Morphological evolution and time-varying bedrock control of main channel at a mixed energy tidal inlet: Maumusson Inlet, France

Bertin, Xavier; Chaumillon, Éric; Weber, Nicolas; Tesson, Michel

doi:10.1016/s0025-3227(03)00353-0

Cited by 42 publications

(35 citation statements)

References 15 publications

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“…The work of Bertin et al (2004) furthermore illustrates the potential for complex geomorphic behaviour due to structural controls that are temporally as well as spatially variable. This idea is not new, and various authors have demonstrated the importance of temporal and spatial variability in geomorphic sensitivity and processresponse (e.g.…”

Section: Introductionmentioning

confidence: 91%

“…This may impede progressive adjustment toward a new alluvial equilibrium and may stimulate an extensive suite of complex response (Schumm, 1973). In Loughros More, bedrock control has been 'switched on' through dune erosion, whereas Bertin et al (2004) provide an example of bedrock control being 'switched off' as result of infilling within the Maumusson Inlet. In both situations, there are direct morphodynamic consequences, generally in the shift in erosional and depositional focus.…”

Section: Variability In Structural Controlmentioning

confidence: 99%

“…The transgressive nature of many contemporary estuaries shows a spatial continuity to antecedent drainage networks (e.g. Fitzgerald et al, 2002;Hobbs, 2004;Bertin et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

“…Such a structural imprint is usually considered to exert a static control, but there is clear evidence that bedrock features can play a far more dynamic role in system behaviour. In the Maumusson Inlet (Atlantic coast of France), Bertin et al (2004) identified two distinct stages of structural-control on inlet dynamics, whereby a bedrock-incised palaeovalley acts in the first stage to constrain channel position, hence fulfilling a function as littoral-obstacle. Subsequent estuary and inlet infilling, and a consequent reduction in tidal prism promotes a second stage where the palaeo-valley imparts no control on channel position, thereby facilitating a change to a littoralbypassing inlet-function.…”

Section: Introductionmentioning

confidence: 99%

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Contrasting geomorphic response to structural control: The Loughros estuaries, northwest Ireland

Burningham¹

2008

Geomorphology

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Section: Introductionmentioning

confidence: 91%

Section: Variability In Structural Controlmentioning

confidence: 99%

“…The transgressive nature of many contemporary estuaries shows a spatial continuity to antecedent drainage networks (e.g. Fitzgerald et al, 2002;Hobbs, 2004;Bertin et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Contrasting geomorphic response to structural control: The Loughros estuaries, northwest Ireland

Burningham¹

2008

Geomorphology

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“…Bertin et al, 2004;Stive and Wang, 2003;Vila-Concejo et al, 2003;Zhang et al, 1995;Zhang, 1995b). The evolution of of the entrance channels is related with the general characteristics of the tidal inlet system.…”

Section: Introductionmentioning

confidence: 99%

Process-based modeling of morphodynamics of a tidal inlet system

2010

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The morphodynamic evolution of an idealized inlet system is investigated using a 2-D depthaveraged process-based model, incorporating the hydrodynamic equations, Englund-Hansen's sediment transport formula and the mass conservation equation. The model has a fixed geometry, impermeable boundaries and uniform sediment grain size, and driven by shore-parallel tidal elevations. The results show that the model reproduces major elements of the inlet system, i.e., flood and ebb tidal deltas, inlet channel. Equilibrium is reached after several years when the residual transport gradually decreases and eventually diminishes. At equilibrium, the flow field characteristics and morphological patterns agree with the schematized models proposed by O'Brien (1969) and Hayes (1980). The modeled minimum cross-sectional entrance area of the tidal inlet system is comparable with that calculated with the statistical P-A relationship for tidal inlets along the East China Sea coast. The morphological evolution of the inlet system is controlled by a negative feedback between hydrodynamics, sediment transport and bathymetric changes. The evolution rates decrease exponentially with time, i.e., the system develops rapidly at an early stage while it slows down at later stages. Temporal changes in hydrodynamics occur in the system; for example, the flood velocity decreases while its duration increases, which weakens the flood domination patterns. The formation of the multi-channel system in the tidal basin can be divided into two stages; at the first stage the flood delta is formed and the water depth is reduced, and at the second stage the flood is dissected by a number of tidal channels in which the water depth increases in response to tidal scour.

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Depth‐limiting resistant layers restrict dimensions and positions of estuarine channels and bars

Pierik

Leuven

Busschers³

et al. 2022

The Depositional Record

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Estuaries comprise channels vital for economic activity and bars as valuable habitats. They are increasingly under human-induced pressures (e.g. sea-level rise and dredging), resulting in morphological changes that affect navigability, flood safety and ecology. Antecedent geology may strongly steer how estuary channels will adapt to these pressures, but is surprisingly absent in most models. Here geological data and a unique bathymetry dataset covering 200 years from the Ems-Dollard estuary (Netherlands/Germany) were used to demonstrate how local resistant layers force the position and dimensions of confluences and bars on the scale of an entire estuary. These layers limit channel depth and consequently cause widening, resulting in mid-channel bar formation and increased channel curvature. This could lead to unexpected estuary widening and may cause land loss in densely populated areas. With increasing channel volume (as may happen again under future sea-level rise), resistant layers in the estuary's substrate become more exposed, which enhances their effects. Many systems around the world contain shallow resistant layers that potentially constrain estuary channel dimensions and steer bank erosion. This highlights that resistant layer effects are important to consider as part of mixed depositional processes in coastal environments. It is therefore necessary to globally account for the effects of inherited resistant layers in the possible response of estuaries to sea-level rise and increased tidal penetration.

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Morphological evolution and time-varying bedrock control of main channel at a mixed energy tidal inlet: Maumusson Inlet, France

Cited by 42 publications

References 15 publications

Contrasting geomorphic response to structural control: The Loughros estuaries, northwest Ireland

Contrasting geomorphic response to structural control: The Loughros estuaries, northwest Ireland

Process-based modeling of morphodynamics of a tidal inlet system

Depth‐limiting resistant layers restrict dimensions and positions of estuarine channels and bars

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