长江中下游河道演变趋势及对策

在概述长江中下游河道演变的基本特点和各类河型的形成条件后着重分析了各种人为因素对长江中下游河道演变的影响。展望２１世纪，人为因素对长江中下游河道演变的影响将加大，主要表现为三峡水利枢纽的建成运用和岸线保护与利用程度的大大提高两个方面。其综合影响的结果是长江中下游各河段的河型和河势不会出现重大调整，河道演变主要表现为河床冲深，河热的局部调整，以及分汊河段支汊的萎缩。

Evolution trend of river course of middle and lower Yangtze and its countermeasures

After the basic features of river course evolution of middle and lower Yangtze as well as the formation conditions of various river patterns are summarized, the impacts of various man-made factors on the river course evolution of middle and lower Yangtze are emphatically analysed. It is estimated that these impacts will increase in the future twenty-first century, and, the major impacts will come from both the operation of TGP and great raising the degree of river bank protection and utilization. Combination of these impacts,however, will not result in substantial variation of river pattern and river regime; and the evolution of river course mainly assumes the river bed scouring,local variation of river regime and river branch atrophy. Before completion of TGP a river regulation planning should be drawn out as early as possible, and carried out step by step, so that the river regime of middle and lower Yangtze will reach the stable state by 2009.