The effects of wind‐generated currents on velocity asymmetry in tidal basins with varying geometries

2021 ◽  
Author(s):  
Peter J. De Ruiter ◽  
Julia C. Mullarney ◽  
Karin R. Bryan
Keyword(s):  
Tidal Basins

scholarly journals Future Response of the Wadden Sea Tidal Basins to Relative Sea-Level rise—An Aggregated Modelling Approach

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2198 ◽  
Author(s):  
Lodder ◽  
Wang ◽  
Elias ◽  
van der Spek ◽  
de Looff ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Wadden Sea ◽  
Dynamic Equilibrium ◽  
Tidal Inlet ◽  
Scale Model ◽  
Tidal Basin ◽  
Critical Limit ◽  
Tidal Basins ◽  
Rise Rate

Climate change, and especially the associated acceleration of sea-level rise, forms a serious threat to the Wadden Sea. The Wadden Sea contains the world’s largest coherent intertidal flat area and it is known that these flats can drown when the rate of sea-level rise exceeds a critical limit. As a result, the intertidal flats would then be permanently inundated, seriously affecting the ecological functioning of the system. The determination of this critical limit and the modelling of the transient process of how a tidal basin responds to accelerated sea-level rise is of critical importance. In this contribution we revisit the modelling of the response of the Wadden Sea tidal basins to sea-level rise using a basin scale morphological model (aggregated scale morphological interaction between tidal basin and adjacent coast, ASMITA). Analysis using this aggregated scale model shows that the critical rate of sea-level rise is not merely influenced by the morphological equilibrium and the morphological time scale, but also depends on the grain size distribution of sediment in the tidal inlet system. As sea-level rises, there is a lag in the morphological response, which means that the basin will be deeper than the systems morphological equilibrium. However, so long as the rate of sea-level rise is constant and below a critical limit, this offset becomes constant and a dynamic equilibrium is established. This equilibrium deviation as well as the time needed to achieve the dynamic equilibrium increase non-linearly with increasing rates of sea-level rise. As a result, the response of a tidal basin to relatively fast sea-level rise is similar, no matter if the sea-level rise rate is just below, equal or above the critical limit. A tidal basin will experience a long process of ‘drowning’ when sea-level rise rate exceeds about 80% of the critical limit. The insights from the present study can be used to improve morphodynamic modelling of tidal basin response to accelerating sea-level rise and are useful for sustainable management of tidal inlet systems.

scholarly journals Influence of geometrical variations on morphodynamic equilibria in short tidal basins

2018 ◽  
Vol 69 (2) ◽  
pp. 221-238
Author(s):  
Corine Meerman ◽  
Vivi Rottschäfer ◽  
Henk Schuttelaars
Keyword(s):  
Tidal Basins

scholarly journals Net sediment transport in tidal basins: quantifying the tidal barotropic mechanisms in a unified framework

2017 ◽  
Vol 67 (11) ◽  
pp. 1385-1406 ◽  
Author(s):  
Vincenzo Marco Gatto ◽  
Bram Christiaan van Prooijen ◽  
Zheng Bing Wang
Keyword(s):  
Sediment Transport ◽  
Unified Framework ◽  
Tidal Basins

scholarly journals Turning the tide: experimental creation of tidal channel networks and ebb deltas

2012 ◽  
Vol 91 (3) ◽  
pp. 311-323 ◽  
Author(s):  
M.G. Kleinhans ◽  
M. van der Vegt ◽  
R. Terwisscha van Scheltinga ◽  
A.W. Baar ◽  
H. Markies
Keyword(s):  
Initial Conditions ◽  
Scale Effects ◽  
Morphological Evolution ◽  
Rate Of Change ◽  
Tidal Basin ◽  
Tidal Channel ◽  
Channel Networks ◽  
Initial Water ◽  
Tidal Period ◽  
Tidal Basins

AbstractTidal channel networks, estuaries and ebb deltas are usually formed over a period longer than observations cover. Much is known about their characteristics and formation from linear stability analyses, numerical modelling and field observations. However, experiments are rare whilst these can provide data-rich descriptions of morphological evolution in fully controlled boundary and initial conditions. Our objective is to ascertain whether tidal basins can be formed in experiments, what the possible scale effects are, and whether morphological equilibrium of such systems exists.We experimentally created tidal basins with simple channel networks and ebb deltas in a 1.2 by 1.2 m square basin with either a fixed or self-formed tidal inlet and initially flat sediment bed in the tidal basin raised above the bed of the sea. Rather than create tides by varying water level, we tilted the entire basin over the diagonal. The advantage of this novel method is that the bed surface slopes in downstream direction both during flood and ebb phases, resulting in significant transport and morphological change in the flood phase as well as the ebb phase. This overcomes the major problem of earlier experiments which were entirely ebb-dominated, and reduces the experiment time by an order of magnitude.Ebb deltas formed in sand were entirely bedload dominated whereas the lightweight plastic sediment was intermittently suspended. Channels bifurcated during channel deepening and backward erosion to form a network of up to four orders. For initially dry tidal plains, the tidal prism increased as more sediment eroded from basin to ebb delta, so that evolution accelerated initially. The rate of change, the size of the channels and the final length of channels and delta were very sensitive to the tidal amplitude, tidal period and initial water depth in the basin. Most experiments with sand terminated with all sediment below the threshold for motion, whilst lightweight sediment remained mobile in the inlet region and firstorder channels, suggesting that sustained morphodynamics are feasible in experiments. We discuss how this novel experimental setup can be extended to produce tidal deltas, estuaries and other tidal systems and study their dynamics as a function of their forcing.

Modeling wind waves and tidal flows in shallow micro-tidal basins

2011 ◽  
Vol 92 (2) ◽  
pp. 263-276 ◽  
Author(s):  
L. Carniello ◽  
A. D’Alpaos ◽  
A. Defina
Keyword(s):  
Wind Waves ◽  
Tidal Basins ◽  
Tidal Flows

scholarly journals Morphodynamics of river-influenced back-barrier tidal basins: The role of landscape and hydrodynamic settings

2014 ◽  
Vol 50 (12) ◽  
pp. 9514-9535 ◽  
Author(s):  
Z. Zhou ◽  
G. Coco ◽  
M. Jiménez ◽  
M. Olabarrieta ◽  
M. van der Wegen ◽  
...  
Keyword(s):  
Tidal Basins
Sign in / Sign up

Export Citation Format

Share Document