The Italian summer of drought

The drought in Italy continues, especially in the Po Valley. Along the Po river, the situation is particularly serious: after the water level had begun to rise as a result of rainfall from recent months, values ​​equal to or lower than historic lows were recorded in all points of the river where the flow is recorded (the quantity of water transported per unit of time), due to temperatures generally being higher than the seasonal averages and lower rainfall. The largest Italian river is going through «the worst crisis of 70 years to date», reports ADBPo (the Permanent Observatory on water uses of the Po River District Basin Authority) defining it as «historic». The same applies to the tributaries of the Po from the Apennines, as well as for the groundwater of Piedmont and Lombardy.

With the end of the period in which spring rainfall could have been expected – which there has been but not enough to mitigate the effects of months without precipitation – and the significant increase in temperatures in recent weeks (up to 2°C more than seasonal averages in the Po Valley), it is expected that the drought will last the whole of summer 2022 and, in order to address these consequences, the Council of Ministers convened on 4 July 2022, declaring an emergency in the regions of the Po basin and the Eastern Alps: Piedmont, Lombardy, Veneto, Friuli-Venezia Giulia, Emilia-Romagna.

The most serious situation therefore remains that of the Po basin; however, the problem does not only concern the Northern regions of the Country: in general, all regions bordering the Tyrrhenian Sea are currently suffering the effects of drought. In Lazio, for example, the levels of the Tevere and Liri rivers, as well as of the Bracciano and Nemi lakes, have significantly reduced; for this reason, Acea Ato 2, the company that manages the water services in Rome and central Lazio, was forced to ask the Region for permission to increase water withdrawals from the Pertuso source (one of the sources of the Aniene), to avoid interrupting supplies in the Alban Hills area.

Precipitation has also decreased at an alarming rate in Tuscany, in the face of an increase in average temperatures: the flow of the Arno river is equal to 27 per cent of the average, so much so that the ANBI (Observatory of the National Association of land reclamation, irrigation and land improvement consortia) defines it as «now a stream». In Campania, there is a risk of drought linked to the low levels of waterways, while in Basilicata, Puglia and Calabria, the high temperatures from recent weeks have caused strong evaporation in the artificial water reserves.

The rainfall that occurred in Italy between the end of March and the end of May was not sufficient to bring the situation to a less critical threshold, i.e. to avoid the effects of the prolonged lack of rain on water supplies and on agriculture. In fact, drought is caused by long-term climate conditions, and can often not be overcome by repeated rainfall of stormy but inconstant conditions: when the soil is dry and compact due to lack of water, as in this period, when there is too much rainfall, it is unable to absorb all the water and a significant amount will run off.

The spring season, which it was hoped could reduce the accumulated deficit, instead confirmed the negative forecast, also resulting in poor rainfall, with values ​​that place it in third place only behind 2003 and 2017. It is true that with summer approaching, temperatures increase, but this year, already in the second half of May, higher temperatures than usual have been recorded, such as to cause an extraordinary increase in the evaporation of water present in the soil, putting ecosystems under stress.

More than 30 per cent of the national agricultural production is grown in the Po Valley, and drought could cause major problems for the sector, especially for sunflower, maize, wheat and cereal crops, as well as forage for animal feed. The situation could worsen further with hail, which, during the hot months, often accompanies the little rainfall, aggravating the damage already caused by drought to crops. In the medium and long term, it is estimated that 40 per cent of Italy’s irrigated areas will be affected by drought categorised as «severe-extreme», reports the Drought Observatory.

«We can already say farewell to the late tomato as well as to many vegetables, whose crops, given the lack of water necessary for irrigation, cannot even begin to grow», reported the Italian Farmers Confederation (CIA), which foresees a reduction of between 30 and 40 per cent for melon and watermelon crops, and 50 per cent for maize and soya crops. No short-term improvements are expected, as neither heavy rainfall nor significant drops in temperatures are expected; especially in the agricultural sector – the sector most affected by the problem – a lot will depend on the water-saving strategies that will be carried out in the next few months: at best, lower yields will be obtained; at worst, it will not be possible to fully guarantee the process of collecting.