三峡水库蓄水后宜昌枯水位的时变特征及成因

发布时间：2018-05-06 18:33

  本文选题：坝下游 + 枯水位　； 参考：《水利水运工程学报》2017年04期

【摘要】：三峡水库蓄水后,葛洲坝枢纽下游近坝河段内枝城枯水位降幅较小,但宜昌及宜都等位置枯水位降幅较大,且随时间变化显示出非均匀下降的特征。为揭示该现象成因,依据宜昌至枝城河段内枯水位、地形、河床组成等实测资料分析了各因素的时变特征,并采用分离变量法计算分析了枯水位非均匀下降的机理。结果表明:宜昌枯水位在2008年前降幅小且下降速度慢,2008年以后降幅增大且下降速度加快;宜都至枝城区间冲刷是引起宜昌枯水位下降的主导因素,宜都以上河床变形、枝城水位下降为次要因素;宜都以上河床粗化引起阻力调整,是导致2008年前宜昌枯水位降幅小的主要原因;2012年后,宜昌至枝城段河床变形和阻力调整余地都已不大,未来宜昌枯水位稳定性主要取决于枝城水位变幅。
[Abstract]:After the three Gorges Reservoir impounded, the water level of Zhicheng in the lower reaches of Gezhouba Project decreased slightly, but the water level of Yichang and Yidu decreased more and more, and the variation of the water level showed the characteristics of non-uniform decline with time. In order to reveal the cause of the phenomenon, the time-varying characteristics of the factors are analyzed based on the measured data of the dry water level, topography and river bed composition in the reach of Yichang to Zhicheng River, and the mechanism of the uneven decline of the dry water level is calculated and analyzed by using the method of separating variables. The results show that the decline of the dry water level in Yichang is small and slow before 2008, and the decrease is increasing and the decreasing speed is quickening after 2008, the erosion between Yidu and Zhicheng is the main factor that causes the decline of the low water level in Yichang, and the deformation of the riverbed above Yidu, The water level in Zhicheng is a secondary factor; the resistance adjustment caused by the coarsening of the riverbed above Yidu is the main reason leading to a small decrease in the dry water level before 2008; after 2012, the bed deformation and resistance of the section from Yichang to Zhicheng have been limited. In the future, the stability of water level in Yichang mainly depends on the variation of water level in Zhicheng.
【作者单位】： 武汉大学水资源与水电工程科学国家重点实验室;
【基金】：国家科技支撑计划课题(2013BAB12B02) 国家自然科学基金资助项目(51579185,51339001)
【分类号】：TV147
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本文编号：1853405