摘要
研究风暴潮期间的增水过程、振幅和时相特征对提高风暴潮实时预报的精度和减轻灾害损失具有重要价值。采用径流、潮汐、风、波浪耦合模型模拟了孟加拉湾1991-2020年期间对湾顶布里斯瓦尔河口一带增水影响最大的28次热带气旋过程。结果显示,由风暴潮总水位减去天文潮位得到的总增水极值相对于天文潮高潮位的出现时刻集中于涨潮阶段,占总次数的89.3%,并且集中于高潮位前的3h和4h。增水过程呈现“(准)孤立波”和“(准)周期性振动”两大类型,其中孤立波形式的增水过程有的在涨潮阶段便完成,也有的持续一个完整的涨、落潮阶段。风暴潮增水-天文潮相互作用曲线具有与天文潮同样周期的振动特征,其振幅与潮差的大小相关,呈现出“涨峰-落谷”与“涨谷-落峰”两种类型,二者具有180°的相位差。热带气旋的行进方向与潮流同逆向、登陆时的潮相、海岸陷波(边缘波)的形成与传播等是决定总增水极值时相特征的主要动力机制。
The surge process,magnitude and timing are of critical importance for accurate storm prediction and warning as well as hazard mitigation.A total of 28 tropical cyclones that most affected the head Bay of Bengal during 1991-2020 are selected and simulated with interactive forces including wind,tide,wave and river discharge.The occurrence frequencies of the maximum surge cluster in the rising tide,amounting to 89.3%,mostly 3 h and 4 h be-fore the peak tide.The larger maximum surges are associated with phase shift of storm tide from astronomical tide.The surge processes can be classified into“(quasi-)solitary wave”and“(quasi-)periodic”oscillations.The solit-ary-wave-like surge may last only the rising tide or both the rising tide and the falling tide.The non-linear interac-tions between the storm surge and astronomical tide have the same period of a semi-diurnal tide,and their amp-litudes are controlled by tidal range.The surge-tide interaction curves demonstrate two types:one is“peak in rising tide and trough in falling tide”,the other is the opposite.They are 180°out of phase,i.e.6 h for a semi-diurnal tide.The advancing direction of cyclones relative to tidal current,the tidal phase at a cyclone landfall and the formation&propagation of trapped edge surge waves are the dominant mechanism to determine the timing of maximum surges.
作者
王玉海
邓安军
郭传胜
Wang Yuhai;Deng Anjun;Guo Chuansheng(China Institute of Water Resources and Hydropower Research,Beijing 100048,China)
出处
《海洋学报》
CAS
CSCD
北大核心
2023年第6期1-12,共12页
基金
孟加拉湾复杂河网区火电站取水防沙及航道维护关键技术研究(HT-18-BARISAL-HT-087)。
