From climate predictions to flood risk assessment for a portfolio of structures

Assessment and prediction of the adverse effects of the climate-related events, quantification of the vulnerability of the affected areas and risk assessment are important steps in an integrated climate change adaptation strategic decision-making procedure. Thiswork presents a probabilistic performance-based procedure for flood risk assessment for the structures in a portfolio of spatially-distributed structures in a detailed microscale. This methodology has its starting point in the down-scaling of global climate projections for a prescribed climate scenario and historical data as far as it regards the rainfall intensity, duration and frequency. The risk is expressed in terms of the annual rate (and probability) of exceeding a structural limit state, expected replacement cost and expected number of people endangered by the flooding (hypothesis of no evacuation). This procedure is described through an application for Suna, a subward of Magomeni in Dar es Salaam City (Tanzania), located in the Msimbazi river basin, having a high concentration of informal settlements.