珠江河口风暴潮增水特征及经验预报

Characteristics of storm surge water level and empirical forecasting at the Pearl River Estuary

  • 摘要: 珠江河口受强台风影响频次较高,地处粤港澳大湾区核心区域,经济发达,风暴潮灾害通常给其造成严重损失。基于珠江河口典型水文站澳门内港站近50年长序列潮位资料,分析得出澳门内港站45%的年极值潮位是受台风影响导致,实测潮位极值发生在天文高潮位前后1 h内的概率约为82%,而增水极值与天文潮极值相位呈现较为明显的非均匀双峰分布,增水峰值发生在天文潮高潮位的频率仅5%。台风路径及登陆点对风暴潮增水的数值、持续时间等特征要素均有较大影响。西北向和西进型路径台风造成风暴潮增水较大且占比多,造成超30 cm增水的次数约占台风影响总次数的90%。当内港站位于台风的左半圆时增水量值相对较小;当内港站位于台风右半圆,增水幅度相对更大,同时存在登陆点越靠西、风暴潮增水持续时间更长、增水幅度越小的趋势。还建立了风暴潮增水与台风强度、路径、登陆点的极值增水预报公式,拟合值与实测值的拟合度高。本研究可为区域风暴潮预报及灾害防控提供参考。

     

    Abstract: The Pearl River Estuary, located in the core area of the Guangdong-Hong Kong-Macao Greater Bay Area, is frequently affected by strong typhoons. As an economically developed region, it often suffers severe losses from storm surge disasters. Based on nearly 50 years of long-term tidal data from the Macau Inner Harbor station, a typical hydrological station in the Pearl River Estuary, this study analyzes that 45% of the annual extreme water levels at the Macau Inner Harbor station are caused by typhoon events. The probability of extreme water levels occurring within 1 hour before and after the astronomical high tide is approximately 82%. The extreme water level distribution shows a distinct non-uniform bimodal pattern, with the peak occurring in only 5% of the cases coinciding with the astronomical high tide. The path and landfall location of typhoons have significant impacts on the characteristics of storm surge, including its magnitude and duration. Typhoons with a northwestward or westward path cause larger storm surge and account for the majority of cases with over 30 cm of storm surge, approximately 90% of the total. When the Macau Inner Harbor station is located in the left semicircle of a typhoon, the storm surge is relatively small, while it is larger when the station is in the right semicircle. Moreover, a trend is observed where storm surge duration is longer and surge magnitude is smaller when the landfall point is closer to the west. Empirical formulas for extreme surge forecasting considering typhoon intensity, path, and landfall location are established and show a high degree of fitting with the observed values. This study provides valuable references for regional storm surge forecasting and disaster prevention and control.

     

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