The recent floods that hit Valencia and theEmilia-Romagna they are the latest tragic example of the growing vulnerability of the Mediterranean regions in the face of extreme climate phenomena.
In Valencia, the scenario was apocalyptic: On October 29, in a few hours, the water exceeded 600 millimeters in some locations. The rain turned streets into raging rivers, sweeping away cars, destroying bridges and submerging homes under a sea of mud and debris. The devastation has spread relentlessly, and the death toll continues to grow hour by hour, exceeding 200, with thousands missing. A disaster that generated a profound sense of despair, helplessness and anger among the survivors, amplified by the serious underestimation of the danger by the Spanish civil protection.
Even theItaly experienced a similar situation with the recent flood that hit theEmilia Romagna. Although the human toll was less tragic than that of Spain, with only one victim recorded, the heavy rainfall – around 350 millimeters – put a strain on a region known for its hydrogeological vulnerability and already hit in 2023 by extreme meteorological phenomena. Here, the water reached uncontainable levels, infiltrating everywhere, inundating homes and the drainage system, designed to manage floods, proved inadequate in the face of such intense rainfall. This tragedy was also affected by insufficient regional investment in water infrastructure and the lack of maintenance of canals and embankmentswhich gave way under the pressure of an incessant mass of water.
The meteorologist told us about it Pierluigi Randi of Ampro (Professional Weather Association)
What are the common factors between the floods in Valencia and that in Emilia Romagna?
«The floods in Emilia-Romagna and Valencia are examples of intense meteorological phenomena that share some particular atmospheric conditions. A common element is the presence of depression vortices, i.e. areas of low pressure which, detaching themselves from the flow of the main currents, remain trapped and stationary. These low-pressure vortices are often accompanied by unusually warm air masses.
In particular, the high surface water temperatures of the Mediterranean Sea play a key role in these events. When the sea is warmer than normal, it provides more energy to the atmosphere. This “extra” energy makes the storm systems generated by low pressure vortices more intense, favoring the formation of more abundant and long-lasting rainfall. Recent studies have shown that rising temperatures in the Mediterranean can increase rainfall by up to 25% compared to normal. This percentage is significant and explains why floods have become more frequent and devastating in areas such as Emilia-Romagna and Valencia. The heat and humidity present in these areas amplify storms, which become stronger and more persistent, leading to very intense rainfall and high potential for hydraulic risk.”
Why were there so many victims in Valencia?
«In Valencia, the management of the emergency was not adequate. The Spanish meteorological service had already issued a red alert the previous day, but it was underestimated by local and regional authorities. Citizens received the warning messages with considerable delay, while many people were still on the streets or outdoors when the flooding occurred. This contributed to a particularly severe death toll. With more careful management, human losses could probably have been reduced.”
Could the damage be contained in Emilia-Romagna?
«The perfect prevention system does not exist: in the last two years there have been four floods in Italy, two in 2023 and two in 2024. The situation is serious, since the territory was designed for a climate of the past. Today the rainfall is very different and adaptation interventions are necessary in the area. The catastrophic event of 2023 was the third most serious meteorological event in the world and shocked the territory of eastern Emilia and Romagna. Since then, the region has become more fragile and vulnerable, so much so that even minor events can cause damage that they once would not have caused.
Huge investments and numerous interventions will be necessary, as the waterways have turned into channels with a reduced capacity to let the water flow away. Maintenance is essential to protect against ordinary floods, but over the years it has not been optimal. Furthermore, Emilia Romagna is in first place for soil consumption, which is therefore increasingly impermeable and incapable of absorbing and retaining water. If no changes are made to the landscape in the coming months and years, the hydraulic risk will continue to increase.
Furthermore, both Valencia and Emilia Romagna, in addition to being highly urbanized, are both areas that present a further unfavorable factor: the surrounding reliefs that cause rainfall to remain stagnant. In Emilia Romagna, the Apennines influence the climate, while in Valencia the mountain ranges to the west hinder the movement of masses of water vapor coming from the sea, causing intense and persistent precipitation.”
