Knowledge Management System Of Institute of Oceanology, Chinese Academy of Sciences
|Place of Conferral||中国科学院海洋研究所|
|Keyword||风暴潮 海岸淹没 Adcirc + Swan模式 围垦工程 危险性评价|
首先，本文针对浙江沿海区域建立了一个由同化台风模型和ADCIRC + SWAN（Advanced Circulation Model + Simulating Waves Nearshore）耦合模式组成的台风风暴潮模拟系统。同化台风模型将来自再分析数据CFSR（Climate Forecast System Reanalysis）和CFSV2（Climate Forecast System Version 2）以及Holland台风模型的台风风速、气压进行了有效的叠加。台风风暴潮模拟系统具有高分辨率的特征，它可覆盖沿岸区域复杂多变的水深和地形。本文通过模拟历史台风“Trami”（2013）和台风“Fitow”（2013）在浙江沿海引起的风暴潮验证了系统的可靠性和准确性。在此基础上，本文基于数值模拟结果讨论了计算域的尺度对台风风暴潮模拟的影响。结果表明，在近海区域网格分辨较高的前提下，计算域网格的大小对浙江台风风暴潮的模拟结果影响不显著。为了提高模式模拟的效率，本文选用仅包含我国东海海域的计算网格来完成浙江台风风暴潮的模拟实验。本文通过对比同化台风模型和非对称Holland模型的台风风暴潮模拟结果，得知同化台风模型模拟的浙江省台风风暴潮更为准确。本文根据已知历史台风“Sinlaku”（2002）、“Morakot”（2009）、“Haikui”（2012）的路径设计了23条新的台风路径，讨论了这些路径对浙江省温州市台风风暴潮的危险性。此外，本文还分类讨论了我国东部沿海的55条历史台风路径对浙江省台风风暴潮的影响。
然后，本文针对珠江口区域研发了一个基于ADCIRC + SWAN耦合模式的海岸淹没模拟系统。该系统采用的非结构三角网格不仅可以同时覆盖沿海地区的陆地和海洋，还可在计算时自动识别网格的干湿特性。本文通过模拟台风“Hope”（1979）、“Nida”（2016）和“Hato”（2017）在珠江口区域引发的台风风暴潮和海岸淹没灾害验证了该系统的有效性、准确性。此外，本文通过多组数值实验的结果，讨论了气象强迫场、台风路径、台风中心移动速度和台风强度对珠江口风暴潮、海岸淹没的影响。结果表明，风场强迫对风暴潮和海岸淹没的贡献率大于气压强迫，且两种强迫之间的非线性相互作用有减弱灾害强度的迹象。台风路径与珠江口海岸的相对位置显著影响了风暴潮与海岸淹没的灾害程度。台风“Hato”的路径最易引发珠江口的风暴潮和海岸淹没。珠江口海岸淹没对台风中心移动速度的敏感性要高于风暴潮。台风强度对风暴潮和海岸淹没的影响是类似的。
近年来，我国的围垦工程对珠江口的海岸线形状、陆地地形和近岸水深有着显著的影响。本文使用1973年、1990年和2018年的海岸线构造了3套计算网格，并用这3套网格模拟台风“Nida”（2016）期间珠江口区域的波高、风暴潮增水和海岸淹没的状况。模拟结果显示围垦工程降低了珠江口区域的有效波高，但并不显著。因此，珠江口有效波高的降低对降低风暴潮和海岸淹没的作用不大。珠江口围垦程度高的地区，近岸海水流速加快，风暴潮增水和海岸淹没加剧。基于珠江口海岸淹没系统模拟了1998年至2018年期间的43次海岸淹没事件，得到了20年的珠江口极端海岸淹没。在此基础上，本文采用Gumbel分布和Weibull-III型分布拟合了整个计算区域的海岸淹没极值，得到珠江口区域10年、50年、100年和200年一遇的海岸淹没。结果表明，在围垦程度较高的区域，海岸淹没的深度更深、面积更大。在此基础上，本文以1 m为淹没深度阈值，划分了珠江口海岸淹没的风险等级。依据淹没深度大于1 m的概率将海岸淹没危险性分为五级，绘制了海岸淹没危险等级区划图。结果表明，广州市南沙区、珠海市金湾区和内伶仃湾沿岸的海岸淹没危险等级普遍较高。
Every summer in the northern hemisphere, China's eastern and southern coastal areas are frequently suffering from tropical cyclones in the Northwest Pacific Ocean. In particular, tropical cyclones with the scale of typhoon induce destructive storm surge disaster and coastal inundation in the southeast coast of China, resulting in great economic losses and serious casualties. In addition, the ever expanding reclamation projects change the distribution of land and sea, thus affecting the hydrodynamic process in the coastal areas. Once the marine dynamic disasters occur, the consequences will be very serious. Therefore, it is necessary to do scientifically study on the risk of typhoon storm surge and coastal inundation. These can not only provide accurate forecast technology for storm surge, but also provide effective evaluation methods for coastal inundation risk in coastal areas of China. This study focus on the coastal of Zhejiang Province and the Pearl River Estuary (PRE) which are located in the southeast coast of China. The typhoon storm surge and coastal inundation are serious in these areas. In view of these two key areas, the main research contents and conclusions of this paper are as follows.
A typhoon storm surge simulation system is established for Zhejiang coastal areas. This system is composed of an assimilation typhoon model and the ADCIRC + SWAN (Advanced Circulation Model + Simulating Waves Nearshore) coupled model. The assimilation typhoon model is obtained by effectively superimposing the wind speed and pressure of typhoons from the Holland typhoon model and the analysis data CFSR (Climate Forecast System Reanalysis) or the CFSV2 (Climate Forecast System Version 2). The system with high resolution can cover the complex and changeable bathymetry and topography of the coastal area. The reliability and the accuracy of the system are verified by simulating historical storm surges of the Zhejiang coastal areas induced by Typhoon Trami (2013) and Typhoon Fitow (2013). On this basis, this paper discusses how the scale of computational domain effect on the simulation results of typhoon storm surge. Upon the premise of high grid resolution in the offshore area, the size of the computational domain has no significant effect on the simulations of typhoon storm surge in Zhejiang coastal area. In order to improve the computational efficiency of the model, this study selects the computational mesh structure only including the East China Sea to complete the simulation experiments of typhoon storm surge in Zhejiang Province. Moreover, it is found that the assimilation typhoon model is more accurate for the Zhejiang’s storm surge by comparing the simulated typhoon storm surge of the assimilation typhoon model and the asymmetric Holland typhoon model. In this paper, 23 new typhoon tracks are designed basing on the historical Typhoon Sinlaku (2002), Typhoon Morakot (2009) and Typhoon Haikui (2012). Then of these typhoon tracks are analyzed to the risk of Wenzhou's storm surge. The influence of 55 historical typhoon tracks is classified and discussed on the storm surge in Zhejiang Province.
A coastal inundation simulation system based on ADCIRC + SWAN coupled model is developed for the PRE, China. The unstructured triangular grid used in the system can not only cover the land and sea of coastal areas at the same time, but also automatically identify the dry grid and wet grid during numerical computing. The system is verified by simulating the historical typhoon storm surges and coastal inundations which are induced by Typhoon Hope (1979), Typhoon Nida (2016) and Typhoon Hato (2017) in the PRE. Some sensitivity experiments are used to analyze the influence of meteorological forcing fields, typhoon tracks, moving speeds of typhoon center and typhoon intensity on storm surge and coastal inundation. The results indicate that the contribution of wind forcing to storm surge and coastal inundation is greater than that of pressure forcing, and their nonlinear interaction tends to weaken the disaster intensity. The relative position between typhoon tracks and the coast of the PRE significantly affects the intensity of the storm surge and coastal inundation. In this study, the track of Typhoon Hato (2017) is the easiest to cause storm surge and coastal inundation in the PRE. Coastal inundation behaves more sensitively to the moving speed of typhoon centre than storm surge. The effect of typhoon intensity on storm surge and coastal inundation is similar.
In recent years, the reclamation projects obviously affect the shape of coastline, land topography and nearshore bathymetry in the PRE, China. Three sets of computational meshes are constructed based on the coastlines of 1973, 1990 and 2018, which are used to simulate the wave height, storm surge and coastal inundation in the PRE during the Typhoon Nida (2016). The results of simulation indicate that the reclamation project reduces the significant wave height of the PRE, but it is not obviously. Thus, the reduction of the significant wave height has little effect on weakening storm surge and coastal inundation in the PRE. In the area with high rate of reclamation in the PRE, the nearshore flow velocity is accelerated, and storm surge and coastal inundation are enhanced. 43 coastal inundation events from 1998 to 2018 are simulated for the PRE basing on the coastal inundation system. Then the 20 years' extreme coastal inundation is obtained. The Gumbel method and Weibull-III method are used to fit the extreme value of coastal inundation in the whole computation domain. Then the 10-year, 50-year, 100-year, and 200-year return coastal inundations are obtained. The results indicate that the coastal inundation with deeper depth and larger area will occur in or nearby the area with higher rate of reclamation. On this basis, 1 m is set as the threshold of inundation depth, and the risk level of coastal inundation is analyzed for the PRE. According to the probability that the inundation depth is more than 1 m, the risk of coastal inundation is defined as five grades. The coastal inundation risk zoning map is drawn and shows that the risk of coastal inundation in Nansha District of Guangzhou, Jinwan District of Zhuhai and the Inner Lingding Bay are generally high.
In conclusion, this study analyzes the risk of typhoon storm surge for Zhejiang Province, discusses the influence of typhoon characteristics and coastline changes on typhoon storm surge and coastal inundation for the PRE. All of these provide theoretical basis and technical guidance for the disaster prevention and mitigation of marine dynamic disasters in the southeast of China. In addition, it is also of great significance to the development of operational forecasting technology and risk evaluation methods of typhoon storm surge and coastal inundation.
|MOST Discipline Catalogue||理学::海洋科学|
|Funding Project||CAS Strategic Priority Project[XDA19060502] ; National Key Research and Development Program of China[2018YFC1407003] ; National Key Research and Development Program of China[2016YFC1402000] ; National Natural Science Foundation of China ; National Natural Science Foundation of China (NSFC)[U1606402] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDA19060202] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDA19060202] ; National Natural Science Foundation of China (NSFC)[U1606402] ; National Natural Science Foundation of China ; National Key Research and Development Program of China[2016YFC1402000] ; National Key Research and Development Program of China[2018YFC1407003] ; CAS Strategic Priority Project[XDA19060502]|
|Table of Contents|
|杜玫. 中国近海台风风暴潮及海岸淹没的数值模拟和危险性评价[D]. 中国科学院海洋研究所. 中国科学院大学,2020.|
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