黄河调水调沙影响下的现行三角洲叶瓣冲淤演化格局

    EVOLUTION OF ACTIVE YELLOW RIVER (HUANGHE) DELTA UNDER THE WATER AND SEDIMENT REGULATION SCHEME (WSRS)

    • 摘要: 基于1986—2013年的黄河水文泥沙资料,研究了黄河实施调水调沙以来入海泥沙在通量和粒度组成上的变化特征,揭示了调水调沙影响下黄河入海泥沙通量增加、悬沙粒径粗化的趋势。从2002年调水调沙实施后,现行黄河三角洲叶瓣由侵蚀转为淤积,现行河口处淤积明显,逐渐形成一个饱满的“楔子”。然而,随着调水调沙的持续冲刷,下游河床逐渐粗化,2006年以后径流的冲刷效率不断降低,入海泥沙通量持续降低、悬沙粒径变细。若维持目前调水调沙流量不变,现行黄河三角洲叶瓣造陆速率将逐渐减缓,甚至可能出现蚀退。

       

      Abstract: Based on the datasets collected from Landsat images and the water and sediment data from the Lijin station in the period of 1996 to 2013, the evolution of the active Yellow River delta under the influence of the Water and Sediment Regulation Scheme (WSRS) are investigated. The result indicates that, after the WSRS, the subaerial delta accreted slowly due to the sediment accumulation in the nearshore area after the dam-regulation. Along with the continuous implementations of WSRS, however, the river bed sediments in the lower reaches are increasingly coarser than ever, resulting in the continuous increase in the critical energy for resuspension of the riverbed sediment. Thus the lower channel could no longer supply coarser sediment to the sea; therefore we speculate the critical sediment load for maintainance of the present delta lobe should increase in the future.

       

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