A Framework to Assess Urban Floods Resilience

Urban flooding is still often treated as a straight consequence of excess rainfall, without considering the watershed as an interdependent system connected with the development of its territory. The traditional approach implies continuous corrective interventions, usually of local character and resulting from post-events responses. This process requires increasingly large investments to implement structures capable to accommodate the runoff generated by urbanization. These efforts have not prevented floods from continuing to cause major damage worldwide, indicating the need for a change in storm water management strategy, shifting from a simple cost-benefit analysis to a risk management approach, with residual risk internalization, regarding inherent uncertainties, such as climate change and fast and uncontrolled urban growth. This paper proposes a multi-criteria index, the Urban Flood Resilience index-UFRI, to quantitatively measure resilience to floods, supported by a hydrodynamic mathematical model and socio-economic indicators, resulting in spatialized maps. A case study for an urban watershed in Rio de Janeiro is used to demonstrate UFRI potential.