近岸海域地形复杂性对潮汐特征的影响研究——以南黄海及东海北侧海域为例

Response of Nearshore Tidal Characteristics to Terrain Complexity:Taking the South Yellow Sea and the Northern Waters of the East China Sea as Examples

南黄海及东海北侧海域近岸地形复杂,受地形影响其潮位预报精度低,研究近岸地形复杂度对潮汐特征的影响对提高预报精度很有必要。基于系列长期验潮站实测潮位和近岸地形等基础数据,采用调和分析及相关性分析等方法分析了近岸潮汐特征对地形复杂度的响应。研究发现,验潮站周围地形越复杂,K1分潮振幅越小、M2、M4分潮振幅越大;随着地形复杂程度的提高,海域的潮汐变形越显著,潮时不等现象越显著,表明南黄海海域的地形复杂程度是其潮汐变形和潮时不等现象的主要因素;验潮站附近海域地形越复杂,其调和分析的精度越差,其绝对余水位越大,说明地形也是影响验潮站潮位精度和余水位的主要因素。探讨了基于地形复杂度修正的调和分析方法,并经验证各验潮站调和精度均有不同程度的提高。

The tidal forecast shows low accuracy due to the complex offshore topography of the South Yellow Sea and the north side of the East China Sea,so it is necessary to study the influence of offshore topographic complexity on the tidal characteristics to improve the forecast accuracy.Based on a series of basic data such as measured tide levels from long-term tide stations and offshore topography,the response of offshore tidal characteristics to the topographic complexity was analyzed by harmonic analysis and correlation analysis.According to research findings,the more complex the topography around the tide station,the smaller the amplitude of the K1 constituent and the larger the amplitude of the M2 and M4 constituents.Tidal deformation and tidal time in‐equality become more pronounced with increasing topographic complexity,which indicates that the topographic complexity of the South Yellow Sea area is the main factor of its tidal deformation and tidal time inequality.As the topographic complexity of the sea near the tide station increases,the accuracy of its harmonic analysis decreases and its absolute residual water level becomes larger,indicating that the topography is also the main factor affecting the accuracy of the tide level measured by the tide station and the residual water level.The method of harmonic analysis based on the correction of topographic complexity is discussed,and it is verified that the harmonic accuracy of each tide station is improved to different degrees.