Venice: sea-lagoon exchange in a modified tide regime.

Salinity and tide heights recorded for a month at P(0), a point in the northern section of the Venetian lagoon, are the basic experimental data used to construct a numerical model which describes the salinity variations at P(0) as a function of the tides measured at the Lido entrance. The time variation of the salinity pattern iss interpreted in terms of a lagoon system in which a freshwater source of constant intensity is in a quasi-steady equilibrium with a tide-modulated sink. The mean residence time of a contaminant in this simulated lagoon is predicted from the change in the salinity pattern due to a reduction in the entrance size.