The IMPACT European research project on Flood Propagation in urban areas: Experimental and numerical modelling of the influence of buildings on the flow

Abstract

The IMPACT European project addresses the assessment and reduction of risks from extreme flooding caused by natural events as well as by the failure of dams and flood defence structures. The project covers five main research themes, one of these consists in the work package “Flood Propagation”, which particularly focuses on floods in urban areas. The present paper presents some results of the IMPACT project in that field In a first stage, experiments are conducted in two different scale models. The first series of experiments consists in an idealised dam-break flow against a single building while the second series represents a heavy flood in a simplified urban district with a series of buildings Parallel to these experiments, numerical strategies are developed for the simulation of floods in urban areas, such as exact representation of each single building, inclusion of the buildings in the topographic data or definition of urban areas as regions with a higher friction coefficient. Those strategies are then tested against the experiments A variety of numerical strategies were developed by some members of the IMPACT research team. Results of those numerical simulations are then compared to the experiments in order to assess the validity of each proposed strategy. From there, conclusions are drawn with the aim of providing some guidance to future modellers to optimise the flow modelling in urban areas.