摘要
三峡工程运用后,受上游来沙减少及水库拦沙影响,下泄沙量急剧减少,坝下游宜枝河段发生显著冲刷,平滩河槽形态也相应调整。由于宜昌及宜都河段在河型、河床组成上略有不同,且不同断面的河槽形态沿程变化较大,故采用基于河段平均的方法,分别计算了这两河段2002-2013年的平滩河槽形态参数。计算结果表明:研究时段内两河段的平滩河宽总体变化很小;但宜昌段平滩水深约增加1.3m,而宜都段平均冲深达2.9m;两河段的平滩面积均呈持续增加趋势。在此基础上,建立了河段尺度的平滩河槽形态参数与前5年平均的汛期水流冲刷强度之间的经验关系,用于预测该河段平滩河槽形态的调整趋势。
Sediment.load entering the Yizhi Reach of the Yangtze River has been greatly reduced because of the operation of the TGP （Three Gorges Project） , as well as the reduction of the upstream incoming sediment load. Significant processes of channel degradation have occurred along the reach, with the corresponding adjustments in the bankfull channel geometry. Due to the differences of channel pattern and bed form between Yichang and Yidu reaches and the significant longitudinal variability in the cross-sectional geometry, a reachaverage method is adopted to calculate the reach-scale bankfull channel dimensions in these two reaches annu- ally from 2002 to 2013. Calculated results indicate that the reach-scale bankfull widths of these two reaches changed slightly, and the reach-scale bank-full depths in the Yichang and Yidu Reaches increased by 1.3 m and 2.9m, respectively, which led to an obvious increase in the reach-scale bankfull area in each reach. Finally, empirical relationships for the Yichang Reach and Yidu Reach were developed between the reach-scale bankfull channel dimensions and the previous five-year average fluvial erosion intensity during flood seasons, which can be used to predict the adjustment tendency of the reach-scale bankfull geometry.
出处
《泥沙研究》
CSCD
北大核心
2016年第2期14-19,共6页
Journal of Sediment Research
基金
国家自然科学基金资助项目(51079103
51339001
51579186)
关键词
平滩河槽形态
水沙条件
宜枝河段
河床调整
三峡工程
bankfull channel geometry
flow and sediment regime
Yizhi Reach
channel adjustment
Three Gorges Project
作者简介
周美蓉（1992-），女，浙江衢州人，硕士研究生，主要从事河流动力学研究。E-mail：ZMR@whu．edu．cn
