Investigation of the hydraulics in flooded housing estate

Climate change is currently taking place at the scale of our planet, leading to aviolent response from the environment, particularly with regard to the water cycle. One of the risk is already floods. As an example, in France, the average annual costof damages caused by floods (and insured under the Natural Disaster plan) amounts to 520 million euros. In metropolitan France, nearly 17 million people, about aquarter of the national population, are exposed to the risk of flooding by overflowaccording to the preliminary flood risk assessment carried out by the State in 2011.And with climate evolution, floods will become more frequent and more intense.Onechallenge during floods is to be able to access to people refugee over buildings.In order to investigate the hydraulic context generated by the grouped obstaclesrepresentative of a submerged housing estate, both an experimental and numericalstudy is being conducted.We experimentally study the flow in the presence of rows of macro-roughnesses representative of a slightly emerged and of a submerged housing estate, and this for situations representing both current and more intense floods. Measurements of the velocity field will provide information on currents distribution that might affect an evacuation process. In parallel a numerical study is also conducted with the opensource code Saturne. The numerical results are compared to experimental results and this preliminary stupy opens the way to a systematic investigation.