Hazard and vulnerability assessment of the damages produced in Barcelona in case of heavy storm events
M. VelascoA. Cabello
CETaqua Water Technology Center, Spain
B. Russo
CLABSA, Clavegueram de Barcelona SA, Spain
S. Djordjevic
University of Exeter, United Kingdom
Keywords:urban flood; vulnerability; depth-damage curves; resilience; CORFU
Urban areas are, due to the concentration of population and economic activities, one of the most sensitive regions to natural hazards. In the context of the EC 7th Framework ProgrammeProject CORFU(Collaborative Research on Flood Resilience in Urban Areas), resilience measures to cope with urban floods will be obtained, so the effects of drivers such as urban development, socio-economic trends and climate changes can be correctly dealt with. In order to assess the effectiveness of these measures, detailed vulnerability studies must be undertaken.
The different methodologies and models developed in the frame of the CORFU project will be applied in several case studies. This work presents the case study of the Raval district in Barcelona, where a new 1D-2D coupled model is used to obtain flood depth, and new stage-damage curves are developed.
The Raval district in Barcelona is located in a hollow area of the city which suffers from flooding problems when heavy storm events occur due to the excess of surface runoff and the poor capacity of the sewer system in some points of the city. They can produce significant hazard for the vehicular and pedestrian circulation, as well as economical damages in terms of goods and properties.
The general classification used for flood damage makes a first distinction between tangible and intangible damages, and a second one between direct and indirect damages. This work focuses on the direct tangible damages, which, in general, are estimated by the flood depth. Therefore, depth-damage curves have been adopted in multiple locations around the world as the most commonly used technique to assess flood vulnerability.
Depending on the information available and the goals of the assessment, there are several types of depth-damage curves. As in Barcelona there is a lack of historical damage data, and the building typology may be remarkably different from other regions previously studied, synthetic curves for the Raval district are being developed via a what-if analysis and using flood expertise acquired from past flood events in the area.
In this context, the obtention of water depth is crucial.Therefore, a new 2D/1D coupled model was created considering a 2D unstructured mesh for the flow propagation (adapted to the complex topography of the Raval district with narrow streets and courts) and main and secondary sewer networks for all the area. Moreover, a detailed Digital Elevation Model with a resolution of 1 m x 1 m and a precision of 15 cm in terms of ground level was used.