Responses of runoffsediment flux and bedform in the Middle Yangtze River to the completion of the Three Gorges Dam

doi:10.3969/j.issn.1000-5641.2016.02.012

Abstract

Abstract: Comparation methods are used to examine the responses of hydrosediment and river bedform after the completion of the Three Gorges Dam. Data are based on the historical data of runoff and sediment discharge (1950—2013) and insite measured data of depth and bedload (2003, 2011). The results demonstrate that the average annual discharge at Yichang and Hankou stations has decreased 10.1% and 7.2% after the Three Gorges Dam completion. The average annual sediment flux of the Yichang and Hankou stations decreased from 556 and 402 Mt/a to 60 and 150 Mt/a, accounted for 89.5% and 62.2% of that have been trapped by the Three Gorges Dam. In addition, the average annual medium diameter of suspended sediment at Yichang and Hankou stations has decreased from 35 \mm and 25 \mm to 4 \mm and 15 \mm, but the bed load has become coarser and coarser. The depth at the thalweg has also increased to 0.4～3.7 m due to the bed erosion after the Three Gorges Dam impoundment.

Key words: completion of the Three Gorges Dam;Middle Yangtze River;response, runoff and sediment processes;dynamical geomorphology

CLC Number:

YUAN Wen-Hao, LI Mao-Tian, CHEN Zhong-Yuan, YIN Dao-Wei, WEI Tao-Yuan. Responses of runoffsediment flux and bedform in the Middle Yangtze River to the completion of the Three Gorges Dam[J]. Journal of East China Normal University(Natural Sc, 2016, 2016(2): 90-100.

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