【作者】 卢美；

【导师】 孙志林； 黄赛花；

【作者基本信息】 浙江大学 ， 海洋建筑物与环境， 2013， 博士

【摘要】 风暴潮灾害居我国海洋灾害之首,浙江省是我国沿海台风暴潮灾害最严重的区域之一在全球气候变暖背景下,浙江省台风暴潮灾害频率、强度和影响范围呈增大趋势。基于实况资料分析和风暴潮数值模拟开展浙江沿海台风暴潮灾害风险评估具有重要的意义。本文在系统梳理和借鉴前人研究成果的基础上,探讨了浙江沿海台风风暴潮灾害风险的内涵,针对台风风暴潮灾害影响的多种时空尺度和区域特征,分别采用适宜的评估方法开展了浙江沿海地区的台风风暴潮漫堤风险分析、典型沿海岸段台风风暴潮漫堤和淹没风险的实证研究并利用GIS平台直观展现。主要研究工作和结论如下：(1)根据海洋预报部门现有风暴潮灾害危险性评估指标体系,系统地分析了浙江沿海地区风暴潮灾害的危险性,计算了270次台风条件下风暴潮灾度值,从而确定了浙江沿海地区风暴潮危险性分布和灾害等级分布。研究表明：浙江沿海为台风暴潮重灾区,尤以温州沿海灾度最高,杭州湾及台州沿海次之,灾度在空间上具有南部大于北部、河口大于岛屿的分布特征。(2)基于浙江沿海60余年平均气温和潮位观测资料,首次系统分析了气候变化对浙江海域风暴潮的影响,研究表明平均气温变化与风暴潮强度具有明显的正相关。60多年来,浙江沿海登陆台风个数、平均海平面高度、较大风暴增水出现频率、超警戒风暴潮频率和年极值高潮位与平均气温变化趋势非常相似,都呈波动上升趋势。特别是1990年以来,随着平均气温上升,上述趋势更为明显,登陆浙江的台风成倍增加,从而导致浙江沿海风暴潮灾害危险性增大。且台风登陆点似有南移的趋势,浙江南部为台风暴潮主要受灾区。(3)使用1951-2012年全国年平均气温、NINO3.4区海温距平、登陆中国的台风、登陆浙江的个数和乍浦站1954-2012年乍浦站年最高潮位资料,应用小波分析方法,分析了上述各要素的变化趋势及其周期。研究表明：全国年平均气温、登陆浙江的台风个数、乍浦站年最高潮位的长周期变化非常相似,其长周期大于60年,这些要素60年时间序列中只分离出一个跨度为35-40年的上升周期,2007年之后该上升周期都已呈现终结的趋势。而平均气温、NINO3.4区海温距平、登陆中国和浙江的台风个数以及乍浦站年极值高潮位都具有10-11年的短周期。(4)以海门站为例,分析了浙江强潮河口地区的风暴潮增水特征,并应用EMD(经验模态)方法对海门站增水超过1米的17个风暴潮个例进行分析,结果表明,海门站的风暴增水具有明显的潮周期特征,风暴潮与天文潮的非线性效应显著,当该站增水曲线为标准型时,由非线性相互作用引起的增水较小,其值占总增水的比例仅为六分之一左右;当为混合型增水时,增水波的波动特征开始明显,该类型曲线由非线性相互作用引起的增水较大,其值占总增水的比例为三分之一左右；波动性增水的非线性相互作用引起的增水最大,其值占总增水的比例可达二分之一以上。(5)采用ECOMSED建立两潮耦合模型,经过多个历史风暴潮个例的模拟验证后表明,该方法能很好地模拟浙江沿海包括河口地区的风暴潮位及增水过程,说明模型参数取值合理,可用于浙江沿海台风暴潮模拟和漫堤风险评估,该方法可以有效分析无潮位资料岸段的风暴潮特征。对不同登陆点的台风引起的增水特性分析得知,登陆点右侧且靠近登陆点的岸段,风暴增水最大,且形态以标准型为主,其最大增水值是登陆点左侧的3倍左右,为风暴潮灾害风险最大的区域；登陆点右侧距离登陆点较远的以及登陆点左侧的岸段,其增水值较小,且形态多呈波动型;在同一台风影响下,河口类型测站的增水值较岛屿类型大,河口地区的风暴潮灾害风险大于岛屿地区。(6)采用频率分析和数值模拟方法,首次建立了浙江海堤风暴潮漫堤风险分析业务化系统框架。利用不同重现期的风暴潮与天文潮的组合研究表明,在高标准海塘建成后,浙江沿海风暴潮漫堤风险主要集中在20年一遇等级以下的堤坝,而50年一遇及以上等级堤防的漫堤风险较小。据统计,浙江沿海验潮站的历史最高潮位大都接近或超过当地20年一遇标准的堤坝高程,没有超过50年一遇的堤坝高程。(7)首次采用台风概率预报和风暴潮两潮耦合预报相结合的方法来分析任一台风影响下浙江海堤的风暴潮漫堤概率,研究表明采用该方法能平滑由于单一台风路径预报误差引起的风暴潮预报偏差幅度,使得风暴增水和高潮位预报误差更稳定。而且随着台风预报准确度不断提高,风暴潮的预报准确度可以得到稳步提升。此方法可用于风暴潮业务化预报,也可以用于风暴潮漫堤风险事前评估(8)利用skyline和GIS技术,集成了台站实况观测、台风路径预报、两潮耦合数值预报结果和漫堤概率预报结果等信息,构建了适用于浙江沿海的风暴潮灾害预警辅助分析系统,该系统可以利用GIS的空间分析与显示技术,分析并直观展现任一台风暴潮灾害危险区分布和海堤漫堤风险段的分布,该系统已于2011年在浙江省防汛办的防台会商会议得到应用。更多还原

【Abstract】 Storm surge disaster is the most severe one in the oceanic disasters of China, while Zhejiang Province is the most serious region of typhoon storm surge disaster along the coast of China Under the background of global warming, the frequency, intensity and impact range of Zhejiang province storm-surge disaster increases. Based on the observational data analysis and storm surge numerical simulation, the risk assessment of storm surge disasters in Zhejiang coastal area is of great significance to carry out.By systematically combing and following the precedents by previous research, we discussed the connotation of Zhejiang coastal typhoon storm surge disaster risk in this paper, aiming at various temporal and spatial scales and different regional features of typhoon storm surge disasters, appropriate evaluation methods has been use to carry out the Zhejiang coastal storm surge and seawall overflowed risk analysis, storm surge seawall overflowed and flood risk demonstration research of typical coastal area and a visual display by the use of GIS platform.The man research work and concl usi ons are as f ol I ows:(1) According to the existing storm surge disaster risk evaluation index system, it systematic analysis of the risk of storm surge disasters in the coastal region of Zhejiang Province.270typhoon storm surge disaster degree was calculated, so as to determine the risk distribution and disaster level distribution of Zhejiang coastal storm surge. Research shows that Zhejiang coastal region is severe storm surge disaster area, while Wenzhou coastal area is especially the highest in the disaster degree, the Gulf of Hangzhou and the coast of Taizhou take the second place. The disaster degree in space has a distribution characteristic that the south is more than north, while the estuary is more than island.(2) Based on60years of Zhejiang coastal average temperature and tidal observation data, the analysis of the i nf I uence on Zhej i ang sea storm surge due to cl i mate change i s the fi rst ti me.Studies show that the average temperature and the intensity of storm surges have obvious positive correlation. Over the past60years, all of Zhejiang coastal landing typhoon number, mean sea level, larger storm surge frequency, ultra warning storm surge frequency and annual extreme high tide level have a very similar trend as mean temperature, which rises. Snce1990, especially, along with the rise of average temperature, the trend just mentioned is more obvious. Zhejiang landing typhoon multiplied, whiletyphoon landing point has a southward trend, which resulting the increase of storm surge disaster risk in Zhejiang coastal region.(3)Using1951to2012national annual average temperature, SSTA in NINO3and4, the number of typhoon landed in China and Zhejiang, and annual highest tide data of Zhapu station from1954to2012, by using the method of wavelet analysis, this paper analyzed the trend and period of factors above. It shows that:long-term variation periods of the national annual average temperature, the number of typhoon landing in Zhejiang, and the highest tide of Zhapu station are very similar, which is more than60years. There is only a span of35-40years of rising period can be separated from these elements in the time series of60years. And this rising period has been presented to end trend after2007. While a short period of10-11years can be found in national annual average temperature, SSTA in NINO3and4, number of typhoon landing in China and Zhejiang, and extreme high tide in Zhapu station.(4)Taking Hamen station as an example, this paper analyzed the storm surge characteristics of strong tidal estuary areas in Zhejiang, and17storm surge cases in Haimen station which has a surge of more than1meter using the application of EMD (Empirical Mode). The results show that the storm surge in Haimen station has obvious characteristics of tidal period, while the nonlinear effect of the storm surge and astronomical tide is significant. When the surge curve of the station is standard, the surge which is caused by the nonlinear interaction is quite small, which proportion in the total value is only about1/6. When the surge curve of the station is mixed-type, the fluctuation characteristics of the surge becomes significant. The surge caused by the nonlinear interaction effect is larger, and its proportion in the total value is about1/3. The surge caused by the nonlinear interaction of volatile surge is maximum, which proportion in the total value can reach more than1/2.(5) Using ECOMSED to establish the two-tide coupling model, after the simulation verification of several historical storm surge cases, it shows that the method can simulate the tide and storm surge well in Zhejiang coastal area, including estuary. It means that the model parameters is reasonable, which can be used for Zhejiang coastal storm surge simulation and seawall overflowed risk assessment and effective analysis of storm surge characteristics of no observational tidal data region. According to the analysis of surge characteristics in different landing areas of typhoon, firstly, it shows that storm surge of the shore which near and on the right side of the landing point is the largest, most of which has a form of the standard type. Besides, the maximum water value is about3times as which on the left landing point. Hence, it has the largest the risk of storm surge disaster in this region. Secondly, storm surge of the shore which far away or on the left side of the landing point is much smaller, which has a form of wave type. Thirdly, the water values in estuary are larger than that around the island in the same typhoon. Hence, storm surge disaster risk of estuary area is greater than the island.(6) By using the frequency analysis and the numerical simulation method, the system framework of operational Zhejiang seawall overflowed risk analysis of storm surge has been established for the first time. Analyzing the combination of storm surge and astronomical tide in different return period, it shows that Zhejiang coastal storm surge seawall overflowed risk mainly concentrated i n the dam whi ch bel ow the standard of20years, whi I e the seawal I overf I owed ri sk of standard in50years and above is quite small. According to statistics, the highest tide level in history is close to or higher than the20years standard dam height of Zhejiang coastal tidal station, while it is lower than the50years standard.(7) Using the combination method of typhoon probability prediction and storm surge two coupled tidal forecast, it is analyzed, for the first time, the probability of Zhejiang storm surge seawall overflowed under the influence of either of typhoon. This method can smooth the deviations due to the storm surge forecast inaccuracies caused by single typhoon path prediction, which reduces storm surge and tidal level prediction error. The storm surge forecast accuracy can be steadily as long as the typhoon forecast accuracy increased. Hence, this method can be used to forecast the storm surge operationally and do the risk assessment of storm surge seawall overflowed.(8) Using skyline and GIS technology, it integrate station observation, typhoon path prediction, two coupled tidal numerical prediction results, the overtopping probability forecasting results and other information. It construct a storm surge disaster warning and assistant analysis system for Zhejiang coastal for the first time, which can display the distribution of either of typhoon storm surge disaster risk zone and seawall overflowed risk coastline. It has been used in the Typhoon Defending Conference of Zhejiang Flood Control Office in2011.更多还原