Landscape evolution in tidal embayments: Modeling the interplay of erosion, sedimentation, and vegetation dynamics

We have set up a process-based eco-morphodynamic spatially-explicit model which conceptualizes the chief landforming processes driving the intertwined, long-term evolution of marsh platforms and tidal networks cutting through them. In fact, a holistic eco-geomorphological approach, incorporating the description of the strong feedbacks characterizing hydrodynamic and sediment transport processes on the one hand, and ecological dynamics on the other, is deemed to be essential to predict the future fate of such delicate systems. The model describes the ontogeny and long-term eco-morphological evolution of both tidal channel networks, driven by water-surface gradients and in dynamic equilibrium with local hydrodynamics, and the adjacent marsh areas, governed by sediment erosion and deposition and crucially affected by the presence of vegetation. Our modelling approach is tested against observations at one of our field sites in the Venice lagoon, also exploring the response of tidal morphologies to different scenarios of sediment supply, colonization by halophytes and changing sea level.