Analyzing the civil engineering infrastructures to prioritize urban flood resilient actions

The behavior of the civil engineering infrastructures, and their interactions during a flood event, will have consequences on the flood risk level in the built environment. By civil engineering we include on one hand the flood defenses, able to increase the flood risk in case of failures, on the other hand the urban technical networks able to spread the flood risk in cities. From history, most of cities in the world have been built close to coast lines or to river to beneficiate this means of communication and trade. Step by step, to avoid being flooded, defenses like levees have been built. The capacity of the levees to retain the floods depends on their conditions, their performance level and the capacity of the authorities to well maintain these infrastructures. Then, in case of levee break, cities will be flooded. The urban technical networks, due to the way they have been designed, their conditions and their locations in the city, will play a major role in the diffusion of the flood extent. Also, the flood risk will have consequences in some not flooded neighborhoods due to networks collapses. The methods we are using to determine the performance level of flood defenses and the level or resilience of the urban networks with three specific capacities are described. Then, an integrated spatial decision support system is presented.