A finite element operational model for storm surge prediction in Venice

An accurate sea level prediction for the Venice Lagoon is of great importance to the historical city life and maintenance. In this paper an operational forecasting system of the sea level for the Venice Lagoon, based on a finite element numerical model, is presented. The model solves the shallow water equations on two different finite element grids representing the whole Mediterranean Sea and the Venice Lagoon. The system has been operational for 4 years, and it has been refined during this period through several improvements such as spatially variable wind enhancement coefficients and a post-processing procedure. Results show that the system is capable of achieving forecasts comparable to the statistical models that are presently used by the Venice municipality as their flooding warning system. In particular, for forecasting periods of 24 h and longer, the system performs better than the statistical models, whereas, on short time scales, i.e. 12 h or less, the statistical models still give the better forecast.