Predicting long-term and short-term tidal flat morphodynamics using a dynamic equilibrium theory
Hu, Z.; Wang, Z.B.; Zitman, T.J.; Stive, M.J.F.; Bouma, T.J. (2015). Predicting long-term and short-term tidal flat morphodynamics using a dynamic equilibrium theory. J. Geophys. Res. Earth Surface, 120(9): 1803-1823. https://dx.doi.org/10.1002/2015JF003486
In: Journal of Geophysical Research. American Geophysical Union: Richmond. ISSN 0148-0227; e-ISSN 2156-2202, more
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| Keywords |
Marine/Coastal; Brackish water |
| Author keywords |
bed shear stress;sediment concentration;ESTMORF model;hydrodynamic simulations;storm events;SED sensors |
| Authors | | Top |
- Hu, Z., more
- Wang, Z.B., more
- Zitman, T.J.
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- Stive, M.J.F.
- Bouma, T.J., more
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| Abstract |
Dynamic equilibrium theory is a fruitful concept, which we use to systematically explain the tidal flat morphodynamic response to tidal currents, wind waves, sediment supply, and other sedimentological drivers. This theory stems from a simple analytical model that derives the tide- or wave-dominated tidal flat morphology by assuming that morphological equilibrium is associated with uniform bed shear stress distribution. Many studies based on observation and process-based modeling tend to agree with this analytical model. However, a uniform bed shear stress rarely exists on actual or modeled tidal flats, and the analytical model cannot handle the spatially and temporally varying bed shear stress. In the present study, we develop a model based on the dynamic equilibrium theory and its core assumption. Different from the static analytical model, our model explicitly accounts for the spatiotemporal bed shear stress variations for tidal flat dynamic prediction. To test our model and the embedded theory, we apply the model for both long-term and short-term morphological predictions. The long-term modeling is evaluated qualitatively against previous process-based modeling. The short-term modeling is evaluated quantitatively against high-resolution bed-level monitoring data obtained from a tidal flat in Netherlands. The model results show good performances in both qualitative and quantitative tests, indicating the validity of the dynamic equilibrium theory. Thus, this model provides a valuable tool to enhance our understanding of the tidal flat morphodynamics and to apply the dynamic equilibrium theory for realistic morphological predictions. |
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