三峡大坝下游荆江河段悬沙浓度垂线分布研究  

Study on vertical distribution of suspended sediment concentration in the Jingjiang reach downstream the Three Gorges Dam

作　　者：贺莉[1] 陈东[1,2] 段光磊 彭玉明 HE Li;CHEN Dong;DUAN Guan-lei;PENG Yu-ming(Key Laboratory of Water Cycle and Related Land Surface Processes,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100049,China;Jingjiang Bureau of Hydrology and Water Resources Survey,Hydrology Bureau of Changjiang Water Resources Commission,Jingzhou 434000,China)

机构地区：[1]中国科学院地理科学与资源研究所陆地水循环及地表过程重点实验室,北京100101 [2]中国科学院大学资源与环境学院,北京100049 [3]长江水利委员会水文局荆江水文与水资源勘测局,湖北荆州434000

出　　处：《泥沙研究》2020年第6期27-32,共6页Journal of Sediment Research

基　　金：国家重点研发计划课题(2016YFC0402303,2016YFC0402406);国家自然科学基金项目(51979264,51779242)。

摘　　要：三峡大坝修建后,大坝下游河道水流中的泥沙输移处于严重的次饱和状态,悬移质泥沙的垂线浓度分布呈现出近底拖尾的新现象,常常造成垂线平均的不饱和参数计算值偏小,甚至出现超饱和的假象,干扰水利工程设计,需要深入分析研究。在搜集整理了三峡建坝前后1986-2013年荆江河段沙市和监利两水文站的实测悬沙垂线分布数据基础上,探讨了三峡工程坝下游河段悬移质泥沙的不饱和输沙特性。实测资料表明,三峡大坝修建后,河道次饱和状态下的细颗粒泥沙缺乏补给,不能满足扬动条件的粗颗粒泥沙在悬沙中比例增大可能是浓度分布近底出现拖尾的一个重要原因。As sediment from the upstream watershed deposited mainly in the Three Gorges Reservoir,the water-sediment regime in the Jingjiang River reach becomes unsaturated.A tailed phenomenon was observed in the vertical profiles of suspended sediment concentration(SSC)measured in the Jingjiang River,which often leads to a considerable underestimate of depth-averaged non-equilibrium coefficient,even a false appearance of an oversaturated sediment regime.Based on the measured vertical distribution data of suspended sediment at the Shashi and Jianli hydrological stations in the Jingjiang River from 1986 to 2013,the unsaturated sediment transport characteristics of suspended sediment in the downstream reach of the Three Gorges Project are discussed.Analyses show that the tailed profiles were induced by the insufficient supply of finer sediment particles after the impoundment upstream and a higher ratio of coarser particles in suspension,which satisfy the incipient condition.

关 键 词：不饱和输沙 悬沙垂线分布 不饱和系数 拖尾现象 荆江河段 

分 类 号：TV142.3[水利工程—水力学及河流动力学]