东方市近岸海域波浪特征分析

Analysis of wave characteristics in the offshore area of Dongfang City

为了解海南东方市近岸海域波浪基本特征,根据东方海洋环境监测站使用的SZF型波浪浮标连续11 a的实测数据,进行了统计分析。首先对波浪要素进行统计,得到了各向各级波高的季节分布,以及波高和周期的均值与极值;再对波高和周期的联合分布、平均持续时间与波高的关系进行了探讨;最后选取一典型台风浪过程进行分析。结果表明本海域以S向浪出现频率最高,为14.3%,其次是N向和NNE向,频率均为11.9%;强浪向为S向和N向,浪向分布与东方市所处地理位置相符。该海域以有效波高小于1.3 m的小浪和轻浪为主,年出现频率为97.6%,4级中浪占2.22%,5级大浪仅占0.12%,只有在夏、秋季台风过境时才出现。累年有效波高平均值为0.49 m,最大值为3.2 m;最大波高为5.6 m,最大波高平均值为2.5 m;平均有效周期为4.2 s,最大有效波周期为9.5 s。有效波高在1.0 m以下,且周期在4~5 s的波浪出现频率最大,为80.5%。强台风“海燕”影响期间,波高具有明显的滞后特征,5级大浪持续了10 h,浪向与风向基本一致,说明台风产生的波浪是以风浪为主,最大波高均出现于偏S向。通过波谱分析,台风海浪的波型变化规律为混合浪-风浪-混合浪。

Based on the 11-year measured data of SZF Wave Buoy from the Dongfang Marine Environmental Monitoring Station,this paper statistically analyzed the basic characteristics of waves in the offshore area of Dongfang City.Firstly,the seasonal distribution of wave heights at all levels in all directions,as well as the mean and extreme values of wave heights and periods are obtained by statistical analysis of wave elements;The joint distribution of wave height and period,and the relationship between average duration and wave height are discussed;Finally,a typical typhoon wave process is selected for analysis.The results show that the wave frequency in S-direction is the highest in this sea area,accounting for 14.3%,the frequency is 11.9%in the N-direction and NNE-direction,and the strong wave is in the S-direction and N-direction,which is consistent with the geographical position of Dongfang City.In this sea area,small waves and light waves with effective wave height less than 1.3 m are dominant,at the annual frequency 97.6%,the middle wave of grade 4 is 2.22%,and the big wave of grade 5 is only 0.12%.The average and the maximum annual effective wave height are 0.49 m and 3.2 m,respectively.The maximum wave height is 5.6 m and the average maximum wave height is 2.5 m.The average effective period and the maximum effective wave period are 4.2 s and 9.5 s respectively.The wave with significant wave height below 1.0 m and period of 4~5 s has the maximum frequency of 80.5%.During the impact of strong typhoon“Haiyan”,the wave height had obvious hysteresis characteristics,The magnitude 5 wave lasted for 10 hours,and the wave direction is basically consistent with the wind direction,indicating that the wave generated by typhoon is mainly wind wave,and the maximum wave height appears in the S-direction.According to the spectral analysis,the wave pattern change law of typhoon is mixed wave—wind wave—mixed wave.The research work in this paper can provide reference basis for marine disaster prevention and mitigation,and the development and utilization of marine engineering.