Hydrodynamic modeling in the channel network of Venice

A combined framework of hydrodynamic models is presented that describes the water dynamics in the channel network of the city of Venice. The application of these hydrodynamic models is part of a larger project carried out by UNESCO that has the aim of describing the water quality of the channels in Venice. An existing 2-dimensional finite element model simulates the hydrodynamic features in the Venice Lagoon. The simulated data is then used as the boundary condition for the 1-dimensional hydrodynamic model of the inner channels of Venice. Inside the channel system the water elevation and the current velocities are computed. The simulated variables are calibrated and compared with data from field measurements that UNESCO has carried out during the years 1990-92 and during 1998. It was possible to use a constant friction parameter for all the channels in the network. Simulated water elevation shows an excellent agreement with the measured data, and also current velocities are generally reproduced quite faithfully. Some low-energy channels show major errors in the reproduction of the velocity speed. It is believed that changing bathymetry (silting-up of the channels) could be a cause of this phenomenon. The hydrodynamic data will eventually be used in the second part of the project where the water quality of the channel network will be investigated. For this purpose the hydrodynamic parameters simulated will be used by the water quality model as a boundary and initial condition in order to simulate the biological and chemical variables and to describe the ecological dynamics