南海北部夏季定点实测波浪统计分析

Statistical Analysis of the Waves Measured at Fixed Points in the Northern South China Sea in Summer

由于波浪要素的变化对海洋工程设施选址、海上作业和安全生产等工作具有重要的参考价值,故对实测波浪数据进行科学的分析是极为重要的。根据南海北部观测站现场实测资料,分析了1997年6月至8月(夏季)该站位附近的波浪特征,并着重分析了9710号(VICTOR)台风过境波浪特性及波浪谱拟合。为给海洋工程建设提供必要的参考,详细解析了观测期间有效波高按方向出现的频率、平均有效波高和最大有效波高的玫瑰图以及波高、周期联合分布表和波高、波向联合分布表等。统计结果表明,观测期间波浪最大平均有效波高2.77 m,最大有效波高10.66 m,其主波向S,最大平均谱峰周期(Tp)7.9 s;由于台风的影响,这些特征值都发生在1997年8月;并特别指出,9710号台风期间的波浪以风浪为主导,占比64%,台风浪最大有效波高10.66 m,主波向S,谱峰周期10.77 s。经波浪谱分析认为,本观测台风过境期间有效波高高于8 m的波浪谱,可使用波浪JONSWAP谱解析。

It is essential to conduct scientific analyses on the measured wave data because the variations of wave elements have important reference values for the site selection of marine engineering facilities,the operations on the sea and the safety in production.In the present paper,the wave characteristics in the northern South China Sea during June to August in 1997 are analyzed based on the data measured at an observation station,and the wave characteristics and wave spectrum fitting induced by Typhoon 9710(VICTOR)are also discussed.In order to provide necessary references for marine engineering,the detailed statistical characteristics are depicted,which include the frequency at which effective wave heights appear by direction,the rose charts of the average and maximal effective wave heights and the joint distribution tables of wave height-period and wave height-direction.The statistical results show that during the period of observation the maximum average effective wave height is 2.77 m,the maximum effective wave height is 10.66 m,the major wave direction is S and the maximum average spectral peak period(Tp)is 7.9 s.Due to the influence of typhoon,all these eigenvalues occurred in August 1997.It should be pointed out that during Typhoon 9710 wind wave was predominant,accounting for 64%;and the typhoon wave had the maximum effective wave height of 10.66 m,the major wave direction of S and the spectral peak period of 10.77 s.It is considered from the wave spectrum analysis that the effective wave height occurred during this typhoon transit could be higher than 8 m.To know the internal volatility structure of the wave,the JONSWAP spectrum can be used for the further analysis.