Coastal Morph Dynamics and Long-term Morphological Modeling: A Review

Saeed Zeinali,Sasan Tavakkol,Nasser Talebbeydokhti,Mojtaba Jandaghian

doi:10.19026/rjees.6.5277

Abstract

In this study, different methods of long-term morphological modeling are briefly reviewed. These methods include input reduction, schematization of flow perturbation induced by bed changes and increase of the morphological time step. In the discussion of schematization, methods like tide-averaging, continuity correction, RAM, online or morphological factor and MORFAC, are presented. In the next discussion, the morphological time step, four methods namely straightforward extrapolation, time-centered extrapolation, lengthening of the tide and extrapolation of sediment transport as a function of bed evolution are discussed. As a conclusion it can be postulated that RAM method and time-centered extrapolation are best methods among the rest.

Highlights

Many estuaries around the world are at the same time economically important links between land and sea, providing access to harbours and inland waterways and valuable natural environments, providing shelter, feeding and breeding grounds and nurseries to a wide variety of species (De Vriend, 2003)
Using the morphological acceleration factor (MORFAC) approach enables numerical simulation of coastal morphological evolution due to waves and currents is possible at time scales of decades (Steijn et al, 1998) and for uniform forces such as a tidal ones, Fig. 3: Flow diagram of 'online' morphodynamic model setup (Hauguel, 1978)
Online approach with morphological factor: The methods above have in common that the morphology is updated relatively infrequently compared to the number of flow time steps per tidal cycle and the number of sediment the bed levels computed after each hydrodynamic time steps by a factor (MORFAC) to enables much faster computation

Summary

Introduction

Many estuaries around the world are at the same time economically important links between land and sea, providing access to harbours and inland waterways and valuable natural environments, providing shelter, feeding and breeding grounds and nurseries to a wide variety of species (De Vriend, 2003). Where, In a tidal flow situation, the velocity and wave fields based on the original bathymetry are stored and when the depth changes, the adapted transport field is computed for a number of time points in the tidal cycle zzbb

Results

Conclusion