刘杰,程海峰,韩露,等. 流域水沙变化和人类活动对长江口河槽演变的影响[J]. 水利水运工程学报,2021(2):1-9. doi: 10.12170/20200313001
引用本文: 刘杰,程海峰,韩露,等. 流域水沙变化和人类活动对长江口河槽演变的影响[J]. 水利水运工程学报,2021(2):1-9. doi: 10.12170/20200313001
(LIU Jie, CHENG Haifeng, HAN Lu, et al. New trends of river channel evolution of the Yangtze River estuary under the influences of inflow and sediment variations and human activities[J]. Hydro-Science and Engineering, 2021(2): 1-9. (in Chinese)). doi: 10.12170/20200313001
Citation: (LIU Jie, CHENG Haifeng, HAN Lu, et al. New trends of river channel evolution of the Yangtze River estuary under the influences of inflow and sediment variations and human activities[J]. Hydro-Science and Engineering, 2021(2): 1-9. (in Chinese)). doi: 10.12170/20200313001

流域水沙变化和人类活动对长江口河槽演变的影响

New trends of river channel evolution of the Yangtze River estuary under the influences of inflow and sediment variations and human activities

  • 摘要: 基于1998—2016年长江口系列水下地形等有关资料,研究了流域减沙和人类活动对长江口河槽冲淤演变的影响趋势。结果表明:近20年长江口滩槽格局总体稳定,但南支以下河槽呈现由净淤积向净冲刷转变,口内的河槽冲刷、容积扩大,口外的航道拦门沙浅滩长度缩短。河口边滩圈围、江中沙洲人工守护及三峡工程的拦洪消峰作用促使长江口滩槽格局的稳定,而流域来沙减少与河口促淤圏围则促进南支以下河槽由净淤积向净冲刷转变。2002—2003年基本为长江口南支以下河槽冲淤转变的分界点,河口冲淤转变对应的流域年输沙量临界值约2.54亿t。未来,长江流域来沙量可能长期维持在临界值以下的较低水平,长江口将呈现岸滩槽地貌格局稳定条件下的缓慢冲刷趋势。

     

    Abstract: Based on a series of bathymetric data from 1998 to 2016, the new trends of river channel evolution of the Yangtze River estuary under the influences of inflow and sediment variations and human activities are studied. The results show that in the past 20 years, the channel morphology of the Yangtze River estuary has been generally stable, but the downstream channel of the south branch has changed from net siltation to net scour, the channel of the estuary has been scoured and the volume has been expanded, and the length of the channel bar shoal outside the estuary has been shortened. The stability of channel morphology is promoted by the estuary beach enclosure, artificial protection of sandbank in the middle of the river and the flood control and peak elimination of the Three Gorges project. The decrease of sediment and estuary beach enclosure promote the transformation from net siltation to net scour in the downstream channel of the south branch. 2002 and 2003 were basically the time node of the transformation, which corresponds to about 254 million tons of annual sediment transport. In the future, the fluvial sediment is likely to remain at a low level below the critical value for a long time, and the Yangtze River estuary will maintain a slow erosion trend under the stable channel morphology.

     

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