Erosion Behavior of Sand-Silt Mixtures: Revisiting the Erosion Threshold

The erosion threshold, beyond which bed sediments start to move, is a key parameter describing sediment transport processes. For silt-dominated mixtures, in which the grain size is between sand and clay, existing experimental studies exhibit contradictory observations. That is, the erosion was either sand-like or clay-like, suggesting...

Aggregated morphodynamic modelling of tidal inlets and estuaries

Aggregation is used to represent the real world in a model at an appropriate level of abstraction. We used the convection-diffusion equation to<br/>examine the implications of aggregation progressing from a three-dimensional (3D) spatial description to a model representing a system as a<br/>single box that exchanges sediment with the adjacent...

Dynamics of a Tidal Current System in a Marginal Sea: A Case Study of the Yellow Sea, China

Tidal currents belong to the main driving forces shaping the bathymetry of marginal seas. A globally unique radial sand ridge field exists in the South Yellow Sea off the central Jiangsu coast, China. Its formation is related to the distinctive “radial tidal current” pattern at that location. A generally accepted hypothesis is that the ...

A Morphodynamic Modeling Study on the Formation of the Large‐Scale Radial Sand Ridges in the Southern Yellow Sea

The radial sand ridges (denoted as “RSRs” hereafter) in the Southern Yellow Sea, China, are morphologically striking because of the remarkable size and radial planar orientation, standing out as a unique coastal geomorphology among the worldwide sand ridge systems. The formation of this giant fan‐shaped geomorphic feature requires delicate...

Modelling tidal-induced sediment transport in a sand-silt mixed environment from days to years: Application to the Jiangsu coastal water, China

In the present study a new multi-fractional, depth-averaged sediment transport module was developed and embedded into a morphodynamic model for a sand-silt mixed shallow water environment. Subsequently, the model was applied to the case of the Jiangsu coast, which features a silt enriched sedimentary environment bordered by two large-scale...

Exploratory morphodynamic hindcast of the evolution of the abandoned Yellow River delta, 1578-1855

The Abandoned Yellow River Delta (AYD), which formed when the Yellow River flowed into the Southern Yellow Sea between 1128 and 1855 AD, is a representative example of the sensitivity of deltas to modifications in their environments. In this study, we established a process-based morphodynamic model to explore the morphological evolution of one...

Development and Extension of An Aggregated Scale Model: Part 1 – Background to ASMITA

Whilst much attention has been given to models that describe wave, tide and sediment transport processes in sufficient detail to determine the local changes in bed level over a relatively detailed representation of the bathymetry, far less attention has been given to models that consider the problem at a much larger scale (e.g. that of...

Predicting long-term and short-term tidal flat morphodynamics using a dynamic equilibrium theory

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...

Windows of opportunity for salt marsh vegetation establishment on bare tidal flats: The importance of temporal and spatial variability in hydrodynamic forcing

Understanding the mechanisms limiting and facilitating salt marsh vegetation initial establishment is of widespread importance due to the many valuable services salt marsh ecosystems offer. Salt marsh dynamics have been investigated by many previous studies, but the mechanisms that enable or disable salt marsh initial establishment are still...

Hydrodynamics and morphodynamics of a seasonally forced tidal inlet system

Hydrodynamics and morphodynamics of a seasonally forced tidal inlet system are investigated using numerical models. The ocean forcing including tidal and wave actions and sediment transport is simulated using Delft3D model. Fluvial processes in Delft3D are taken into account as results from SOBEK RURAL model. Analysis of the numerical simulation...