Study of Critical Values of Sediment Concentration for the Change from Deposition to Erosion in Yangtze Delta

Abstract:

The deposition rate of the delta decreased when seawards sediment decreased. The critical values of sediment concentration mean the concentration which kept balance of erosion and deposition. According to the topography data of Yangtze estuary between 1958 and 2007, the change process of the isobaths is established. Based on the datum line of east longitude 122°17′, the empirical relation between the erosion/deposition rate of delta and the sediment amount was built and the critical values were calculated. The trend of the change of sediment concentration was also forecasted. The isobaths of -10 m, -15 m and -20 m have been eroded from 2000 to 2007 because of the decrease of the sediment discharge into the sea. The critical values of the isobaths of -10m, -15m, -20m is 24.88, 24.23, 20.40 million tons per year and the numbers are decreasing in the deep sea.

• Periodical: Applied Mechanics and Materials (Volumes 212-213)
• Pages: 145-150
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.212-213.145
• Online since: October 2012
• Authors: Yun Ping Yang, Yi Tian Li, Yong Yang Fan, Jian Qiao Han
• Keywords: Critical Values of Sediment Concentration, Estuarine Delta, Trend Forecast

References

[1] Trenhaile A S: Coastal dynamics and Landforms. Oxford: Oxford University Press, 1997.

[2] M.E. Ren: Mans impact on the coastalzone of the Mississippi river delta, Acta geographica sinica, Vol.42(1989), pp.221-230.

[3] Stanley.D.J and Warne.A.G:Nile delta in its destruction phase. Journal of Coastal Research, Vol.14(1998), pp.794-825.

[4] Fanos A M: The impact of human activities on the erosion and accretion of the Nile delta coast. Journal of Coastal Research. Vol.11(1995), pp.821-833.

[5] Z.S. Yang, H.J. WangY.Shao: Phase change of the modern Huanghe River delta evolution since its last end channel shift in 1976(and its phase change). Jarupongsakul T and Saito Y.Oroceedings of 5 International Comference on Asian Marine Geology, AGCP 475 Delta MAP and APN Mega-Delta. January 13-18, 2004, Bangkok, Thailand.

DOI: 10.1016/j.margeo.2021.106516

[6] C.L. Qian: Effects of the water conservancy projects in the luanhe river basin on luanhe river delta hebei province, Acta geographica sinica,Vol.49(1994),pp.158-166.

[7] S.L. YangJ.Zhu, Q.Y. Zhao: A perlimenary study on the influence of Changjiang river sediment supply on subaqueous delta-Evidences in late 20th century and an expectation for the coming decades, Acta oceanlogica sinica, Vol.25(2003),pp.83-94.

[8] P.Li,S.L. Yang, S.B. Dai: Accretion/erosion of the Suobaqueous Delta at the Yangtze Estuary in Recent Years, Acta geographica sinica, Vol.62(2007), pp.707-716.

[9] S.L. YangJ.Zhu, P.Li: Response of Tidal Bank on the Changjiang River Mouth Foreland to Drastic Decline in Riverine Sediment supply and Sea Level rise, Advances in marine science, Vol.23(2005), pp.152-158.

[10] Moore.G.T: Interaction of rivers and oceans: Paleocene petro leupotential,AAPG,Vol.53(1969), pp.452-459.

[11] C.X. Yun: The recent development rules of the Changiang Estuary, (1nd ed , Ocean Press, Bei jing 2004)pp.243-245.

[12] C.X.Li, S.Y. Yang, D.D. Fan, et al: The Change in Changjiang suspended load and its impact on the delta after completion of three-gorges dam, Quaternary Sciences, Vol.24(2004), pp.495-500.

[13] J.J. Fang, Y.T.Li, Z.H. Sun, J.Y. Deng: Analsis of Ronoff change Characteristics at Datong Station of Yangtze River[J], Water Resources and Power, Vol.29(2011), pp.9-13.

[14] C.X. Yun: China River delta crisis, (1nd ed , Ocean Press, Bei jing 2010)pp.10-11.

[15] E.F. Zhang, X.Q. Chen: Changes of Water Discharge between Datong and the Changjiang Estuary during the Dry Season, Acta geographica sinica, Vol.58(2003), pp.231-238.

[16] J.Liu, J.Y. Chen, Z.Y.Xu: River-bed evolution in the braided reach of the south and north passage after implementing Yangtze estuary deepwater navigational improvement, Advances in Water Science, Vol.19(2008), pp.605-612.