摘要
为定量研究大型水库运用对河口尾闾河道出汊的影响,以黄河口尾闾段为研究对象提出了一种基于改进熵权法的河道出汊阈值确定方法,根据实测水沙资料确定了尾闾河道出汊指标计算公式及相应的河道出汊阈值,在还原无小浪底工程时尾闾段水沙及河槽形态调整过程的基础上,结合出汊阈值对比分析了有、无小浪底工程时尾闾段发生河道出汊概率的差异。结果表明:河段河相系数和汛期平均水流冲刷强度分别为边界和水沙条件中对河道出汊贡献最大的两个指标;黄河口尾闾段河道出汊阈值为38.16,当出汊指标大于38.16时尾闾段发生河道出汊;小浪底工程运用约束了进入尾闾段的沙量,河道出汊概率明显减小。
In order to quantitatively study the effects of the Xiaolangdi Reservoir on the channel avulsion of the tail reach of the Yellow River estuary,a method for determining the avulsion threshold was proposed based on the improved entropy weight method.According to the meas-ured flow-sediment data,the avulsion threshold index calculation equation and the corresponding channel avulsion threshold in the tail reach of the Yellow River estuary were determined,on the basis of restoring the adjustment process of flow and sediment and the channel morpholo-gy when there was no Xiaolangdi Reservoir,and combined with the avulsion threshold,the difference in the probability of the channel avul-sion in the tail reach of the Yellow River estuary with and without the Xiaolangdi Reservoir was compared and analyzed.The results show that the river facies coefficient and fluvial erosion intensity are the two dominant indicators in the boundary and flow-sediment conditions respec-tively.Based on the measured data,the avulsion threshold index calculation equation established by these two dominant indicators,and the avulsion threshold of the tail reach of the Yellow River estuary is obtained as 38.16,that is,when the avulsion threshold index is greater than 38.16,the channel avulsion occurs in the tail reach.The application of the Xiaolangdi Reservoir restricts the amount of sediment entering into the tail reach of the Yellow River estuary,and the probability of the channel avulsion is significantly reduced.
作者
杨卓媛
夏军强
宋红波
刘国强
YANG Zhuoyuan;XIA Junqiang;SONG Hongbo;LIU Guoqiang(Changjiang Survey,Planning,Design and Research Co.,Ltd.,Wuhan 430010,China;State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,China;Hubei Key Laboratory of Basin Water Security,Wuhan 430010,China)
出处
《人民黄河》
CAS
北大核心
2024年第4期37-42,共6页
Yellow River
基金
国家重点研发计划项目(2021YFC3200202)。
关键词
河道出汊阈值
水沙条件
河床调整
黄河口尾闾段
小浪底水库
channel avulsion threshold
flow and sediment regime
channel adjustments
tail channel of the Yellow River estuary
Xiaolangdi Reservoir
