https://www.valigiablu.it/emilia-romagna-alluvioni-come-perche-cause-danni/
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Underwater.This is how Faenza, Cesena, Forlì, some areas of the Ravenna area, some streets of Bologna ended, after the violent rains that hit Emilia Romagna and also the Marche since May 16th and which they provoked the death of 13 people, dozens missing, over 20 thousand displaced.41 municipalities were affected by the flood, 24 were flooded, 22 rivers flooded.Civil Protection he issued a new red alert for many territories of the two Regions until May 19th, both for the risk of landslides, collapses or mudslides, and for possible further flooding.
“In terms of impacts on the territory, it is probably the most serious flood effect of at least the last 100 years.In terms of extension of the areas affected and quantity of precipitation, as well as damage to multiple provinces, it is something devastating, very serious", underlines Pierluigi Randi, president of AMPRO (Professional Weather Association).“A disaster announced, but we ignored the signs,” he commented the meteorologist, Luca Mercalli.
“The scale of the devastation of the bad weather is that of another earthquake:the damages will be quantitatively smaller, but they will amount to a few billion euros", he stated the president of the Emilia-Romagna Region, Stefano Bonaccini, who he adds to have estimated damages of 1 billion euros.“As with the earthquake we will rebuild everything:we told the government that we need many resources, but also expeditious regulations, we need an extraordinary commissioner, obligations for workers, to extend deadlines, mortgage installments, lots of investments".
The agricultural sector is particularly affected - for Coldiretti there are losses of 300 million euros, while the president of Orogel, Bruno Piraccini, he spoke of crops and incomes of an entire year of work compromised – and the industrial one:numerous companies had to suspend their production for safety reasons.
The Prime Minister, Giorgia Meloni, assured maximum availability to support the affected areas, probably through a law decree, while the Minister of the Environment, Gilberto Pichetto Fratin, announced that the Government will try to activate the European solidarity fund.Meanwhile, the Deputy Minister of Economy, Maurizio Leo, announced that tax obligations for businesses and families in the affected municipalities will be suspended.
And while we begin to count the damage and undauntedly try to bring isolated or trapped people to safety, we are wondering about the causes of these extreme meteorological events and what to do to prevent or at least mitigate the catastrophic consequences.
What happened?
Since the morning of May 16, various areas of Emilia-Romagna and Marche have been plagued by torrential rain, with showers and thunderstorms, which have caused landslides, floods, flooding and inundation of coastal areas.This is the second extreme meteorological event to affect Emilia Romagna within two weeks.Between 1 and 3 May the region was in fact hit by intense rainfall.Already then there was talk of a phenomenon that was in some ways surprising in terms of scope and duration.This time, however, the event was even more intense:Almost the same amount of rain fell, but in less time and over a larger area.
In a few hours, depending on the area, between 100 and over 200mm of rain fell, "huge quantities of rain for our precipitation climatology", observe again the president of AMPRO, Pierluigi Randi:“It's the one that usually falls in an entire spring.In a century there have never been extreme events so close.The situation is truly worrying, also for the future."
The protagonist of this dramatic event "was an unusually intense Mediterranean cyclone for the month of May, born on the coasts of North Africa, moving up along our peninsula from the South starting from Sicily, and then affecting the Center-North more directly Italy", explains the meteorologist Edoardo Ferrara a Bologna Today.“Eastern Emilia and Romagna found themselves in the most dramatically disadvantaged position.In fact, the disturbance in itself was already quite violent with vigorous rainfall (peaks of over 80mm even in the upper Marche), but once it reached Emilia Romagna the rainfall was further exasperated by the so-called 'stau effect'".
In summary, a mass of low pressure, developed on the southern Tyrrhenian Sea and full of humidity, remained trapped under two high pressure areas to the West and East, stopping on the Emilia-Romagna side and continuing the disturbance in the same area.The so-called 'stau effect' was superimposed on this.When they collided with the Apennine barrier, the currents continued to rise.As they rise, the currents tend to condense even more and thus have dumped even greater quantities of rain, constantly, all in the same area.
Two other factors may have contributed to exacerbating the rainfall: explains ISPRA in a note:the strong bora winds on the coast and the rise in sea levels, again due to the strong wind, may have hindered the flow of water from the Apennines towards the Adriatic Sea, further favoring the flooding of the coastal areas.
Why were there the floods?
Emilia Romagna is among the Italian regions with the highest percentages of potentially floodable territory and population exposed to the risk of flooding, both due to its hydrographic network and the dense network of artificial drainage channels, writes ISPRA.Furthermore, Emilia Romagna it is the second region in Italy, after Lombardy, due to the spread and extension of landslides on its territory. Report on landslides in Italy.The potentially floodable areas reach 45.6% of the entire regional territory and the exposed population well exceeds 60%.The provinces with the highest percentages of floodable territory are Ravenna and Ferrara with percentages reaching respectively 80% (87% of exposed population) and almost 100% in the case of a medium flood risk scenario.
Various watercourses depart from the Apennines, usually heading towards the sea, but the extent of the rainfall and the fact that the soil was unable to absorb the water accumulated following the rainfall which occurred at the beginning of May he did yes that the water from the courses did not flow towards the sea, causing rivers to overflow, floods, floods and landslides, precisely in the most exposed areas and where a large part of the population and economic activities are concentrated.In fact, all the most affected areas are located in the plain close to the Apennines.
Added to this is a further factor, namely the composition of the soil.Alluvial plains such as the Po Valley are essentially composed of an alternation of clayey, silty and sandy soils.Clay rocks are among the most impermeable in nature and so water cannot infiltrate and ends up remaining on the surface.
Does climate change have anything to do with it?
Given that it will take time to attribute this extreme weather event to climate change, there are some elements that converge towards a role of global warming and the climate crisis.
1) There was a change in the circulation of currents.As climate physicist Antonello Pasini explains, "today, anthropogenic global warming has caused not only average temperatures to change, but also circulation in our Mediterranean:while previously the circulation was almost always in a west-east direction, now this circulation often occurs along the south-north or north-south directions".This translates into periods of 'good weather' and 'bad weather' which each last for several days in the same area.“In the case of rainfall, it therefore has time to fall more heavily on the same area, potentially creating flood conditions even if the rainfall itself is not truly exceptional.This is exactly what happened in recent days in Emilia-Romagna."
2) Recent studies show how in the Mediterranean we begin to expect cyclones are rarer but more "loaded" with precipitation and, therefore, more violent.Furthermore, the higher temperatures of the sea which are impacted by the influences arriving in the Mediterranean create the conditions for more violent precipitations.
3) Finally, there is always a greater alternation between periods of drought and others of flood.Even without the drought, the intensity of the meteorological event that hit Emilia Romagna would have caused enormous damage.However, further studies could confirm that the repeated alternation between periods of drought and flood is an effect of global warming.
Could something be done?
As in the case of floods in the Marche, last September, we questioned the real possibility of predicting an event of this severity and the state of the prevention measures adopted in recent years by the Region and Municipality to limit the impact of extreme events, which unfortunately are increasingly frequent in all latitudes.
“We have to be honest:intervening on phenomena like this is very difficult,” comment Giulio Betti, Cnr-Lamma meteorologist.“There were areas in Emilia-Romagna where, from the point of view of land management, we were also quite well placed but although the systems were prepared to receive rainfall they could not contain such a quantity of water.We must get it into our heads that we need to redesign cities and water disposal systems, as well as clearly working in a single direction to fight the climate crisis."
According to data provided by the Rendis platform of Ispra, in Emilia-Romagna have been put in the pipeline 529 projects and works from 1999 to 2022 (4.7% of the total works at national level) of which 368 have been completed (69.5%).The total amount of money allocated to prevention was 561 million:of these, 45% (258 million) was used for the completed works.
In 2015, Emilia Romagna signed the 'Subnational global climate leadership memorandum of understanding', an international protocol for the control of emissions into the atmosphere which commits the Region to an 80% reduction in its emissions by 2050.In 2018, the "Strategy for mitigation and adaptation of the Region" was approved.The document contains, in addition to an in-depth assessment of the regional emissions framework and future and ongoing climate change scenarios, a sectoral analysis of the main vulnerabilities and the actions to be taken for each physical-environmental and economic sector.
Already in the Strategy, the Region identified an increase in desertification, a greater risk of landslides and hydrogeological instability, "in relation to the easier triggering or resumption of landslides and more frequent river floods, especially in the small foothill basins connected to the urban fabric ”.In part, what happened in recent days.
Among the actions, the strategy predicts the strengthening of interventions for the adaptation of the territory, the doubling of ordinary and extraordinary maintenance activities, the maintenance and strengthening of the warning system, the fight against coastal erosion, the strengthening of the “Emilia-Romagna Weather Alert” portal (“ multimedia platform available to both mayors and all operators of the civil protection system, from the Prefectures to the regional territorial services already among the most advanced at national level", we read in the document) and actions at the level of prevention and training for " create a 'risk culture' as broad as possible at all institutional, economic and social levels" and "ensure the necessary prevention and reduce the vulnerability of territories, businesses and citizens".Finally, "all municipal administrations are invited to renew their urban planning tools, eliminating expansion forecasts and focusing the new strategy on urban regeneration that significantly increases the resilience of cities and the territory".
It is precisely on this last aspect that tip Giulio Betti:“At a prevention level, a radical change in infrastructure, sewerage and land management would be needed.Which sooner or later has to be done.When we talk about ecological and energy transition we should in fact think of an especially infrastructural transition:it is unthinkable to think of being able to deal with other phenomena like the one we are experiencing today with the infrastructure we have now."
According to Vitalba Azzollini, the PNRR could make it possible to make up for the delays accumulated in the implementation of interventions to make the territory safe, also due to an "old public administration, depleted of personnel, lacking in qualified profiles and unattractive for talent".With a recent law decree, the already existing rule on the substitutive powers that the Government can exercise in the event of failure to comply with the deadlines in the implementation of the PNRR has been modified.“Because these substitutive powers have not been activated to prevent the delays that continue to emerge or, in any case, to carry out urgent interventions”, you ask Azzollini?
And in the meantime we continue to wait for the National Plan for Adaptation to Climate Change, promptly brought up after a hydrogeological disaster but dramatically still stuck at the starting point.The increasingly pressing pace of climate change does not wait for the biblical times of the institutions and so the action plan, dating back to the last decade, becomes increasingly obsolete.
The all-Italian odyssey of the National Climate Change Adaptation Plan
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