The lack of water affects above all the North-East

There was a time when September 1 started all over again. Conventionally, it is the first day of the hydrological year, the period (which goes from September to August) in which rainfall is measured and balanced. “The ‘memory of the current year’ should begin in September, because the snows melt in August, everything empties. Because it was assumed that it would rain. Instead, in April there will be two years full of drought”, he explains Luca Pitcher, of the Research Institute for Hydrogeological Protection (Irpi) of the Cnr. And instead 2022/23 started already in the red, due to the record drought that hit northern Italy above all last spring/summer, to which must be added this year’s deficit. The conditions with which we are heading towards summer which are worse than those of 2022, to which must be added the scarcity of snow.

In April, Brocca added up and mapped the rainfall in the previous seven months by processing data from Eumetsat satellites. The reddish colors show where and how much it rained less than the average. The entire Po basin is vermilion, the whole Po Valley it’s dark, Veneto And Friuli Venezia Giulia they go towards brown/black, like Versilia. And the satellite images of the last few weeks certify how the beds of rivers are like Po and Ticino (taken from the ASI Cosmo-SkyMed satellite and from the ESA Sentinel 2), are already showing the shoals and could soon become, as already seen last summer, tongues of land furrowed by the memory of a large river.

In Veneto and Friuli Venezia-Giulia the amount of rain falling day by day is -400 millimeters compared to the average, almost 300 in Liguria, over 200 in Sicily, Lombardy and Emilia Romagna. There are very strong local differences, for example, in the south of Calabria, where the lack of rain is felt above all in the province of Reggio and Catanzaro. The worst month: February. “Now it has rained in the South, there has been a recovery – underlines Brocca – while in Veneto and Friuli Venezia-Giulia, which are the basin of Italy, the deficit is more marked and is felt precisely because, together with Liguria, they are regions where it rains a lot”. Even ESA certifies it, after “the second mildest winter” on record, most of theEurope is in debt for water. The crisis is also being felt in the North, in a long strip that goes from the Pyrenees to the Baltic republics.

The trouble is that, apart from April, we have the dry season ahead of us, and this deficit is destined to remain so or, rather, worsen. Barring surprises, which however represent an exception, such as that of May 2019, one of the rainiest in memory: “That year we were in similar conditions, then in May it rained a lot, and the deficit was recovered – he adds the Irpi expert – but, in fact, that too was an exceptional situation in which there were also floods”. In these years, which are getting hotter and drier, localized storms are increasing instead, discharging, in a few hours, the quantity of water that usually drops in the space of a few months.

And by dint of extremes, we have come to hypothesize the water rationing in areas that were once rich in water, to having to reduce the production of crops that require copious irrigation, and to the reduction of the production of hydroelectric energy: there is much less water flowing or to precipitate. Irpi has developed and made available, on its website, a simple tool for visualizing the consequences of drought for Po Valley (water catchment area of ​​the Po) by modifying, like on an audio mixer, a few simple parameters (precipitation, air temperature, initial conditions of soil humidity and the equivalent in snow water), to evaluate the impact on the use of the water for economic (agriculture and industry) and civil activities.

And it is those areas where water drives the economy, as well as the turbines, at the expense: “The situation in the north is alarming because a lot of it is used, from the rice fields in the Vercelli area to the kiwi in Romagnawe are used to being full of water, and with regard to the production of energy, we must consider that the lower the level of a basin, the less energy is produced” reasons Brocca. We have seen a plastic example with the emergence from the lakes shrink and dry rivers, wrecks from the Second World War and archaeological remains.In Garda, the isthmus that connects the mainland to the Isola dei rabbits has resurfaced, from lakes of Cancano, in Valtellina, the remains of the submerged village after the construction of the dam have seen the light again. Terna has estimated a 37.7% drop in hydroelectric energy production for 2022, and given the scarcity of rain and snow, the first months of 2023 have seen an even greater drop.

But if it is still possible to hope for a rainy May, not even with months of above-average rainfall will they give us back the snow cover that is missing, which is a bit like the piggy bank that assures us a little comfort, a parachute which, however, recent years, it is more and more laundry.

The Cima Foundation (International Center for Environmental Monitoring) has estimated a snow deficit of 63% until the end of March. That for the basin of the Po it rises to 66 and 69 for the entire Alpine arc. It is precisely this that is most worrying, given the crisis of 2022.

The snowfalls of January and February were not sufficient to recharge the snow reserves in order to cope with the mild temperatures of March and the backlash of winter in April certainly could not have put a patch on it.

“The snow never recovers and the deficit has worsened compared to last year as well” reports Brocca. Less snow melting means even less water available for rivers, lakes, power plants and agriculture. A blow, a vicious circle if one considers that drought itself means that when there is no water that comes down from the sky, more water is needed for irrigation.