A database on flash flood events in Campania, southern Italy, with an evaluation of their spatial and temporal distribution

Abstract. This study presents an historical database of flash flood events in the Campania region of southern Italy. The study focuses on small catchments characterized by intermittent flow, generally occurring during and after heavy rainstorms, which can be hydrologically defined as small Mediterranean catchments. As the outlet zones of these catchments (consisting mainly of alluvial fans or fan deltas) are highly urbanized in Campania, the population living in the delivery areas is exposed to high risk. Detailed scrutiny and critical analysis of the existing literature, and of the data inventory available, allowed us to build a robust database consisting of about 500 events from 1540 to 2015, which is continuously updated. Since this study is the first step of a longer project to perform a hazard analysis, information about time and site of occurrence is known for all events. As for the hazard analysis envisaged, collecting information about past events could provide information on future events, in terms of damage and also spatial and temporal occurrence. After introducing the issue of flash floods in Italy we then describe the geological and geomorphological settings of the study area. The database is then presented, illustrating the methodology used in collecting information and its general structure. The collected data are then discussed and the statistical data analysis presented.