Abstract
In recent years, regional floods and typhoons have occurred in the Yangtze Estuary. Changing dynamic conditions and dramatic reduction of sediment discharge in the basin are affecting the dynamic equilibrium pattern of the Yangtze Estuary. Based on the field measurement data and theoretical derivation, this paper analyzed the changing process of runoff-sediment discharge into the sea after the operation of the Three Gorges Project (TGP), and the tidal dynamics and sediment variation characteristics of the Yangtze Estuary. The erosion of South Branch mainly occurs in the channel below −10 m contour, and the riverbed volume below contours 0 m and −10 m has a good correlation with the sediment discharge of Datong Station in the previous year. On this basis, the ratio of the horizontal distance from the starting point to the section centroid below the average water level (Bc) and the water depth at the section centroid (Hc) was proposed to describe the change of the section shape. The relationships between the water-diverting ratio, the sediment-diverting ratio and the water-diverting angle, the conditions of runoff and sediment discharge from the upper reach and the characteristics of the riverway section were established, and the theoretical calculation equations of the water-diverting ratio, the sediment-diverting ratio and the diverting angle of each bifurcation were also established.
References
Cao, S.Y. and Knight, D.W., 1997. Entropy-based design approach of threshold alluvial channels, Journal of Hydraulic Research, 35(4), 505–524.
Chen, J.Y., 2009. Yangtze River Estuary in the 21st Century, China Ocean Press, Bei**g. (in Chinese)
Chen, J.Y., Yun, C.X., Xu, H.G. and Dong, Y.F., 1979. The developmental model of the Chang Jiang River Estuary during last 2000 years, Haiyang Xuebao, 1(1), 103–111. (in Chinese)
Chen, S.S., Li, X., Zou, C.Y. and Zhu, G.W., 2001. An analysis of the changes and evolvements on the foreshore and deep channels of Lingding Bay in Pearl River Estuary in past twenty years, Marine Sciences, 25(6), 52–53. (in Chinese)
Dai, B.K., Lu, C.T., Han, Y.F., Li, R.J. and Luo, X.F., 2021. Riverbed evolution and its influencing factors in the South Branch and the North Branch of the Yangtze River estuary since 1958, Hydro-Science and Engineering, (2), 27–37. (in Chinese)
Dou, G.R., 1964. Riverbed morphology of plain alluvial rivers and tidal estuaries, Journal of Hydraulic Engineering, (2), 1–13. (in Chinese)
Dou, G.R., 1995. Sediment carrying capacity of currents and waves, Chinese Science Bulletin, 40(5), 443–446.
Dou, X.P., Zhang, Z.L., Gao, X.Y., Zhang, X.Z., Ding, L. and Jiao, J., 2020. Analysis on changes of current, sediment and riverbed evolution in Yangtze Estuary for the past 20 years, Proceedings of the 10th International Conference on Asian and Pacific Coasts, 641–647.
Gong, C.L. and Yun, C.X., 2002, Floods rebuilding the riverbed of the Changjiang Estuary, The Ocean Engineering, 20(3), 94–97. (in Chinese)
Guo, L.C., Su, N., Zhu, C.Y. and He, Q., 2018. How have the river discharges and sediment loads changed in the Changjiang River basin downstream of the Three Gorges Dam? Journal of Hydrology, 560, 259–274.
Heritage, G.L., Large, A.R.G., Moon, B.P. and Jewitt, G., 2004. Channel hydraulics and geomorphic effects of an extreme flood event on the Sabie River, South Africa, Catena, 58(2), 151–181.
Hu, C.H., Chen, X.J. and Chen, J.G., 2008. Spatial distribution and its variation process of sedimentation in Yellow River, Journal of Hydraulic Engineering, 39(5), 518–527. (in Chinese)
Jiao, J., Dou, X.P., Gao, X.Y., Ding, L. and Yang, X.Y., 2020. Morphodynamic characteristics and medium-term simulation of the North–South Passage under the impact of the Yangtze Estuary Deepwater Navigation Channel Project, China Ocean Engineering, 34(2), 198–209.
Jiao, J., Yang, X.Y., Ding, L., Huang, Y.M. and Wang, Y.F., 2021. Study on the response law of the riverbed volume of the South Branch of the Yangtze Estuary to the change of discharge and sediment load, The Ocean Engineering, 39(6), 119–125. (in Chinese)
Leopold, L.B. and Langbein, W.B., 1962. The Concept of Entropy in Landscape Evolution, U.S. Government Printing Office, Washington, D.C.
Li, L.X., Pan, Y. and Li, L., 2018. Fractal characteristics and prediction of backsilting quantity in Yangtze Estuary Deepwater Channel, China Ocean Engineering, 32(3), 341–346.
Lin, C.C., 1991. Application of entropy concept in open-channel flow study, Journal of Hydraulic Engineering, 117(5), 615–628.
Ni, J.R. and Zhang, R., 1991. The physical nature of hydraulic geometry, Journal of China Hydrology, (4), 1–6. (in Chinese)
Rinaldo, A., Rodriguez-Iturbe, I. and Rigon, R., 1998. Channel Networks, Annual Review of Earth and Planetary Sciences, 26(1), 289–327.
Yun, C.X., 1983. Scouring and siltation processes of tidal flats of the Yangtze Estuary and sediment exchange between flats and channels, Journal of Sediment Research, (4), 43–52. (in Chinese)
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DOU ** is an editorial board member of China Ocean Engineering and was not involved in the editorial review, or the decision to publish this article. All authors declare that there are no other competing interests.
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This work is financially supported by the Key Laboratory of Estuarine & Coastal Engineering, Ministry of Transport Open Research Program (Grant No. KLECE202001), CRSRI Open Research Program (Grant No. CKWV20221007/KY), the National Natural Science Foundation of China (Grant No. 51979172), Jiangsu Provincial Water Conservancy Technology Project (Grant Nos. 2020002, 2021025, and 2021029), Fundamental Research Funds for Central Public Welfare Research Institutes (Y223002), Innovation Team Project of Estuarine and Coastal Protection and Management (Grant No. Y220013), and the Major Scientific Projects of the Ministry of Water Resources (Grant No. SKS-2022087).
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Ding, L., Jiao, J., Tong, Cf. et al. Study on Volume Variation and Stability of Riverbed in the Yangtze Estuary. China Ocean Eng 37, 433–446 (2023). https://doi.org/10.1007/s13344-023-0036-0
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DOI: https://doi.org/10.1007/s13344-023-0036-0