulf for a short time. After the cyclone, the wind direction of the Beibu Gulf changes rapidly from a stable northeast wind to a stable southwest wind, and the wind direction is consistent with the Gulf axis, which is conducive to the concentration of sea water at the top of the bay. And because the direction of movement is northwest, the westerly and southerly winds are strengthened, and the strengthened south wind makes the storm increase water further. The westbound tropical cyclone acts on the Beibu Gulf for a long time, and the Beibu Gulf is on or under the typhoon for a long time, affected by the north and south winds simultaneously, and the increase and decrease of water in the sea area are not consistent. It is difficult for sea water to gather rapidly in a large scale to form a higher storm water increase, with small increase range and more disturbance. There is not a simple correlation between the increase and decrease of storm water and the speed of storm movement in Beibu Gulf. On the one hand, with the increase of cyclone velocity, the component of cyclone field increases in the direction of cyclone movement, which may be beneficial to the increase and decrease of storm water. On the other hand, the speed of cyclone moving becomes larger, which affects the Beibu Gulf for a short time, and the shorter wind time is not conducive to the increase of storm water supply. At the same time, with the change of storm velocity, the fluctuation period of storm surge process changes, the interaction between storm surge level fluctuation and coastal backtide wave also changes, and the actual tide level also changes. The increase of typhoon intensity will increase the amplitude of storm water, and will not affect the frequency of storm surge. The difference of increasing and decreasing water at different stations also reflects the influence of the topography of Beibu Gulf on storm surge. The general trend is that the increase of water in the bay is strong, the increase in water in the open coast is weak, and the increase in water in the sea area is the least. At the same time, the geographical characteristics of the narrow and narrow gulf of Beibu Gulf also lead to the obvious influence of the backtide waves in the Gulf. The water increasing curve of the Beibu Gulf Storm shows the characteristics of Yu Zhen long time and many main vibration disturbances.
【学位授予单位】：上海海洋大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P731.23
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