Hydrodynamic and salinity modeling of the Venice channel network with coupled 1-D–2-D mathematical models

An existing shallow water finite element model of the Venice Lagoon (SHYFEM) has been used to simulate currents and the tidal elevations around the city of Venice. The model is also capable of simulating the salinity field (as any other conservative scalar property) in the lagoon. The model uses a semi-implicit time stepping scheme allowing for long time steps without stability constraints. The computed elevation data are then used to drive the actual model of the channel network of Venice, the 1-D link node model DYNHYD of the EPA-WASP model. The water levels are imposed on the outer ends of the channel network. With this information the DYNHYD model computers water levels and current velocities inside the channel network. Therefore, information flow is only one way from the lagoon to the channel system. Results show an excellent agreement of the hydrodynamic parameters with the data obtained by field measurements carried out during the years 1991–1992 and 1998. Water levels and current velocities are reproduced with good agreement. Also the salinity can be modeled with sufficient detail.