21世纪末珠江口深圳最高潮位重现期值预估

Projections of Maximum Sea Level Recurrence Interval near Shenzhen at the End of the 21^(th) Century

采用P-Ⅲ适线拟合法分析赤湾验潮站建站以来的潮位资料,得出该站1965―2014年最高潮位的重现期值:其中100 a一遇最高潮位为2.31 m,50 a一遇最高潮位为2.18 m。通过插值法分析1965―2011年赤湾站与北角/鰂鱼涌站的年最高潮位,得出两者存在显著相关关系,并据此后报出赤湾站近百年来2次最高潮位为1962年2.7 m和1937年2.34 m。。根据IPCC AR5中的RCP2.6方案,预估了21世纪末(2081―2100年)赤湾最高潮位的重现期:100 a最高潮位在全球海平面上升0.24 m的情况下为2.55 m,在全球海平面上升0.40 m的情况下为2.71m。并讨论了围海造地导致伶仃洋潮位上升率降低以及0814号台风"黑格比"对赤湾站增水的影响:赤湾北面西乡沿海地势特别低,当潮位≥1.40 m(珠基起算)时,就会发生海水倒灌现象。也就是说,未来海平面的上升将加大该区海水倒灌频率。通过分析台风过境时该站的潮位观测资料,得出0814号台风"黑格比"经过珠江口时赤湾站的最高潮位为增水1.46 m。最后,重新修订了赤湾站最高潮位的重现期值,这不但能够提高该区域防台水位设计的准确性,还能为该海域的风暴潮预警预报提供参考依据。

The Chi-wan tide gauge station is the only oceanic tidal observation site on the west coast of Shenzhen that belongs to the State Oceanic Administration. Due to its special geological location, the Chi-wan Station is of significant importance in many fields, including sea level rise, storm tide prediction, and so on, in our country. In the present study, the tidal data of Chi-wan station ever since it was established were analyzed using a P-III curve-fitting method. The maximum sea level recurrence intervals at this station during 1965-2014 were obtained. The maximum sea level was 2.31 m for a one-hundred-years return period and 2.18 m for a fifty-years return period. Using an interpolation method, the yearly maximum sea levels at Chi-wan Station （x） and North Point/Quarry Bay Station （y） in Hong Kong during 1965-2011 were analyzed. It was found that there existed a significant correlation between x and y. The maximum sea levels in the recent one hundred years at Chi-wan station can thus be hindcast to be 2.7 m in 1962 and 2.34 m in 1937. According to the RCP2.6 in IPCC-AR5, the maximum sea level recurrence interval at Chi-wan Station at the end of the 21th century （during 2081-2100） was also projected. It is projected to be 2.55 m for a one-hundred-year return period if the global sea level rises by 0.24 m and 2.71 m if the global sea level rises by 0.4 m. Finally, the influence of land reclamation on the sea level rising rate in the Ling-Ding waters and the influence of the No.0814 typhoon Hagupit on the storm tide at Chi-wan were discussed. The near shore terrain of Xixiang, which is located at the north part of Chi-wan, is very low. When the sea level exceeds 1.40 m, sea water will flow backwards in this area. That is to say, sea level rise in the future will increase the frequency of seawater flowing-backward near Chi-wan Station. Also, by analyzing the tidal observation data when typhoon passed by, it was found that, when typhoon Hagupit passed the Pearl River Estuary, the maximum sea level at Chi-wan Station increased by 1.46 m. In the present study, the maximum sea level recurrence interval at Chi-wan station was revised. This can not only improve the accuracy of water level warning in this area, but also provide reference for the prediction and precaution of storm tide in this sea area.