摘要
根据近50年来的实测资料,分析了三口分流变化的原因,得到了影响三口分流最主要的因素是荆江河段水位变化以及三口分流洪道冲淤变化,而近期造成这些变化的主要原因是长江干流水沙变化.其中,在1955—1990年期间,荆江河段水位下降、三口分流洪道淤积导致三口分流比急剧递减;1990年至蓄水前,荆江河段水位、三口分流洪道冲淤均变化不大,三口分流比也基本变化不大.三峡蓄水以后,长江干流含沙量将会大幅度地减少,本文结合三峡水库下泄水沙过程及下游河道冲刷的研究成果,估算了三峡水库运行20年后三口分流洪道的冲刷深度以及分流比变化.结果表明:三峡建库20年后,荆江河段中、高水位下降幅度有限,三口分流洪道河床高程下降幅度较大,因而三口分流比将不会减少.
Based on the field data in the last 50 years, the main influence factors on the diversions discharge form Yangtze River to Dongting Lake are analyzed. The results show that the diversion discharges are mainly depend on water level of Jingjiang reach and erosion/ depth of the diversion channels, which are depend on the flow and sediment transport Yangtze River. During 1955-1990, the water level drop in Jingjiang River and the deposition process of deposition of the three outlets led to reduce dramatically in the flow of the three diversions; during 1990- 2002, the above of the two factors had litter changes, so did the three diversions. After the operation of Three Gorges reservoir, the sediment discharge of the Yangtze drainage had greatly decreases, using the research achievement in Lower River course of the Three Gorges reservoir were used to estimate the scour depth in the three outlets and the ghanges in the flow of the three diversions after the Three Gorges Reservoir Being Built 20 years. The results showed that, the magnitude of decrease in medium ＆ high water level was finite in Jingjiang River, the riverbed elevation in the three outlets had drop larger, so the diversion ratio would not be reduced.
出处
《应用基础与工程科学学报》
EI
CSCD
2009年第1期21-31,共11页
Journal of Basic Science and Engineering
基金
国家重点基础研究资助项目(2003CB415200)
关键词
三口
长江
三峡工程
分流洪道
three outlets
Yangtze River
Three Gorges Reservoir
diversion ratio
作者简介
李义天（1957-），男，教授．
