In recent weeks, heavy rainfall has left record accumulations of water. At the beginning of September, an Isolated Depression at High Levels (DANA) left up to 172 liters per square meter and the flooding of rivers such as the Alberche, in Aldea del Fresno (Madrid), which caused significant material damage and several deaths.
Storm Aline shattered the records just a month later. In the capital of Madrid, it had not rained so much for more than 130 years, according to the records of the State Meteorological Agency (Aemet).
Both are extreme phenomena, which are repeated with increasing frequency in our country. "Fortunately, these types of extreme events or megafloods occur very occasionally, but they can happen anywhere," and that makes them "very difficult to predict," explains Luis Mediero, professor at the Polytechnic University of Madrid, to EFE.
The challenge for the scientific community is to be able to prevent phenomena such as megafloods, so that cities are more prepared and the impact of the damage can be less. In this sense, a study published in Nature Geoscience maintains that these effects can be estimated from observations of previous floods, information that would help implement the necessary measures to defend the population from these events.
"Until now, these types of studies had not been done because a very extensive database is needed from a sufficiently large area, in which a few floods of this type have taken place," Mediero, co-author of the study, told the agency. article.
The study, led by Miriam Bertola, from the University of Vienna (Austria), has analyzed river flow data recorded at 8,000 points across Europe between 1810 and 2021, and has identified 510 megafloods.
Some of them took place in Spain, such as the one in the Almanzora River (Almería) in 1973, a flood that left ten dead in the area, or the one that affected the town of Orihuela (Valencia) in 2019, which left almost 500 liters accumulated. and caused the Segura River to flood.
Outside of Spain, the article mentions some of the most notable events recorded in central Europe, such as the flooding of the Rhine in Germany in July 2021, caused by heavy rains in the west of the country, in some areas of Belgium and in the Netherlands. and Luxembourg and that left more than 200 dead and million-dollar losses.
The article explains that regions with similar hydrological characteristics tend to produce very similar extremes across the continent and that 95.5% of the observed megafloods could have been predicted "based on previous events in similar locations."
According to the authors, the study of these megafloods could provide an indication of the magnitude of the floods that could be expected in other places in Europe with similar characteristics.
In his opinion, this information "would help emergency services to be aware that something like this could happen, and to explain to citizens what they have to do, and to implement the necessary preparation measures to reduce the damage of these floods." .
