An idealized study of the circulation in the Orbetello lagoon, Italy

An idealized study of the circulation in the Orbetello lagoon has been carried out with a shallow water finite element model, developed at the ISMAR-CNR in Venice. The influence of openings on the dam that divides the Orbetello lagoon in two parts has been studied. Four different grids, corresponding to different dam scenarios with increasing openings of the dam, from the actual situation to the complete elimination of the dam, have been realized for the simulations. The effect of different forcings such as tide, water pumps and wind have been taken into account to characterize the general pattern of the circulation in the Orbetello lagoon, with particular attention to the area close to the dam. Results show that the water movement is mainly induced by the wind action, whereas the tide has a quite negligible effect in the Orbetello lagoon. It is shown that a partial opening of the dam might be a good compromise between a complete removal of the dam and the actual situation that blocks the water exchange. The study shows that numerical models could offer a useful tool for helping in the management and safeguarding of the water resources, especially in coastal ecosystems.