  Results of an application of a dispersive wave hydro-sediment-morphodynamic
model in the western circulation cell of the Ria Formosa lagoon located in the
Algarve region of the southern Portugal are presented. This area of interest
has a couple of features that complicate the application of the dispersive wave
model: (1) the area has a complex irregular geometry with a number of barrier
islands that separate the lagoon from the Atlantic Ocean, artificial and
naturally occurring tidal inlets, and a number of curling channels inside the
lagoon that interconnect the inlets and serve as waterways between the lagoon
settlements; (2) the tidal range in the area can reach up to 3.5 m; therefore,
the terrain inside the lagoon is characterized by vast salt marshes and tidal
flats, and the wetting-drying process is a key component of any hydrodynamic
simulation in this area. A model representation of the area has been developed
by generating an unstructured finite element mesh of the circulation cell, and
collecting data on parameters that characterize the tidal waves in the area,
and bottom friction and sediment transport models used in the simulations. The
results of the simulations indicate that the dispersive wave model can be
applied in coastal areas with nontrivial underlying physical processes, and
complex irregular geometries. Moreover, the dispersive term of the model is
capable of capturing additional flow characteristics that are otherwise not
present in hydrodynamic simulations that involve the nonlinear shallow water
equations; and these additional flow features can, in their turn, affect the
resulting sediment transport and bed morphodynamic process simulations.

Geophysics;Fluid Dynamics