Print Email Facebook Twitter Modeling Decadal Salt Marsh Development Title Modeling Decadal Salt Marsh Development: Variability of the Salt Marsh Edge Under Influence of Waves and Sediment Availability Author Willemsen, P. W.J.M. (University of Twente; Universiteit Utrecht; Deltares) Smits, B. P. (Deltares) Borsje, B. W. (University of Twente) Herman, P.M.J. (TU Delft Environmental Fluid Mechanics; Deltares) Dijkstra, J. T. (Deltares) Bouma, T. J. (Universiteit Utrecht) Hulscher, S. J.M.H. (University of Twente) Date 2022 Abstract Salt marshes can contribute to coastal protection, but the magnitude of the protection depends on the width of the marsh. The cross-shore width of the marsh is to a large extent determined by the delicate balance between seaward expansion and landward retreat. The influence of the magnitude of daily occurring mild weather conditions and sediment availability on the variability of salt marsh width has not been systematically assessed. This paper investigates how the magnitude of homogeneous hydrodynamic forcing, combined with sediment availability, affects the biophysical development, and more specifically retreat and expansion of salt marshes. The dynamic extent of the salt marsh is assessed by modeling online-coupled hydrodynamics, morphodynamics and vegetation growth using the numerical Delft3D-Flexible Mesh model, and a vegetation growth module. Simulated patterns around the salt marsh edge resembled field observations, as well as the simulated temporal variability of the lateral position of the salt marsh edge. In the model, the salt marsh extended seaward at low wave forcing (0.00 m; 0.05 m), and retreated landward at higher wave forcing (0.10 m; 0.15 m). With increasing physical stress, the salt marsh edge was found at lower elevations, indicating an unhealthy system with a retreating marsh edge due to vegetation mortality, whereas decreasing physical stresses result in a higher salt marsh edge, enabling expansion. This balance suggests the importance of response time of vegetation to physical stress. Yet, the salt marsh forced with higher waves was able to switch from a retreating extent retrogradational to an expansional behavior as sediment supply increased. Subject biogeomorphological dynamicsbuilding with natureDelft3D-FMnature based flood defensesalt marshvegetation development To reference this document use: http://resolver.tudelft.nl/uuid:1ed92190-5c49-4100-be50-9d7610a1a7b8 DOI https://doi.org/10.1029/2020WR028962 ISSN 0043-1397 Source Water Resources Research, 58 (1) Part of collection Institutional Repository Document type journal article Rights © 2022 P. W.J.M. Willemsen, B. P. Smits, B. W. Borsje, P.M.J. Herman, J. T. Dijkstra, T. J. Bouma, S. J.M.H. Hulscher Files PDF Water_Resources_Research_ ... h_Edge.pdf 3.22 MB Close viewer /islandora/object/uuid:1ed92190-5c49-4100-be50-9d7610a1a7b8/datastream/OBJ/view