Diagnostic modeling of the shoreline variation along the Jiangsu Coast, China

Diagnostic modeling of the shoreline variation along the Jiangsu Coast, China

Kuai, Y. (TU Delft Coastal Engineering)
Aarninkhof, S.G.J. (TU Delft Hydraulic Engineering)
Wang, Zhengbing (TU Delft Coastal Engineering; Deltares)

Hydraulic Engineering

2023

Intertidal flats are of great socio-economic and ecological importance in defending the coastal cities from flooding, providing resources for land reclamations and habits for wildlife. On the intertidal flats, milder profiles are usually featured with finer sediment. However, we find the opposite relationship between the alongshore variation in intertidal slope and sediment grain size on the intertidal flat along the Jiangsu Coast. With a conceptual figure of the hydrodynamics and shoreline evolution on this coast, we hypothesize that the unexpected pattern is caused by the alongshore gradient in hydrodynamic forcing. In order to test our hypothesis, we carry out a series of numerical model simulations in a highly schematized manner to investigate the real mechanism behind this unexpected pattern. Through the analysis, we find that only the southwards coarsening pattern is inconsistent with the shoreline evolution pattern. This inconsistency is not induced by alongshore hydrodynamic gradient, and can only be explained by different sediment provenances. We also find that the alongshore shoreline evolution pattern is not only determined by the alongshore gradient in hydrodynamic forcing, but also influenced by the alongshore variation in bed composition. In the erosion/sedimentation transition zone, the bed composition factor plays the major role.

Intertidal flat
Beach slope
Sediment grain-size
Bed composition
Jiangsu Coast

http://resolver.tudelft.nl/uuid:1066745a-5361-4246-874b-defe7921c8f7

https://doi.org/10.1016/j.geomorph.2023.108581

0169-555X

Geomorphology, 425

Institutional Repository

journal article

© 2023 Y. Kuai, S.G.J. Aarninkhof, Zhengbing Wang