Flood risk: a complex probabilistic notion for citizens

Abstract

Floods and inundations are hazardous phenomena that make difficult decisions and communication towards citizens. The stochastic description of the river behaviour is difficult to explain, even sometimes for experts. At the end, people usually misunderstand the flood risk notions. Meanwhile, clear messages are necessary due to social and economic stakes. We try to identify some obstacles to objective flood risk perception and we propose some ways to build a representation of hazardous phenomena. We propose a formalisation through the image of coloured balls, function of floods probabilities.