Behavior of Suspended Sediment in the Changjiang Estuary in Response to Reduction in River Sediment Supply

被引:9
|
作者
Zhu, Wenwu [1 ,2 ]
Li, Jiufa [1 ]
Sanford, Lawrence P. [2 ]
机构
[1] E China Normal Univ, State Key Lab Estuarine & Coastal Res, Shanghai 200062, Peoples R China
[2] Univ Maryland, Ctr Environm Sci, Horn Point Lab, Cambridge, MD 21613 USA
基金
美国国家科学基金会;
关键词
Suspended sediment concentration; Sediment resuspension; River sediment reduction; Three Gorges Dam; Changjiang estuary; YANGTZE-RIVER; NILE DELTA; DEPOSITION; TRANSPORT; EROSION; IMPACT; FLUX;
D O I
10.1007/s12237-014-9929-8
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
The Changjiang river sediment supply has decreased dramatically since 2003 when the Three Gorges Dam (TGD) began operation. Annually repeated cruises were conducted in the Changjiang estuary between 2002 and 2011 to examine the behavior of suspended sediment in response to the reduction in river sediment supply. Changes in the Changjiang estuary were not as clear as in the river and showed spatial and temporal variations. Generally, the suspended sediment concentration (SSC) in different channels showed different change characteristics. In the South Branch, furthest upstream, SSC showed no obvious changes for several years after the TGD started to operate in 2003 but then has been decreasing since 2009. In the South Channel, further downstream, SSC showed no obvious responses to the reduction of river sediment supply as of 2011. In the North Channel, SSC seems to have been decreasing slightly in recent years, though not as obviously as in the South Branch. Tidal resuspension contributed to temporal variability in SSC significantly and increased relatively at all stations. Vertical variations in particle size and texture in the South Branch in 2011 indicated very active exchange between the bed and the water column throughout a tidal cycle. The primary response of suspended sediment in the upper Changjiang estuary to the closing of the TGD in 2003 seems to be a lagged decrease in the fine fraction of suspended sediment. This conclusion is supported by multiple lines of evidence. Bulk settling velocities increased, riverine SSC and background SSC at slack tides decreased, and resuspension and deposition lags of SSC relative to current speed decreased. This response was strongest in the South Branch, moderate in the North Channel, and not yet apparent in the South Channel, indicating that the changes are still ongoing.
引用
收藏
页码:2185 / 2197
页数:13
相关论文
共 50 条
  • [31] SUSPENDED SEDIMENT AND NUTRIENTS BUDGETS FOR THE TIDAL POTOMAC RIVER AND ESTUARY
    BENNETT, JP
    ESTUARIES, 1981, 4 (03): : 293 - 293
  • [32] COAGULATION AND SETTLING OF SUSPENDED SEDIMENT IN THE JIAOJIANG RIVER ESTUARY, CHINA
    LI, Y
    WOLANSKI, E
    XIE, QC
    JOURNAL OF COASTAL RESEARCH, 1993, 9 (02) : 390 - 402
  • [33] Intratidal and neap-spring variations of suspended sediment concentrations and sediment transport processes in the North Branch of the Changjiang Estuary
    Zhanhai Li
    Michael Z. Li
    Zhijun Dai
    Fangfang Zhao
    Jiufa Li
    Acta Oceanologica Sinica, 2015, 34 : 137 - 147
  • [34] Flood-ebb asymmetry in current velocity and suspended sediment transport in the Changjiang Estuary
    LI Zhanhai
    WANG Yaping
    CHENG Peng
    ZHANG Guoan
    LI Jiufa
    ActaOceanologicaSinica, 2016, 35 (10) : 37 - 47
  • [35] Suspended sediment exchange between the Changjiang Estuary and Hangzhou Bay and their key driving mechanisms
    Huang, Ju
    Zhu, Jianrong
    Su, Jingwen
    Han, XiangJu
    Cai, Lei
    ESTUARINE COASTAL AND SHELF SCIENCE, 2024, 305
  • [36] Intratidal and neap-spring variations of suspended sediment concentrations and sediment transport processes in the North Branch of the Changjiang Estuary
    Li Zhanhai
    Li, Michael Z.
    Dai Zhijun
    Zhao Fangfang
    Li Jiufa
    ACTA OCEANOLOGICA SINICA, 2015, 34 (01) : 137 - 147
  • [37] Dry-season variability in suspended sediment concentrations in the South Passage of the Changjiang Estuary
    Zhang, Wenxiang
    Yang, Shilun
    Zhu, Jun
    Gong, Shiliang
    Ding, Pingxing
    INTERNATIONAL JOURNAL OF SEDIMENT RESEARCH, 2007, 22 (03) : 199 - 207
  • [39] Flood-ebb asymmetry in current velocity and suspended sediment transport in the Changjiang Estuary
    Zhanhai Li
    Yaping Wang
    Peng Cheng
    Guoan Zhang
    Jiufa Li
    Acta Oceanologica Sinica, 2016, 35 : 37 - 47
  • [40] Intratidal and neap-spring variations of suspended sediment concentrations and sediment transport processes in the North Branch of the Changjiang Estuary
    LI Zhanhai
    LI Michael Z
    DAI Zhijun
    ZHAO Fangfang
    LI Jiufa
    ActaOceanologicaSinica, 2015, 34 (01) : 137 - 147