Cascading continental-scale floods across Europe in 1342-1343

Area of Science:

• Environmental Science
• Climate Science
• Historical Hydrology

Background:

• Europe has faced severe floods recently, but understanding historical extreme flood events is crucial for effective flood risk management.
• The Magdalena Flood of 1342 is often cited as the largest flood in Central Europe over the last millennium, yet its characteristics remain incompletely understood.

Purpose of the Study:

• To analyze historical flood data to better understand extreme flood characteristics and their implications for modern flood risk management.
• To investigate the 1342 Magdalena Flood and its context within a broader sequence of European flood events.

Main Methods:

• Analysis of a new documentary dataset detailing major flood events across Europe between late 1341 and 1343.
• Statistical analysis to determine return periods for identified extreme flood events.

Main Results:

• Sixteen major flood events occurred across Europe between late 1341 and 1343.
• Four of these floods (Magdalena, Bartholomew, Candlemas, and Jacob Floods) exhibited return periods of 500-1,000 years.
• 1342 stands out as the year with the most extreme floods in the past 700 years, with 1343 also ranking highly.

Conclusions:

• The 1342-1343 flood sequence was a broader phenomenon than previously recognized, with the Magdalena Flood being part of a larger pattern.
• This extreme flood period had significant socio-economic consequences, leading to a paradigm shift in European flood mitigation.
• A plausible cause for this flood sequence involves volcanic eruptions and Arctic sea ice retreat, highlighting the need for risk management strategies that consider clustered extreme events.