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对塘沽海洋环境监测站从1950年—2008年,59年的潮汐资料进行调和分析,分析了其分潮调和常数的变化曲线,并利用FFT谱分析方法对其调和常数的变化周期和原因进行了分析;之后应用FFT谱分析方法对去除天文潮后的余水位进行分解,分析了近50多年来年平均余水位的多层次周期分布,进而利用最小二乘法进行线性分析,分析了天津近海平均海平面的变化趋势。结果表明,天津沿岸潮汐M2分潮振幅变化存在20年、4—6年、2—3年的周期,且明显受到改革开放后工程建设的影响;余水位变化包含着20年、5—6年、2—3年、1年等不同周期的时间尺度变化,天津近海海平面呈逐渐上升趋势,上升幅度约为3.4mm/a,主要受海平面上升和地面沉降两部分因素影响。
Tide data of Tanggu Marine Environmental Monitoring Station from 1950 to 2008 and 59 years are analyzed and the curve of the harmonic constant is analyzed. The period and reason of the harmonic constant are analyzed by using FFT spectrum analysis After that, the residual water level after removing astronomical tide is decomposed by FFT spectral analysis method, and the multi-level periodic distribution of annual average residual water level in the past 50 years is analyzed. Then the linear analysis is made by the least squares method. The mean sea level The trend of change. The results show that there is a period of 20 years, 4-6 years and 2-3 years in tidal amplitude of tidal M2 in tianjin, and obviously affected by the construction after the reform and opening up; the variation of residual water level includes 20 years and 5-6 years , 2-3 years, one year and so on. The sea level of Tianjin offshore is gradually increasing. The increase is about 3.4mm / a, which is mainly affected by sea level rise and land subsidence.