广西沿海风暴潮的数值计算研究

NUMERICAL CALCULATION OF STORM SURGES NEAR GUANGXI COAST

采用二维平均流非线性数值模型,模拟了经过北部湾并影响广西沿岸的7703、7812号热带气旋所产生的非周期性水位的变化。其中7703号热带气旋影响广西沿岸的路径偏西,因此,东起北海市,西至白龙尾,极值增水都接近1.3m,是廉江三角洲20世纪90年代以前仅次于1906年、1964年的第三个增水极值。7812号热带气旋影响路径偏东,从北海市向东到铁山港一带,风暴增水比北海市以西显著增高。广西沿岸风暴潮增减水大体存在三个过程:缓慢减水、突然升高、然后持续20个小时的回落。

Using a 2-dimensional nonlinear numerical model, we have calculated the storm surges which were caused by tropical cyclones No.7703 and No.7812 when they approached Guangxi coast . The influence of tropical cyclone N0.7703 on the west coast of Beihai is much stronger than on the east .The values of increasing water level exceeded by 1.3m from Beihai to Bailongwei.On the contrary,the influence of tropical cyclone No.7812 was important on the east coast of Beihai.There were three processes of water level variation for the storm surges: slow decreasing,rapid increasing and slow decreasing again.