北部湾致灾风暴潮与热带气旋路径和强度关系研究

Study on the relationship between disastrous storm surge and the tracks and intensities of tropical cyclone in Beibu Gulf

基于2001—2021年北部湾风暴潮和热带气旋资料,运用相关分析、线性趋势等统计方法分析了北部湾致灾风暴潮的变化特征,探讨了致灾风暴潮与热带气旋路径和强度关系。结果表明:(1)北部湾致灾风暴潮平均每年出现1.8次,序列年际变化趋势不明显,但有显著的阶段性变化特征;月变化呈单峰型,主要出现在6—11月;(2)不同级别风暴潮出现次数差异极大,其中Ⅴ级(一般)风暴潮出现次数最多(22次),其次是Ⅳ级(中等)风暴潮(9次);(3)影响北部湾致灾风暴潮的热带气旋强度年际变化不明显,最强热带气旋出现在11月,最弱热带气旋出现在6月;西路路径的热带气旋引起北部湾致灾风暴潮最大,其次是中路路径,东路没有影响;(4)风暴潮增水与最低气压呈负相关,与最大风速呈正相关,最大增水超过150cm的风暴潮,对应的热带气旋最大风速在40m·s^(-1)以上。

Based on the data of storm surges and tropical cyclones in the Beibu Gulf from 2001 to 2021,the variation characteristics of storm surges in the Beibu Gulf are analyzed by using statistical methods such as correlation analysis and linear trend analysis,and the relationship between disasters causing storm surges and the tracks and intensities of tropical cyclones were also explored.The results show that:(1)The average occurrence of storm surges in the Beibu Gulf is 1.8 times per year.The interannual variation trend of this series is not obvious,but there is a significant phased change characteristic,with a unimodal monthly variation,which mainly occurs from June to November;(2)There are great differences in the frequency of storm surges at different levels,of which the frequency of V-level(general)storm surges is the highest(22times),followed by IV-level(medium)storm surges(9 times);(3)The interramal variation of the intensity of tropical cyclones affecting the disastrous storm surges in the Beibu Gulf is not obvious.The strongest tropical cyclone appears in November and the weakest tropical cyclone appears in June.The tropical cyclones on the west tracks cause the greatest hazardous storm surge in the Beibu Gulf,followed by the middle track,and the east track has no impact;(4)The water gain of a storm surge has a negative correlation with the minimum pressure and a positive correlation with the maximum wind speed.For a storm surge with a maximum water gain of more than 150 cm,the maximum wind speed of the corresponding tropical cyclone is above 40m·s^(-1).