Morphodynamic responses of a silt-muddy coast to harbor constructions during a major storm event
Abstract
Silt-muddy coast, generally with fine sediment and mild slope, can be strongly influenced by the wave-current-surge interactions during extreme weather conditions, and thus experiences significant morphological changes. In this study, a hydro- and morpho-dynamics Delft3D model is applied to the Huanghua-Binzhou silt-muddy coast, southwest of Bohai Bay, China, to re-evaluate local morphodynamic processes during a major storm event in 10-13th October, 2003. The storm caused a severe sediment siltation in waterway with a value of 9.7x106 m3, therefore, coastal structures were constructed to maintain its water depth. The model results indicate that the strong wind-wave has a relatively wide surfzone due to the mild slope and it plays a critical role in the local morphological change ascribed to its dominance in the maximum bed shear stress. It is notice that tidally-varying water depth and current can affect the significant wave height of wind-wave differently, so that result in distinct responses of bed evolution associated with maximum bed shear stress. The large-scale constructions of Huanghua-Binzhou Harbor form a semi-closed region between the two harbors where local residual current strictly flows along the coastline and results in a low speed zone in the middle accompanied with accretion. In addition, the extremely long jetties cause the wind-wave break in advance in offshore so that weaken coastal hydrodynamics. In combination with the reduction of sediment load by reclamation, the Huanghua-Binzhou silt-muddy coast appears to be more stable in the extreme weather conditions.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMEP11E2077S
- Keywords:
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- 3020 Littoral processes;
- MARINE GEOLOGY AND GEOPHYSICS;
- 4315 Monitoring;
- forecasting;
- prediction;
- NATURAL HAZARDS;
- 4316 Physical modeling;
- NATURAL HAZARDS;
- 4217 Coastal processes;
- OCEANOGRAPHY: GENERAL