三峡建坝后长江宜昌—汉口河段水沙与河床的应变

发布时间：2019-04-23 14:58

【摘要】：通过三峡建坝前后1950—2013年的水文、泥沙与2003年和2011年的实测河床底形资料对比,试图讨论长江中游宜昌—汉口河段水沙及河床地形等应变量对三峡建坝的响应,为人们理解河流水沙及河床冲淤对超大型水库应变的幅度提供具体案例.三峡建坝后,宜昌站和汉口站年均流量由建坝前的13 850 m3/s和22 650 m3/s(1950—2002)减少到建坝后的12 450m3/s和21 000 m3/s(2003—2013),分别减少10.1%和7.2%;年均输沙量由5.56亿t和4.02亿t(1950—2002)锐减至0.6亿t和1.5亿t(2003—2013),分别减少89.5%和62.2%;年均悬沙中值粒径则由35μm(1950—2002)和25μm(1955—1975)减少至4μm和15μm(2003—2010).同时,水流挟沙不饱和能力的增加,引起了河床的沿程冲刷及泥沙粗化,宜枝河段、荆江河段和城汉河段深泓处分别平均冲刷了3.7 m、1.5 m和0.4 m,在主槽刷深的同时,河道浅滩有不同程度的萎缩.三峡建坝已导致中游水沙及冲淤条件发生了巨大改变.
[Abstract]:Based on the comparison of the hydrologic and sediment data from 1950 to 2013 before and after the dam construction of the three Gorges Project and the measured river bed bottom profile data in 2003 and 2011, this paper attempts to discuss the response of the water, sediment and riverbed topography of the Yichang-Hankou reach of the middle reaches of the Yangtze River to the dam construction of the three Gorges Project. It provides a concrete example for people to understand the strain range of river water and sediment and river bed scouring and silting on super-large reservoirs. After the dam construction, the annual discharge of Yichang station and Hankou station decreased from 13,850m3 / s and 22650m3 / s (1950 / 2002) to 12 450m3/s and 21,000 m3 / s (2003 / 2013), which decreased by 10.1% and 7.2%, respectively, while the annual discharge of Yichang and Hankou stations decreased from 13,850m ~ 3 / s and 22,650m ~ 3 / s (1950 / 2002) respectively. The annual sediment transport decreased sharply from 556 million t and 402 million t (1950 t) to 60 million t and 150 million t (2003 / 2013), which decreased by 89.5% and 62.2%, respectively. The mean particle size of suspended sediment decreased from 35 渭 m (1950 渭 m) and 25 渭 m (1955 / 1975) to 4 渭 m and 15 渭 m (2003 / 2010). At the same time, the increase of the unsaturated capacity of water flow leads to the erosion and coarsening of the riverbed along the river bed. The average scour of Yizhi River, Jingjiang reach and Chenghan reach is 3.7 m, 1.5 m and 0.4 m, respectively. In the main channel brush depth, the river shoal has varying degrees of shrinkage. The dam construction of the three Gorges has led to a great change in the water, sediment and scouring conditions in the middle reaches of the three Gorges.
【作者单位】：华东师范大学地球科学学部;
【基金】：长江中下游典型大坝水库泥沙淤积过程中溶解硅滞留行为探究(41271520)
【分类号】：TV147

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