Spatial cost benefit analysis in flood risk management: Evidence from a case study in Italy

The number of natural catastrophes is increasing worldwide: among these, flood is one of the worst hazards causing thousands of losses of life and damages to property. Flood risk mitigation was traditionally carried out by reducing the hazard through the construction of structural hydraulic defenses. Nowadays, the approach to flood risk mitigation is conceived as combination of structural and non-structural defenses, as recommended in UN/ISDR, (2005) and in the EU Flood Directive (60/2007): in the specific, the EU directive requires the ex-ante evaluation of costs and benefits from mitigation measures in risk management plans. In this light, the paper proposes the application of a Cost-Benefit Analysis (CBA) to a case study of the city of Olbia in Sardinia Region, example of Historic Urban Landscape (HUL) in Italy, in order to support the public administration in the choice of the most sustainable plan, reducing social and environmental risk and, at the same time, ensuring its feasibility from a financial and economic perspective.