Holocene and Late Pleistocene Flood Events in Central Europe Reconstructed from Eifel Maar Lake Sediments

Severe floods such as in the Ahr valley in July 2021 are one of the leading causes of fatalities from natural disaster. Riverine and lacustrine floods are caused by a sudden flux of water masses from heavy rainfall or snowmelts. These surface water runoff events significantly enhance erosion of detrital material in the catchment, which is then deposited in natural sinks such as lakes. We reconstructed flood phases from Eifel maar lakes over the last 60,000 years and compared flood behavior with regional riverine flood data covering the past 1000 years. Multi-centennial flood cycles persisted throughout the Holocene with durations of flood-poor periods significantly decreasing around 3700 years ago due to human activity in the Eifel region. Holocene flood frequency peaked in the 13th and 14th centuries during the medieval agricultural revolution. Late Pleistocene flood phases occurred during the Younger Dryas and Heinrich stadials and represent surface runoff events in cold and dry climates. As flood behavior is strongly affected not only by increased water supply but also by soil stability and erosion processes in the catchment area, flood phases reflect shifts in the prevailing climate conditions and vegetation cover, either through natural steppe formation or human impact.