Modeling the tidal channel morphodynamics in a macro-tidal embayment, Hangzhou Bay, China.

The Hangzhou Bay is a macro-tidal bay located to the south of the Changjiang estuary in China. Along its northern shore, a large-scale tidal channel system has developed, which includes a main northern tidal channel, with a length of more than 50 km and a width up to 10 km, and a secondary southern tidal channel. A process-based morphodynamic model, incorporating the cohesive sediment transport module of Delft3D, is used to analyze the physical processes and mechanisms underlying the formation and evolution of this tidal channel system. The results show that spatial gradients of flood dominance, caused by boundary enhancement via current convergences, is responsible for the formation of the channel system, due to a combination of the various factors such as funnel-shaped geometry hindering associated with the presence of islands, and flow deviation by the southern tidal flat and so on. The model results agree well with the real morphological features. This study also indicates that the reclamation of the southern tidal flat imposes a profound influence on the morphological evolution of the tidal channel system in the Hangzhou Bay. It is feasible to use the model to simulate long-term estuarine morphological changes with cohesive sediment settings.

[1]  E. J. Hayter,et al.  MODELLING COHESIVE SEDIMENT TRANSPORT IN ESTUARIAL WATERS , 1986 .

[2]  A. Spek.  Tidal asymmetry and long-term evolution of Holocene tidal basins in The Netherlands: simulation of palaeo-tides in the Schelde estuary , 1997 .

[3]  M. Stive,et al.  Numerical modelling of shoal pattern formation in well-mixed elongated estuaries , 2003 .

[4]  Delft Hydraulics,et al.  ADVANCES IN MORPHODYNAMICS OF TIDAL RIVERS AND ESTUARIES , 2003 .

[5]  T. M. Parchure,et al.  Erosion of soft cohesive sediment deposits , 1985 .

[6]  G. Stelling,et al.  Development and validation of a three-dimensional morphological model , 2004 .

[7]  Z. B. Wang,et al.  Morphodynamic modelling for a tidal inlet in the Wadden Sea: "Het Friesche Zeegat" , 1995 .

[8]  M. Pejrup,et al.  Modelling of cohesive sediment transport in a tidal lagoon—an annual budget , 2005 .

[9]  Charles A. Simenstad,et al.  Historical changes in the Columbia River Estuary , 1990 .

[10]  D. Schoellhamer,et al.  Cohesive Sediment Transport. II: Application , 1989 .

[11]  Charles A. Nittrouer,et al.  Dispersal of river sediments in coastal seas: Six contrasting cases , 1995 .

[12]  J. Winterwerp,et al.  Turbulent exchange of fine sediments in a tidal channel in the Ems/Dollard estuary. Part II. Analysis with a 1DV numerical model , 2001 .

[13]  Henk M. Schuttelaars,et al.  Initial formation of channels and shoals in a short tidal embayment , 1999, Journal of Fluid Mechanics.

[14]  Su Jilan,et al.  Changjiang river plume and suspended sediment transport in Hangzhou Bay , 1989 .

[15]  X. L. Wang,et al.  Modelling tidal currents in a sediment stratified idealized estuary , 2005 .

[16]  Emmanuel Partheniades,et al.  Erosion and Deposition of Cohesive Soils , 1965 .

[17]  H. D. Vriend,et al.  Initial formation and long-term evolution of channel–shoal patterns , 2004 .

[18]  Y. Wang,et al.  Morphodynamic modelling of open-sea tidal channels eroded into a sandy seabed, with reference to the channel systems on the China coast , 2008 .

[19]  Cc Inglis,et al.  THE LONG-TERM EFFECTS OF TRAINING WALLS, RECLAMATION, AND DREDGING ON ESTUARIES. , 1958 .

[20]  B. Latteux,et al.  Approaches to long-term modelling of coastal morphology : A review , 1993 .

[21]  F. Ahnert,et al.  Estuarine Meanders in the Chesapeake Bay Area , 1960 .

[22]  J. A. Roelvink,et al.  Medium-term 2DH coastal area modelling , 1993 .

[23]  William Roberts,et al.  Dynamics of Estuarine Muds , 2001 .

[24]  Baosheng Wu,et al.  Fluvial processes and morphological response in the Yellow and Weihe Rivers to closure and operation of Sanmenxia Dam , 2007 .

[25]  H. D. Vriend,et al.  Mathematical modelling and large-scale coastal behaviour , 1991 .

[26]  A. J. Mehta,et al.  An Investigation Of The Depositional Properties Of Flocculated Fine Sediments , 1975 .

[27]  C. Teisson,et al.  Cohesive suspended sediment transport: feasibility and limitations of numerical modeling , 1991 .

[28]  M. Nichols,et al.  Evolution of an Urban Estuarine Harbor: Norfolk, Virginia , 1991 .

[29]  K. Dyer,et al.  Coastal and Estuarine Sediment Dynamics , 1986 .

[30]  D. Wal,et al.  Long-term morphological change in the Ribble Estuary, northwest England , 2002 .

[31]  M. van der Wegen,et al.  Long‐term morphodynamic evolution of a tidal embayment using a two‐dimensional, process‐based model , 2008 .

[32]  Yang Zuo-sheng,et al.  Transport and deposition of river sediment in the Changjiang estuary and adjacent continental shelf , 1985 .

[33]  J. Dias,et al.  Numerical modelling of cohesive sediments transport in the Ria de Aveiro lagoon, Portugal , 2006 .

[34]  J. Syvitski,et al.  Geomorphic/Tectonic Control of Sediment Discharge to the Ocean: The Importance of Small Mountainous Rivers , 1992, The Journal of Geology.

[35]  Giovanni Seminara,et al.  Long‐term evolution and morphodynamic equilibrium of tidal channels , 2002 .