Drivers of cross-shore chenier dynamics off a drowning coastal plain

Drivers of cross-shore chenier dynamics off a drowning coastal plain

Tas, S.A.J. (TU Delft Environmental Fluid Mechanics)
van Maren, D.S. (TU Delft Environmental Fluid Mechanics; East China Normal University; Deltares)
Helmi, Muhammad (Universitas Diponegoro)
Reniers, A.J.H.M. (TU Delft Environmental Fluid Mechanics)

2022

A chenier is a beach ridge, consisting of sand and/or shells, overlying a muddy substrate. In this paper, we explore the cross-shore dynamics of cheniers in their ‘active’ phase, i.e. the phase between their formation and their landing on the shore and can no longer be reached by daily wave and tidal influences. While cheniers described in literature are known to only migrate onshore until they reach a stable position with their crest level above tidal influences, observations in Demak suggest the existence of an alternative stable state, highly dynamic on the short term, but stable on the longer term. To explore this alternative stable state, we developed an idealised chenier model to investigate cross-shore chenier dynamics under daily wave and tidal influences. The model is able to predict both onshore and offshore migration; onshore migration is mainly driven by wave action, while offshore migration is induced by a tidal phase lag, or the effect of the storm season. For certain combinations of waves, tide (incl. phase lag) and a storm season effect, the model predicts a dynamically stable chenier. In absence of a phase lag and storm season effect, the model yields a ‘classic’ stable chenier that welds onto the shoreline by onshore migration.

Cheniers
Modelling
Morphodynamics
Tide
Waves

http://resolver.tudelft.nl/uuid:99e88b1c-75e8-4ed4-8207-75b33cea4b96

https://doi.org/10.1016/j.margeo.2022.106753

0025-3227

Marine Geology, 445

Institutional Repository

journal article

© 2022 S.A.J. Tas, D.S. van Maren, Muhammad Helmi, A.J.H.M. Reniers