The city of Genoa is internationally known its the recurrent floods, mainly related to the Bisagno River._x000D_
The high risk is linked to meteo-hydrological hazard and to the urbanisation in hazardous areas and consequently to the high exposure of risk elements._x000D_
The present research concerns the hydrographic network that characterises the historical center of Genoa, i.e. the natural amphitheatre bordering the Polcevera valley to the W and the Bisagno valley to the E._x000D_
In this area of just 8.5 km2 there are eight catchments ranging from 0.49 km2 to 2.36 km2 in size: from W to E we recognise the basins of the San Bartolomeo, San Lazzaro, San Teodoro, Lagaccio, Sant’Ugo, Carbonara, Sant’Anna and Torbido streams._x000D_
These watercourses have been subject to anthropic modifications since the Middle Ages, sometimes with significant diversions, rectifications and channelling; today the watercourse network appears almost entirely artificial, flowing under the streets and buildings of the historic centre. The name of some alleys recalls their presence, which is otherwise not perceptible. Only the upper basin of the Lagaccio and San Lazzaro streams still have a watercourse with a natural riverbed, although the area is still significantly urbanised._x000D_
The construction of these culverts over time and the modifications they have undergone over the following centuries up to very recent times due to progressive urbanisation have led to a reduction in the hydraulic cross-section, which can lead to a possible flow of water under pressure and the consequent flooding hazard._x000D_
Therefore a better geographic knowledge of these culverted streams in Genoa historical city is crucial for hazard and risk assessments and for the planning of related hydraulic risk reduction activities._x000D_

F. Faccini1, P. Piana1, S. Saj2, M. Terrone3
1 Università di Genova, Italia; 2 Centro Studi Sotterranei, Genova, Italia; 3 Comune di Genova, Sistemi Informativi Geografici

 
ID Abstract: 120