Large floods in Europe, 1985-2009

The paper looks at two metrics of flood events: flood severity (related to flood frequency) and flood magnitude (related to flood severity, as above, but also to flood duration and affected area). A time series of flood information, over 25 years, collected by the Dartmouth Flood Observatory, is used to describe the spatio-temporal variability of large floods in Europe. Direct factors responsible for changes in flood severity and magnitude over time may be related to both climate and ground surface changes. Indirect links between flood severity/magnitude and socio-economic indices occur via flood risk reduction activities, land-use change and land-cover change. The present analysis shows an increasing trend during the 25-year period in the number of reported floods exceeding severity and magnitude thresholds.