When Driving to Work Becomes Dangerous

Abstract: Although flash floods affect relatively small areas compared to other types of floods, they lead to a significant number of victims. Based on EMDAT (“International Disaster Database”) data, Jonkman showed that the mortality rate associated with flash floods is significantly higher than that of slow floods (3.6% vs. 0.5%). The various studies on the human impacts of flash floods have shown a high prevalence of car-related accidents in Europe (40%–50%) and the USA (more than 60%). Based on a detailed analysis of the circumstances of the deaths, we also found a link between the type of circumstance (e.g. outdoors or indoors), the victims’ profile, the watersheds response times, and the accident times. Thus, unlike deaths at home, which mainly affect the elderly during the reaction of large watersheds (> 1,000 km2) reacting in several hours, travel-related deaths mainly affect men in their prime, surprised by the very rapid rise of rivers draining small areas (a few dozen km2). This observation raises questions about the respective influence of exposure factors related to daily mobility practices and behavioral factors in response to the emergency caused by flood situations.