摘要
三峡工程蓄水后"清水"下泄,长江中游含沙量将会长期处于严重不饱和状态,水流含沙量沿程恢复将会引起长江中游长距离冲刷,本文根据三峡工程蓄水以来的实测资料分析长江中游泥沙输移变化规律,得到以下结论:在"清水"冲刷下荆江三口分流分沙比无明显变化趋势,江湖水沙分配对长江中游含沙量恢复影响较小;其中d<0.125mm粒径沙量在长江中游沿程缓慢恢复且恢复程度远小于蓄水前,这是坝下游河段发生长距离冲刷的根本原因;而d>0.125mm粒径沙量在宜昌-监利河段恢复速率较快,且在监利站附近该粒径含沙量基本恢复饱和,这也造成冲刷重点集中在荆江河段。
Sediment concentrations would not be saturation in a long-term after filling of the Three Gorges Reservoir.As a result,sediment concentration recovery will cause long distance erosion in Middle Yangtze River.Sediment transport in Middle Yangtze River is analyzed based on the field data after filling of the Three Gorges Reservoir in this paper.The result shows that,there was no obvious changes in diversion ratios of flow and sediment through 3 diversion branches,which is less affection to sediment concentration recovery.Sediment discharge recovery of diameter less than 0.125mm is slow,and the degree of recovery is far less than before.This is the fundamental mechanism that long distance erosion occurs downstream dam.However,sediment discharge recovery of diameter larger than 0.125mm is fast on the reach of Yichang ～ Jianli,and sediment saturation concentration is almost recovered at Jianli station,this is the main reason that scour focuses on the Jingjiang River.
出处
《泥沙研究》
CSCD
北大核心
2014年第5期11-17,共7页
Journal of Sediment Research
基金
水利部公益性行业科研专项"三峡水库运用后荆江河道再造过程及影响研究(201401011)
国家青年科学基金项目"次饱和水流下悬移质泥沙输移与驱动机制试验研究(51409017)
关键词
长江中游
含沙量恢复
趋势
middle Yangtze River
sediment concentration recovery
trend
