三峡蓄水后长江中游典型弯曲河段水动力特性及演变机理  

Evolution characteristics and mechanism of curved reach in the middle reaches of the Yangtze River after impoundment of the Three Gorges Project

作　　者：邓中辉 马奕 DENG Zhong-hui;MA Yi(Changjiang River Administration of Navigational Affairs, M.O.T., Wuhan 430014, China)

机构地区：[1]交通运输部长江航务管理局,武汉430014

出　　处：《水道港口》2022年第2期226-233,共8页Journal of Waterway and Harbor

基　　金：三峡后续工作科研项目(SXHXGZ-2020-4);国家重点研发计划项目(2018YFB1600400)。

摘　　要：针对三峡蓄水后中游部分弯曲河段出现的“凸冲凹淤”新现象,采用二、三维数学模型,对典型弯道段水流动力条件进行全面分析。结果表明,三峡蓄水前后,弯道段不同流量级下水流动力结构并未发生显著调整,中洪水期凸岸边滩水深小、流速大,水流动力较强,相应滩面易于冲刷。三峡蓄水后,中洪水期持续时间延长,加之来沙减小,尤其是有利于凸岸边滩恢复的枯水期含沙量大幅减小,弯道凸岸边滩的稳定性随之有所减弱,导致了部分弯道“凸冲凹淤”现象的出现。研究成果揭示了弯曲河段“凸冲凹淤”现象的水流动力作用机理,将为长江中下游河道治理提供技术支撑。Curved reaches are widespread in middle Yangtze River.Before the Three Gorges reservoir impoundment,the concave bank of curved reaches was scouring while convex bank was silting.After impoundment,it will turn into convex bank erosion and concave bank deposition,which puts forward new problems for river management.In this paper,a two-dimensional mathematical model and a three-dimensional mathematical model were established to calculate the variation laws of the main flow line,bottom velocity,shear stress,circulation intensity and relative circulation intensity of the typical curved reach.The curved reach evolution mechanism under the dam after the impoundment of the Three Gorges reservoir was revealed,which provides support for the waterway regulation technology in middle and lower Yangtze River.

关 键 词：河床演变机理 弯曲河段 凸冲凹淤 数学模型 

分 类 号：U617[交通运输工程—船舶及航道工程]