DEUFI

Although urban floods were largely investigated, the flow exchanges between streets and buildings are not documented in the laboratory and seldom in the field. DEUFI project will fill this gap focusing on the hydraulic processes inside and outside one building and assessing how this knowledge can be useful to estimate and reduce damages and fatalities. The influence of the building openings along the streets is local but can diffuse to the general pattern of the flow propagation. Three scales are investigated for hydrodynamics purposes: the facade (including one or several openings such as doors, gates...), the block (built-up area surrounded by streets and including one or several buildings) and the district (including several streets and a lot of blocks). Information provided at one of these scales permits to estimate the level of risk and to take decisions about flood risk management at the individual or collective scales. At the façade scale, the calculation of the flow discharge through the openings is emphasized being the first step to evaluate the influence of these exchanges. At the block scale, the difference between flood hazard inside and outside the building is put forward particularly for damage assessment but the opening is also creating a disturbance in the flood hazard in the neighbouring streets, which may be important for safety evaluation. At the district scale, one investigates the flow propagation and its uncertainty because of the exchange between streets and buildings but also because of other factors; strategy for flood management should be elaborated from results at that scale. DEUFI project is structured in three work packages combining hydraulics, damage estimation and citizen approaches: laboratory experiments (WP1), field cases (WP2) and hydrodynamic models (WP3). WP1 gathers three sets of laboratory experiments using existing facilities and dealing with urban flow patterns at the facade, block and district scales respectively. WP2 focuses on two field cases in order to apply the developed methods on real configurations that differ by the geographical environment (origin of flooding, slopes …). WP2 groups the development of tools (software, data base …) at the field scale and the application of these tools on the two field cases in view of evaluating the relevancy for local stakeholders. WP3 develops hydrodynamic models that permit to pass from the laboratory scale to the field scale, validates them against WP1 results and compares their efficiency to produce results on the field cases useful for local stakeholders. DEUFI project will end-up with improved urban flood simulation methods capable of (i) estimating the flow intrusion within built-up areas, (ii) evaluating the spatial distribution of human exposure and material damage and (iii) proposing best-practice recommendations, in relation with the citizen perception and behaviour during short duration high floods. In order to reach these objectives, DEUFI project associates seven French partners dealing with hydraulics, economy, geography, sociology, hydrology, applied mathematics and computer sciences together with two foreign teams involved in related researches in their own countries. The diffusion of DEUFI results will benefit of the close coordination with local population and authorities as well as the participation of a consultancy company accustomed to building and disseminating research results.