How different surrounding environments influence the characteristics of flash flood-mortality: The case of the 2017 extreme flood in Mandra, Greece

In November 2017, a high-intensity storm caused a catastrophic flash flood that devastated the city of Mandra, in Greece, and led to the tragic loss of 24 people. The storm caused flooding in the two main tributaries of the basin, creating two very similar hydrological responses with similar flood characteristics that hit two different environments: one within the city and one outside. This work examines the fatal incidents that occurred in relation to the characteristics of the surrounding environment, to investigate the role of the latter in flood mortality. Then, the analysis carried out for the 2017 flood is expanded to a broader database of flood deaths for Greece (1960-2018) for comparison. Results show that certain mortality characteristics differ substantially depending on the setting. Outdoor incidents are more abundant in nonurban environments, in which victims exhibit mostly an active or risk-taking behaviour against the imminent risk. Urban environments are characterised by a greater diversity of victim activities, higher percentages of indoor deaths, especially for older victims and more passive behaviours. Overall, the study presents evidence on how risk situations develop differently between urban and nonurban settings. Findings are relevant in shaping policy and education programs aiming to mitigate risk.