中文摘要：

利用长江口沿程11个潮位站的潮位数据，统计分析1996-2011年各站年平均高潮位、年平均低潮位和年平均海面，得出长江口海域近期的潮汐特征值变化，分析相关影响因素，探讨长江口近期潮汐特征变化的原因。结果表明：1996年以来，各潮位站的平均海平面略有抬升，但变化幅度不大；流域来水变化对河口潮汐特征值变化影响不大；从长期看，全球气候变暖对海平面变化有一定影响，但短期内的影响不大；短期内，主要受到长江口地区近年来各类涉水工程建设的影响，具体表现为：平均高潮位下降、平均低潮位上升、潮差减小，涨潮历时缩短、落潮历时延长，年最低低潮位上升等。长江口不同河段因受径流、潮流、工程建设等因素的影响程度不同，其潮位特征值沿程的变化特点也不同，需要在河口工程设计、防洪减灾与河口治理等方面引起重视。

英文摘要：

According to data from 11 tidal stations of the Yangtze estuary, this paper analyzes the mean high tide, mean low tide and mean sea level of each station from 1996 to 2011, and finds the recent change of tidal characteristics in the Yangtze estuary, analyzes related factors, discusses the reasons of recent changes of tidal characteristics in the Yangtze estuary. The results show that the mean sea level of each tidal station rises a little bit. The basin’s runoff change seems no influence on the estuarine tidal characteristic value. Global warming has some effect on the mean sea level change in the long term, but it has little impact in the short term. It is affected by the engineering construction of the Yangtze estuary in recent years, which shows that the mean high tide level is going down, the average low tide is rising, the tidal range is decreasing, the flood time is shortened, the ebb time is extended, and the annual lowest tide is rising. The Yangtze estuary is influenced by the runoff, tidal current and engineering construction, and the tide’s characteristic value changes along the way are also different, so we should pay more attention to the estuarine engineering design, flood control and river estuary management, etc.