三峡工程运行后水库下游弯曲河道演变规律  

Evolution Law of Curved River Channel Downstream of Reservoir After Operation of Three Gorges Project

作　　者：郭小虎[1] 唐峰[1] 陈栋[1] 邓彩云[1] GUO Xiao-hu;TANG Feng;CHEN Dong;DENG Cai-yun(Key Laboratory of River and Lake Management and Flood Control in the Middle and Lower Reaches of the Yangtze River of MWR,Yangtze River Scientific Research Institute,Wuhan 430010,China)

机构地区：[1]长江科学院水利部长江中下游河湖治理与防洪重点实验室,湖北武汉430010

出　　处：《水电能源科学》2023年第6期26-30,共5页Water Resources and Power

基　　金：长江水科学研究联合基金(U2240206,U2240224);三峡后续工作总体规划项目(CKSG2021257/HL)。

摘　　要：三峡工程运行后水库下游河道水沙过程发生较大改变,引起弯曲型河道演变规律调整,对河势稳定、防洪安全等可能产生不利影响。基于实测资料分析了三峡工程运行后水库河道下游典型弯道演变规律及其主要动因。结果表明,三峡工程运行后水库下游典型弯道段均出现“切滩”,其主要原因是进入各河段的泥沙尤其是细颗粒沙量大幅减少;而下荆江绝大多数弯道段出现“撇弯”的主要原因为月均径流量过程变异系数较大、弯道段本身弯曲半径较小。随着长江上游干支流梯级水库陆续运行,预计水库下游各河段月均径流量过程变异系数将继续增大,将可能引起目前未发生“撇弯”但弯曲半径相对较小的弯道段发生“撇弯”。After the operation of the Three Gorges Project,the process of water and sediment in the lower reaches of the reservoir changed greatly and led to the adjustment of the evolution law of the curved channel,which may have ad-verse effects on the stability of the river and the safety of flood control.Based on the measured data,the evolution law of the typical bends in the lower reaches of the reservoir and its main causes were analyzed.The results show that after the operation of the Three Gorges Project,the typical bends in the lower reaches of the reservoir all appear"cutting beaches",and the main reason is that the sediments enter each river reaches.The amount of sand,especially fine-grained sand,has been greatly reduced.The main reasons for the"skipping bends"in most of the bends in the Lower Jingjiang are that the variation coefficient of the monthly average runoff process is large and the bending radius of the bends itself is small.With the successive operation of cascade reservoirs in the main and tributaries of the upper reaches of the Yangtze River,it is expected that the variation coefficient of the monthly average runoff process in the lower reaches of the reservoir will con-tinue to increase,which may lead to the occurrence of bends with relatively small bending radius that do not currently have"skipping bends".

关 键 词：三峡工程 水库下游 弯曲河道 演变规律 

分 类 号：TV147[水利工程—水力学及河流动力学]