长江下游感潮河段大洪水和特大洪水的形成及趋势

Formation and Change Trend of Large Flood in the Lower Tidal Reach of the Yangtze River

分析了长江下游感潮河段大洪水和特大洪水高水位形成的水文因素，揭示了年最高水位今后一段时期内可能的变化趋势。主要结论是：该河段大洪水和特大洪水高水位的形成原因十分复杂，本世纪以来每次大洪水和特大洪水高水位的形成几乎都有其主要原因；该河段大洪水特大洪水高水位出现的频次有增加趋势；自１９７５年以来，年最高水位的均值呈明显的升高趋势，其主要原因是人类活动对防洪产生的负面影响，海平面上升也有一定的影响。

Hydrological factors of formation of large flood in the lower tidal reach of the Yangtze River are analyzed, and change trend of large flood is revealed. Obtained conclusions are: (1)Formation of large flood in the river reach is very complex; (2)Occurrence frequency of large flood in the river reach has been increasing since 1900; (3) The mean value of the peak stage has been rising since 1975; and (4) Above the charcteristics of occurrence of large flood in the river reach are primarily affected by human activity and rise of sea level.