Urban wind design for Bonifacio’s citadel – By Urbalterre at the 9th International Conference on Urban Climate

Bonifacio Urbalterre WindTest

The citadel of Bonifacio is located at the extreme south of Corsica. That small maritime city was built on a peninsula, up to 50 meters above the sea, to protect the commercial route crossing by the strait of Bonifacio between Corsica and Sardegna. By 1996, the army abandoned the city, leaving 30.000 square meters of land and buildings to transform.

The project deals with the needs of the old city, transportation concerns, economical and tourism development, and environmental concern. Around 2 millions tourists visit Bonifacio each summer, and the city would like to welcome visitors all seasons long. The project comprises a museum, a new luxurious hotel, a big parking and some public facilities.

But, even for summer journeys, if you stay in Bonifacio you will run the risk of strong wind events. Indeed, Bonifacio is the windiest city of Mediterranean area, and one of the windiest in the world. A strong wind is blowing up to 155 days a year, and up to 100 km/h for 20 days amongst it.

To ensure pedestrian safety and comfort for the new streets and public spaces of the citadel, we developed an urban design process, combining Computational Fluid Dynamics (CFD) models and wind tunnel testing with PIV measurements. As a result, the design for the new district organises protected areas with a concept of protection belts. The concept uses new buildings and old ones, gardens with progressive heights of trees, to reduce wind speed and turbulent flow.

In the past, the citadel ensured protection for the army to control the strait. Today, the citadel is open and welcomes tourists to visit a place now dedicated to the environmental protection of the strait.


Dominique Dias1, Sylvain Aguinaga2, Marc Dufresne2

1Urbalterre, France; 2CSTB, France.