Il Maltempo It hits hard and hurts in Emilia-Romagna, in Tuscany, in Veneto. In the south as in the north, with events that chase each other and pile up in the news.
"It happens and will happen this year, next year, in ten years. Because the problem of geological instability in Tuscany, as in all of Italy and I would say in much of southern Europe, is now chronic."
This was reported to Agenzia Dire by Nicola Casagli, geologist, professor at the University of Florence, president of the OGS (National Institute of Oceanography and Experimental Geophysics) and member of the major risks commission that supports the Civil Protection.
The issue goes back a long way and is linked to “two equally important factors”: climate change and massive land consumption. The first has changed the face of rainfall.
In general, looking at the annual averages, “it rains less, but more violently and concentrated in restricted areas”. And here Casagli gets straight to the point: “The events that are happening and that will happen in the coming years will be of such violence that they will put any territory in crisis, regardless of the works that can be done.
Because when 200, 300, 400 millimeters of rain fall in a few hours, roughly half the rain that falls in Florence in a year, there is no territory that can handle it no matter how much it can be controlled”.
This “is bad news”, a fact that “however also contains some positive aspects: we no longer expect recurrent floods like the one in Florence in 66. Which was not only the flood in Florence, but also in north-eastern Italy. I mean, things this big and widespread will not be impossible, but rarer”.
However, to stay in Tuscany, “events like in Livorno in 2017, in Campi Bisenzio in 2023, in Marradi in 2023 and again in 2024, are now on the agenda”.
Then there is the second factor with the same specific weight as the first, land consumption. "We have built too cheerfully and casually everywhere, in landslide-prone areas, floodplains, river floodplains, on unstable banks and slopes, on volcanoes and faults. And we continue to do so because land consumption, monitored every year by Ispra, shows no signs of decreasing".
And here the mechanism jams, above all for an economic question: "Building on virgin land costs much less than recovering an abandoned area".
Precisely for this reason, if on climate change the process of reversing the trend, to which the policies of the countries of the world should be linked, "is very long", on land consumption "there is more possibility of acting, for example by making it more convenient, also with institutional incentives, to build on the built and demolish many disgusting things done in the past to rebuild in a more appropriate manner".
This is the picture described by one of the leading experts on the field: "There is a combination of two factors and one is very difficult to influence. On the other, however, we could act. All the rest are palliatives. For goodness sake - he specifies - everything is good, but when it rains 2-300 millimeters of rain ... ".
the key, therefore, "is to learn to live with risk. And I quote the United Nations: at the top of the Sendai Protocol is precisely understanding the risk of disasters. We need to understand how a river, a landslide, an earthquake works. And make citizens understand, that if they do so, they can defend themselves better.
Let me explain: the 226 millimeters of rain that fell on the Tuscan coast are a frightening amount. There is no territory that can resist. But people can organize themselves to suffer as little damage as possible, saving their lives.
“Even today, in fact, most of the victims, as well as the injuries to people, happen due to wrong behavior. I'll give you a typical example: it starts to rain heavily. There's a weather alert, but I don't pay too much attention and go out to move the car.
This is the stupidest thing to do: when I have more than 50 centimeters of water on the ground the car starts to float; when I have more than 80 the doors no longer open and I remain trapped.
If we taught this in driving school, a lot of people would be saved. People die in cars during floods, rarely at home. That happens too, but it's much more difficult."
However, the reflection (and controversy) on the warning system is urgent and cyclical again. A knot that Casagli believes must be untied by systematizing and better organizing the data that the machine already has for the most part.
“Until 2010-12 the alert was incomprehensible to the population. Then the colored codes were introduced: yellow, orange and red. There, with the traffic light system, people began to understand it. And I can testify, also on the basis of the experience gained in the commission for major risks, that the plan has saved many lives”. The point, rather, is in the way in which the data is handled.
“Satellite monitoring is already incorporated into the national warning system.” Alongside these there are “networks of ground sensors. Ten, fifteen years ago they cost a lot of money,” now that expenses have significantly dropped “we can spread hundreds of thousands of them across the territory. This already happens,” however “all the activities are a bit uncoordinated.
There are many projects, but there is no organic and integrated system capable of bringing together all the actors to be able to play together like in an orchestra. There are many soloists, a lot of data and information, but we are still a bit far from making them play together, in a harmonious way. Here, this is what is needed”.
Article published on 25 September 2024 - 15:31
