长江下游土桥分汊水道分流比的影响因素及发展趋势  

Influencing Factors of Split Ratio and Development Trend of Tuqiao Braided Channel in Lower Reaches of Yangtze River

作　　者：余文钧 李义天[1] 韩剑桥[1] 

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072

出　　处：《水电能源科学》2015年第5期69-72,共4页Water Resources and Power

基　　金：国家重点基础研究发展计划(973计划)(2010CB429002)

摘　　要：鉴于土桥水道分流比变化直接关系到其水道的航道条件,以1959~2012年的实测地形、水文以及大通水文站来流资料为基础,基于主流摆动理论,分析了长江下游土桥分汊水道分流比的影响因素,并预测了其未来的发展趋势。结果表明,流量过程变化是土桥水道分流比变化的主要因素,即土桥水道冲刷动力最大区域随流量增大向左摆动,流量小于20 000m3/s的持续时间越长,越利于右汊的冲刷发展及右汊分流比的提升,流量大于40 000m3/s的持续时间越长,越利于左汊的冲刷发展及左汊分流比的提升。三峡水库蓄水后来流消峰补枯的变化特点将更加明显,土桥水道右汊将持续冲刷,而左汊分流比将继续下降。In view of the fact that the split ratio of Tuqiao is directly related to the channel condition, based on the topographic and hydrological data and discharge from Datong hydrological station during 1959 to 2012, combined with the mainstream theory, the influencing factors on the variety of Tuqiao split ratio are analyzed. And then the trend of split ra- tio of Tuqiao is predicted. The results show that the main factor for the changes of Tuqiao split ratio is the flow, that means the maximum erosion dynamic turned left as the flow increasing; the duration of less than 20 000 m3/s lasts lon- ger, the more benefits to the scoring and the split ratio increasing of right branch; the duration of more than 40 000 ma/s lasts longer, the more benefits to the scoring and the split ratio increasing of left branch. The flood reducing and the low water increasing become ever more evident during Three Gorges reservoir storage. The right branch of Tuqiao will scour continually and the split ratio of left branch will continue declining.

关 键 词：分汊水道 分流比 流量过程 影响因素 预测 

分 类 号：TV147[水利工程—水力学及河流动力学]