As a major project lying in the Changjiang Estuary, Qingcaosha reservoir leads to change of river regime in the North Channel markedly. The change of river regime could induce change of current field and sediment concentration, and then influence bed erosion and deposition. The three-dimensional hydrodynamic and sediment model were used to calculate and analyze the impacts of the project on current filed, sediment concentration, erosion and deposition in area around the reservoir. After the project, width of upper reaches of the North Channel was narrowed, which results in increase of both current speed and sediment concentration in the major channel on the north of Qingcaosha reservoir. On the contrary, the current speed and sediment concentration decrease in areas on east of the reservoir, lower reaches of the North Channel and sand bar due to the decrease of river discharge and tidal prism flowing into the North Channel. Using the formula of bed erosion and deposition based on experience and theory, and the modeled current, sediment concentration and water level, the erosion and deposition caused by reservoir project was calculated. Strong erosion occurs in the North Channel on north of reservoir, with maximum of 3 m, which matches well both in shapes and values with the observed depth change before and after the project. The numerical model simulated the distributions and magnitude of bed erosion and deposition fairly well caused by Qingcaosha reservoir project.
Key words
Changjiang Estuary /
Qingcaosha reservoir /
hydrodynamic /
sediment concentration /
erosion and deposition
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References
[1] LIU Dong-sheng, XIONG Ming, DONG Wei. Channel erosions of the lower Hanjiang before and post Danjiangkou reservoir (in Chinese)[J]. Express Water Resour Hydropower Inf,1998,19(23):23-26.
刘东生,熊明,董伟.丹江口水库下游浑水与清水冲刷特点对比分析[J].水利水电快报,1998,19(23):23-26.
[2] YANG Z, WANG H, SAITO Y, et al. Dam impacts on the Changjiang (Yangtze) River sediment discharge to the sea: The past 55 years and after the Three Gorges Dam[J]. Water Resources Research,2006,42(4):501-517.
[3] LIU Jie, CHEN Ji-yu, LE JIA-hai, et al. Erosion_deposition analyses on the north passage after implementing the first stage project of the Yangtze estuary deepwater channel regulation[J]. Journal of Sediment Research,2004(5):15-22
刘杰,陈吉余,乐嘉海,等.长江口深水航道治理一期工程实施后北槽冲淤分析[J].泥沙研究,2004(5):15-22.
[4] GU Yu-liang, LE Qin, JIN Di-hui. Qingcaosha, Water resource of Shanghai for hundreds of years[J]. Shanghai Construction Science & Technology,2008(1):66-69.
顾玉亮,乐勤,金迪惠.青草沙——上海百年战略水源地[J].上海建设科技,2008(1):66-69.
[5] HUANG Guo-ling, WU Yan. Analysis of river regime change in Qingcaosha water source[C]. China Hydraulic Engineering Society annual meeting, paper collection of human activity and estuary group,2007.
黄国玲,吴焱.青草沙水源地河势演变分析[C].中国水利学会2007学术年会人类活动与河口分会场论文集,2007.
[6] LI Lu, ZHU Jian-rong, WU Hui. Impacts of wind stress on saltwater intrusion in the Yangtze Estuary[J]. Sci China Earth Sci,2012,55(7):1 178-1 192.
[7] LI Lu, ZHU Jian-rong, WU Hui, et al. Lateral saltwater intrusion in the North Channel of the Changjiang Estuary [J]. Estuaries & Coasts,2014,37(1):36-55.
[8] ZHU Jian-Rong, ZHU Shou-xian. Improvement of the ECOM with application to the Changjiang River estuary, Hangzhou Bay and adjacent waters[J]. Oceanologia et Limnologia Sinica,2003,34(4):364-374.
朱建荣,朱首贤.ECOM模式的改进及在长江河口,杭州湾及邻近海区的应用[J].海洋与湖沼,2003,34(4):364-374.
[9] Ocean Album Editor Group. Album of the Bohai Sea, the Yellow Sea and the East China Sea[M]. Beijing: Chian Ocaen Press,1991.
海洋图集编委会.渤海黄海东海海洋图集[M].北京:海洋出版社,1991.
[10] ZHANG Rui, WANG Ya-pin, PAN Shao-ming. Variations of suspended sediment concentrations and loads into the estuary area from Yangtze River in recent 50 years[J]. Marine Science Bulletin,2008,27(2):1-9.
张瑞,汪亚平,潘少明.近50年来长江入河口区含沙量和输沙量的变化趋势[J].海洋通报,2008,27(2):1-9.
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