The Role of An Accurate Estimation of Expected Damages in Flood Risk Management. Examples From the Basque Country (Spain) (PAP014837)

Código

PAP014837

Autores

David Ocio Moreno, Ignacio Villanueva Lacabrera, Christian Stocker, José María Sanz de Galdeano Equiza

Tema

Flood risk management in mega cities

Resumo

Dealing with a highly affected territory in terms of floods with a limited budget is always a difficult exercise of optimizing resources. In this scenario, flood protection policies must always be supported by an objective scheme in order to avoid any bias in allocating funds due to the subjective impact of recent episodes or to unjustified social demands. In accordance with the new European flood legislation, a comprehensive approach for flood risk management is presented here. It is organized in three different phases with the following aims: 1) to identify the areas that comprise the bulk of the potential damages within the studied region; 2) to elaborate flood hazard maps in the selected areas with state of the art hydrological and hydraulic techniques, as well as to elaborate flood risk maps including a detailed account of annual expected damages both in terms of affected population or likely casualties and of economic losses; and 3) to propose efficient structural measures starting with those that will reduce the overall flood risk quicker than others and to promote non-structural ones, such as early warning systems, reforestation, insurances, etc. The adopted methodology goes beyond the one proposed by the EU and is open to be discussed with the respective environment agencies. In the aforementioned procedure, an accurate calculation of flood damages is essential. Annual expected values must be close to reality if a proper cost-benefit analysis is to be conducted and its results regarded as valid. They must then include the impact of floods on buildings, goods, vehicles, infrastructures, etc. Once this is achieved, policy makers have a powerful tool to answer some critical questions, such as how to prioritize areas, which protection level is desirable or how to choose between protection alternatives. Some examples from the Basque Country (northern Spain) are provided.