长江重庆主城区河段卵石推移质走沙条件研究  

Study on transport laws of pebble bed load in Chongqing reach of Yangtze River

作　　者：杨成刚 许全喜 袁晶 董炳江 YANG Chenggang;XU Quanxi;YUAN Jing;DONG Bingjiang(Bureau of hydrology,Changjiang River Water Resources Commission,Wuhan 430010,China)

机构地区：[1]长江水利委员会水文局,湖北武汉430010

出　　处：《人民长江》2020年第7期1-6,12,共7页Yangtze River

基　　金：国家重点研发计划项目(2016YFC0402101);三峡工程泥沙重大问题研究项目(ZZ2018013001F);中国长江三峡集团有限公司科研项目(0704166)。

摘　　要：三峡水库175 m试验性蓄水后,长江重庆主城区河段泥沙输移发生显著改变。研究重庆主城区河段泥沙输移规律,弄清泥沙输移与三峡水库调度之间的联系,对于优化水库调度,减轻库区淤积具有重要意义。依据寸滩站长系列年卵石推移质原型观测资料,结合二维数学模型和卵石推移质起动公式,分析了重庆主城区河段卵石推移质输移特性变化及走沙条件。结果表明:三峡水库蓄水以来,重庆主城区河段卵石推移质输移量显著减少,卵石颗粒细化,走沙时间也大幅缩短;研究河段内卵石推移质起动的临界条件是三峡水库坝前水位低于157 m,上游来流量大于6800 m^3/s,并用2016年实测资料加以验证,验证结果较好。研究表明通过三峡水库调度可以加大重庆主城区河段的泥沙输移强度,减轻该河段内的泥沙淤积。The characteristics of river erosion and siltation have changed significantly in the Chongqing reach of the Yangtze River after the 175 m experimental operation of the Three Gorges Reservoir.Studying the sediment transport law in the Chongqing reach and establishing the relationship between sediment transport and the Three Gorges Reservoir regulation have great significance for reservoir regulation optimization and deposition reduction in the reservoir.Therefore,the transport and starting-conditions of pebble bed load in the Chongqing reach of the Yangtze River were analyzed in this study.Also,the long-series measured data of pebble bed load at Cuntan station,the two-dimensional mathematical model and formula of pebble bed load incipient motion were used in this study.The results showed that since 175 m experimental operation of the Three Gorges Reservoir,the transfer load of pebbles had significantly reduced,the pebble grains had been refined and the transport-time had also been shortened greatly in reach of Chongqing urban.Furthermore,the critical conditions of pebble bed load incipient motion were that the water level in front of the dam was less than 157 m,and the upstream flow was greater than 6800 m^3/s,which was verified by measured data in 2016.It was also found that Three Gorges Reservoir regulation could increase the pebble-bed-load transport and alleviate sedimentation in the Chongqing reach.

关 键 词：水库泥沙 卵石推移质 起动公式 走沙条件 三峡水库调度 重庆主城区河段 

分 类 号：TV698[水利工程—水利水电工程]