铁板洲顺直分汊河段冲淤调整态势的多方法判断研究  

Multi-method Assessment on the Scouring and Silting Adjustments of Tiebanzhou Straight Braided Channel

作　　者：刘俊宏 陈立[1] 杨莹[1] 马晨煜 刘燃[2] LIU Jun-hong;CHEN Li;YANG Ying;MA Chen-yu;LIU Ran(State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,Hubei Province,China;China Railway Major Bridge Reconnaissance&Design Institute Co.,Ltd.,Wuhan 430050,Hubei Province,China)

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 [2]中国中铁大桥勘测设计院集团有限公司,湖北武汉430050

出　　处：《中国农村水利水电》2025年第4期1-6,13,共7页China Rural Water and Hydropower

基　　金：国家自然科学基金长江联合基金重点项目(U2340217)。

摘　　要：三峡水库蓄水后,枢纽下游分汊河段在不饱和挟沙水流作用下发生长时段冲淤调整,主支汊的分流比发生复杂变化,依据实测资料,采用不同方法判断汊道冲淤调整方向,为分汊河段防洪规划、两岸经济发展布局规划等提供支撑极为重要。以长江干流武汉河段铁板洲分汊段为例,采用主支汊过流面积变化分析、实测分流比变化分析以及河工模型试验相结合的方法,对三峡水库蓄水后该分汊段主支汊的冲淤调整方向进行多方法判断。结果表明:①3种方法对铁板洲顺直分汊河段冲淤调整态势的判断定性上具有一致性,即铁板洲分汊段总体呈支汊冲刷发展,支汊的过流面积占比增加,分流比增大,主汊分流比减小;②支汊来沙不饱和度超过主汊和径流过程调平是铁板洲分汊段支汊冲刷发展的主要原因;③主支汊过流面积变化、实测分流比变化和河工模型试验法均可以定性判断主支汊冲淤变化方向,而河工模型试验法还可以定量给出分汊河段同流量分流比的变化,三峡水库蓄水以来,大水至枯水不同流量级下支汊分流比增加7.4%~13.4%。After the impoundment of the Three Gorges Reservoir,the braided river reaches downstream of the dam have undergone significant long-term scouring and silting adjustments under the condition of unsaturated sediment-laden flow.These changes have resulted in increased complexity in the diversion ratios of the main branch and tributary channels.It is extremely important to use different methods to assess the direction of scouring and silting adjustments in braided channels based on measured data,which provides support for effective flood control planning and the strategic layout of economic development.This paper takes the Tiebanzhou bifurcation section of the Middle Yangtze River in Wuhan as an example,using a combination of multiple methods including flow area change analysis,measured diversion ratio change analysis and river model experiment to assess the direction of scouring and silting adjustments after the operation of the Three Gorges Reservoir.Results show:①All three methods yield consistent qualitative judgments regarding the scouring and silting adjustments in Tiebanzhou straight braided channel,specifically,the minor branch of the channel has generally undergone scouring development,with an increase in the flow area proportion and diversion ratio of the minor branch,while the diversion ratio of the main branch has decreased.②The primary reasons contributing to the scouring development of the minor branch in Tiebanzhou straight braided channel are the sediment unsaturation in the minor branch exceeding that of the main branch and the leveling of the runoff process.③All three methods are effective in qualitatively assessing the direction of scour and silt in Tiebanzhou straight braided channel.Additionally,the river model experiment can offer valuable quantitative insights,particularly regarding changes in the diversion ratio at the same flow rate.Since the impoundment of the Three Gorges Reservoir,the diversion ratio in the minor branch has increased by 7.4% to 13.4% under different flow regimes,rang

关 键 词：铁板洲顺直分汊段 主支汊 冲淤调整 多方法 

分 类 号：TV147[水利工程—水力学及河流动力学]