泥沙研究

三峡水库建成后 ,长江中下游河道将遭受长河段、长时期冲刷 ,河床河性会发生很大变化。那时各河段的河型是否仍能保持 ,特别是最为关心的下荆江蜿蜒性河型能否维持 ,这对防洪和航运是非常重要的。本文在研究丹江口水库下游汉江弯曲 (蜿蜒 )河段在长期冲刷后的河床变形和河型是否变化以及荆江裁弯后下荆江中的蜿蜒性变化能够维持的基础上 ,结合三峡水库修建后在长期冲刷过程中 ,下荆江水沙及河床变化特点 ,较深入地研究了影响河型变化的各方面的因素 ,最后认为将来需要的坡降富余 ,主要靠冲刷不平衡导致的落差减少来平衡 ,蜿蜒性河型能维持 ,但曲折率会有所减少 ;河道会展宽 ,但河相系数不会加大 ,没有向微弯顺直河型发展的趋势

After completion of the Three Gorges Project,a long time erosion will occur in the middle and lower reaches of Yangtze River,and the characteristics of river channel will be changed obviously.Wheather the original river pattern witl be maintained or not in these reaches,especially in the reach of Lower Jingjiang River,it is very important for flood control and navigation.In this paper,based on the research of fluvial process for meandering reach in the downstream of Danjiangkou Reservoir on the Hanjiang River,and for the variation of meandering reaches of Lower Jingjiang River after the practice of cut\|off project,the tendency and effective factors of river pattern variation in the Lower Jingjiang River after the impounding of Three Gorges Reservoir have been studied.The obtained conclusions are that:after compeltion of the Three Gorges Poject in the Lower Jingjiang River the unnecessary slope will be balanced by the reduction of water level difference,and the original meandering river pattern will be kept,although the meandering degree could be reduced slightly.