Estuaries

, Volume 26, Issue 6, pp 1416–1425

Morphological response of tidal marshes, flats and channels of the Outer Yangtze River mouth to a major storm

Authors

    • State Key Laboratory of Estuarine and Coastal Sediment Dynamics and MorphodynamicsEast China Normal University
  • Carl T. Friedrichs
    • College of William and MaryVirginia Institute of Marine Science
  • Zhong Shi
    • Department of Harbour and Coastal Engineering School of Naval Architecture and Ocean EngineeringShanghai Jiao Tong University
  • Ping-Xing Ding
    • State Key Laboratory of Estuarine and Coastal Sediment Dynamics and MorphodynamicsEast China Normal University
  • Jun Zhu
    • State Key Laboratory of Estuarine and Coastal Sediment Dynamics and MorphodynamicsEast China Normal University
  • Qing-Ying Zhao
    • State Key Laboratory of Estuarine and Coastal Sediment Dynamics and MorphodynamicsEast China Normal University
Article

DOI: 10.1007/BF02803650

Cite this article as:
Yang, S., Friedrichs, C.T., Shi, Z. et al. Estuaries (2003) 26: 1416. doi:10.1007/BF02803650

Abstract

Systematic morphological changes of the coastline of the outer Yangtze River mouth in response to storms versus calm weather were documented by daily surveys of tidal marshes and flats between April 1999 and May 2001 and by boat surveys offshore during this and earlier periods. The largest single event during 1999 to 2001 was Typhoon Paibaian, which eroded the unvegetated tidal flat and lower marsh and led to accretion on the middle-to-upper marsh and in the subtidal channel. The greatest erosion of 21 cm occurred at the border between the marsh and the unvegetated flat due to the landward retreat of the marsh edge during the storm. Strong waves on the flats increased suspended sediment concentration by 10–20 times. On the upper marsh, where the frequency of submergence by astronomical tides is only 3%, Typhoon Paibian led to 4 cm of accretion, accounting for 57% of the net accretion observed over the 2-yr study. Typhoon Paibian led to 4 cm of accretion, accounting for 57% of the net accretion observed over the 2-yr study. Typhoon Paibian and other large storms in the 1990s caused over 50 cm of accretion along the deep axis of the river mouth outlet channel. During calm weather, when hydrodynamic energy was dominated by tides, deposition was centered on the unvegetated flats and lower, marsh with little deposition on the high marsh and erosion in the subtidal channel. Depositional recovery of the tidal flat from typhoon-induced erosion took only several days, whereas recovery of the subtidal channel by erosion took several weeks. A conceptual model for the morphological responses of tidal marshes, flats, and subtidal channels to storms and calm weather is proposed such that sediment continually moves from regions of highest near-bed energy towards areas of lower energy.

Copyright information

© Estuarine Research Federation 2003