三峡水库蓄水后下游河道悬沙恢复效率  

Efficiency of suspended sediment recovery in the downstream reaches of the Three Gorges Reservoir

作　　者：陈立[1] 王愉乐 邹振华 李雨晨 余博闻 余长伍 CHEN Li;WANG Yue;ZOU Zhenhua;LI Yuchen;YU Bowen;YU Changwu(State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,China;Middle Changjiang River Bureau of Hydrology and Water Resources Survey,Yangtze River Water Resources Commission,Wuhan 430010,China;Hubei Tianguan Water Conservancy Project Management Office,Qianjiang 433199,China)

机构地区：[1]武汉大学水资源工程与调度全国重点实验室,湖北武汉430072 [2]长江水利委员会水文局长江中游水文水资源勘测局,湖北武汉430010 [3]湖北省田关水利工程管理处,湖北潜江433199

出　　处：《水科学进展》2023年第5期697-707,共11页Advances in Water Science

基　　金：国家重点研发计划资助项目(2016YFC0402101);三峡工程泥沙重大问题研究项目(12610100000018J129-03)。

摘　　要：受诸多因素影响,枢纽下游不饱和水流冲刷过程中悬移质泥沙含沙量沿程恢复非常复杂。为了进一步弄清枢纽下游悬沙沿程恢复的规律,本文引入含沙饱和度及饱和度恢复效率系数分别描述悬沙恢复的程度和效率,基于宜昌—大通河段的实测水沙资料,分析悬沙恢复效率的变化趋势及其影响因素,并建立计算饱和度恢复效率系数的经验公式。结果表明:(1)三峡水库下游河道不同河段的恢复效率随时间未出现一致的趋势性变化,但总体上沿程减小,其中单位河长内悬移质全沙的恢复程度在枝城—沙市河段最大、在螺山—汉口河段最小,相差约23倍;(2)含沙饱和度、床沙补给强度以及流量等影响悬沙恢复效率,饱和度恢复效率系数随进口含沙饱和度的增大而减小,随床沙补给强度的增大而增大,床沙补给强度为正时饱和度恢复效率系数随流量的增大而减小、床沙补给强度为负时随流量的增大而增大;(3)基于饱和度恢复效率系数与进口含沙饱和度、流量以及床沙补给强度的关系,建立了计算河段出口悬移质全沙以及各粒径组悬沙含沙量的经验公式。In the riverbed erosion process caused by unsaturated water and under the influence of multiple factors,the process of suspended sediment recovery along the downstream reach of a dam is quite complex.To comprehensively explore the mechanism of suspended sediment recovery,the suspended sediment saturation(SSS)and the saturation recovery efficiency coefficient(SREC)were selected as key parameters to describe the suspended sediment recovery degree and efficiency,respectively.Based on field-measured flow and sediment data for the Yichang—Datong reach,the variation tendency and influencing factors of the SREC were analyzed and described,and empirical equations to quantify the SREC were established.The results revealed that:①In the downstream reaches of the TGR,the SREC shows no consistent variation trend over time,but generally decreased with increasing erosion distance.Among the whole reach,the degree of total suspended sediment recovery per unit river length in the Zhicheng-Shashi reach is the highest,whereas the lowest in the Luoshan—Hankou reach.The former is approximately 23 times more than the latter.②The efficiency of suspended sediment recovery is affected by the inlet SSS,bed material supply intensity and flow discharge.The SREC decreased with increasing inlet SSS and increased with increasing bed material supply intensity.The SREC decreased with increasing flow discharge under a positive bed material supply intensity and increased with increasing flow discharge under a negative bed material supply intensity.③Based on the relationship between the SREC and the influencing factors,i.e.,the inlet SSS,bed material supply intensity and flow discharge,the empirical models for calculating the suspended sediment concentrations in total and each size group were established at the reach outlet.

关 键 词：悬沙恢复 不平衡输沙 含沙饱和度 饱和度恢复效率系数 三峡水库 

分 类 号：TV147[水利工程—水力学及河流动力学]