Flash Flood Events and Urban Development in Genoa (Italy): Lost in Translation

Coastal locations in the Mediterranean area experienced several geo-hydrological events from the beginning of the 3rd Millennium. Among the most flooded areas featuring the Ligurian coastal environment, Genoa is sorrowfully at international level, for the flash flood characteristics and consequent damage: the last event of 4 November 2011, once again, caused the loss of human lives. Genoa, in fact, can be considered an interesting case study for geo-hydrological risks: it can be said that to a general trend of increasing hazard, due to global and particular climate changes of the Mediterranean area, corresponds an increase of the vulnerability due to the urban growth on the flood plains. In this paper are analyzed the unusual meteorological characteristics of the Gulf of Genoa, the changes in the rate of daily precipitation using the recorded data at the station of Genoa, in use since 1833. The most significant periods of the land urban development are also briefly described. They have determined important changes of the territory, modifying the water balance of the basins in a considerable way.