Predicting megafloods in Europe may now be within reach by examining historical data from areas with similar hydrological features, researchers have found.
This finding has implications for the future of flood defence strategies across the continent.
Megafloods are extremely large and rare floods that drastically exceed the normal expectations for an area, often causing widespread destruction and loss of life. They are typically much larger than the biggest floods for which a region usually prepares.
In a study published in Nature Geoscience, Miriam Bertola and her colleagues analysed river discharge data from about 8,000 gauging stations throughout Europe, covering a period from 1810 to 2021.
Their research identified 510 instances of megafloods, revealing a trend where regions with similar water-related characteristics experience extreme flooding events of similar magnitudes.
The findings suggest that 95.5 per cent of these megafloods could have been anticipated by looking at previous events in comparable locations.
The study indicates a promising approach by adopting a continental-scale perspective when assessing flood risks, rather than limiting the focus to local catchment areas.
By implementing this strategy it may be possible to predict the magnitude of potential megafloods in Europe, based on data from areas with hydrologically similar characteristics.
The research indicates effective prediction and preparedness for such disastrous events might be achieved by sharing flood data across national borders, with European locations as reference points.