黄浦江下游吴淞口站低潮位重现期研究

Return period of low tide level at Wusongkou station in the lower reaches of Huangpu River

黄浦江为感潮河流,低潮位重现期的确定对黄浦江航道的设计具有重要意义.为了准确估计黄浦江低潮位的重现期,以黄浦江下游吴淞口站年最低潮位序列为例,在对样本进行三性审查的基础上,分别采用传统的数理统计方法和时变矩方法进行水文频率分析.结果表明:吴淞口站年最低潮位序列在1996年发生了变异;还现修正后的序列服从位置参数线性时变的GEV模型,低潮位存在缓慢的上升趋势;一致性条件下百年一遇低潮位约为0.261 m,在非一致性条件下其重现期增大为150 a.非一致性条件下的重现期增大说明黄浦江现有的航道设计标准偏安全,航道通航保证率提高.

The Huangpu River is a tidal current and the calculation of the return period of low tide level is of great significance to the design of its waterway.In this study,the annual minimum tide level(AMTL)records at Wusongkou Station are used to accurately estimate the return period of AMTL in the lower reaches of Huangpu River.The traditional frequency analysis method and the time-varying moment method are used to analyze the AMTL series on the basis of stationarity examination.The results show that the variation of the AMTL series has happened in 1996 and after the revision,the GEV distribution with a linear time-varying location parameter exhibits the best goodness-of-fit,which indicates a slowly rising trend in the low tide level.The 100-year low tide level is approximately 0.261 m and its return period increases to 150 years when nonstationarity is considered.The increase in the return period under nonstationarity indicates that the existing channel design standards in the Huangpu River are more secure and the navigation guarantee rate is increased.