Venice flood protection implementation of an operational flood warning system  <B>Venice flood protection implementation of an operational flood warning system</B><P>J.R. Vieira, J. Fons and H. KofoedHansen</B><I><P> Danish Hydraulic Institute, Hoersholm, Denmark</I><P> Abstract<P> The risk of flooding in Venice has increased strongly since the beginning of the century. To reduce the damage to the city and the negative impact on the activities in the lagoon, a flood warning system composed of statistical and hydrodynamic models has been developed for the Ministry of Public Works, Magistrato Alle Acque, under the direction of Consorzio Venezia Nuova (CVN). In the future this warning system will also be fundamental during the construction and for the efficient operation of storm surge barriers covering the three existing inlets of the lagoon.<P> Following a management strategy for the integration and coordination of the project, the implementation of a first phase of operation was initiated at the beginning of 1995. In this initial phase only statistical models are being used operationally. These models, which are based on a multiple regression technique, extend the forecasting range, with respect to the previous system, from 3 to 24 hours. The meteorological forecasts used till now are transmitted online every 12 hours from the Danish Meteorological Institute to Centro Previsioni e Segnalazioni Maree del Commune di Venezia where the warning system is run.<P> For longer forecasts (>24 hours) a complex of hydrodynamic models, composed of a general model of the Adriatic Sea (6 km grid), a regional North Adriatic model (700 m grid) and two local models of the Venice Gulf and Lagoon (300 and 75 m grid), have also been developed. At the time of writing this modelling complex constitutes a prototype system, which is expected to be put into operation in 1996 following a new development phase. One of the problems to address will be the specification of long term water level variations at the entrance of the Adriatic due to external meteorological effects.<P> The operational system is fully automatized and provided with an adhoc interface for the operator's expeditious intervention when necessary.<P>