为了探究江都水利枢纽下游潮水位变化规律及其影响,根据输水口门三江营站逐日资料, 应用趋势分析和周期分析的方法,分析1957—2019年长系列的特征潮位、潮差、潮历时、周期等典型要素的变化规律以及对工程运用的影响。结果表明:多年潮位呈显著增大变化,涨落潮最大潮差呈不显著增大趋势、涨落潮最大历时呈不显著减小趋势,但最大潮差和潮历时在夏季呈现与年趋势相反、在枯水期呈现与年趋势相同的变化。特征潮位、潮差、潮历时均呈周期性变化,特征潮位和最大潮差主周期均约为28 a,涨落潮最大历时主周期约为22 a;根据主周期特征时间长度,特征潮位、潮差、潮历时目前均处于增大阶段,将于2020—2021年进入为期约7~9 a的减小期。该研究对南水北调东线源头充分调引长江水源以及淮河洪水安全下泄具有重要的现实意义,也为更好地掌握长江河口潮流界末端潮流的运动规律提供参考。

According to measured daily data of Sanjiangying station which is located at the outlet of Jiangdu water conservancy project, we analyzed the long-range change rules of typical elements such as characteristic tide level, tidal range, tide duration, and period in 1957-2019 as well as their impacts on the project operation by means of Mann-Kendall trend test, cumulative anomaly and Morlet wavelet analysis. Results demonstrated that: 1) Tide level had been increasing significantly over years, maximum tidal range did not increase significantly, and the maximum duration of rising and falling tide did not reduce significantly, but the maximum tidal range and tide duration showed opposite trend to annual trend in summer and the same trend with annual trend in dry season. 2) The characteristic tide level, tidal range and tide duration all exhibited periodic changes, with the main cycles of characteristic tide level and maximum tidal range reaching about 28 years and the main cycles of maximum rising and falling tide about 22 years. 3) According to the characteristic time length of the main cycles, the characteristic tide level, tidal range and tide duration are currently in an increasing stage and will in 2020-2021 enter a decreasing period of about 7-9 years. This study is of practical significance for the sourcing of the East Route of the South-to-North Water Diversion and the safe discharge of the Huaihe River flood. It also provides a reference for better mastering the law of tidal current movement at the end of the tidal boundary of the Yangtze River Estuary.