长江中下游河道近50年变迁研究

 近50年来长江中下游河道演变分析表明,河道演变具有如下特点:河道总体河势基本稳定,局部河势变化较大;河道总体冲淤相对平衡,部分河段冲淤幅度较大;荆江和洞庭湖关系调整幅度加大;人为因素未改变河道演变基本规律;坐崩是长江中下游岸线崩退和护岸工程崩毁的主要形式;人为因素对长江口河道演变的影响增加。

Study on evolution of middle and lower reaches of Yangtze River in recent fifty years

The analysis on fluvial processes of Middle and Lower reaches of Yangtze River in recent fifty years shows that:(1)the river regime of all reaches as a whole is stable,but there are relatively obvious changes in some reaches;(2)the erosion and siltation of all reaches is in a state of relative equilibrium,but variations in some reaches are rather noticeable;(3)the regulating ranges of relation between Jingjiang River and Dongting Lake increased;(4)the regularity of fluvial processes has not been changed under human activities;(5)rotational slip is a major mode of banks failure and river bank protection works;(6)the impact of human activities on the fluvial processes of the Yangtze River estuary is increasing.