The formation and development of tidal channels and salt marshes are
controlled by complex interactions between hydrodynamics, sediment
transport, and vegetation dynamics. Tidal channels affect and, at the
same time, are affected by the growth of salt marshes fringing them. The
coupled evolution of these morphological units is thus a key ingredient
for simulating the typical behaviour of tidal environments. We developed
a mathematical model accounting for vegetation-induced flow resistance
and wetting-drying processes typical of tidal environments, to
investigate the eco-morphodynamic evolution of intertidal areas fringing
a main channel and of the tidal creeks cutting through them. Model
results indicate that vegetation promotes the development of channel
networks, leading to more complex channel structures and higher drainage
efficiency. Vegetation encroachment influences sediment deposition
patterns by trapping sediment in the seaward and middle intertidal
areas, while reducing the amount of sediment delivered to landward
areas. In the presence of sea level rise, this deficit of sediment
enhances the landward-decreasing trend of the intertidal platform and
leads to more isolated vegetation patches. Overall, sea level rise
restricts the extension of salt marshes and consequently reduces the
effect of vegetation on channel development.