Modeling the Venice Lagoon residence time

In this work the water residence time of the Venice Lagoon has been computed using a 2D hydrodynamic model. The model is based on the finite element method. It solves the shallow water equations on a spatial domain that represents the whole Adriatic Sea and the Venice Lagoon. The residence time has been defined through the remnant function of a passive tracer released inside the lagoon. The renewal capacity of the Venice Lagoon has been investigated when forced by the astronomic tide and by the two main local winds, bora and scirocco. The importance of the return flow from the Adriatic into the lagoon is shown. This influence has been quantified by the definition of the return flow factor that has been computed for each scenario.