30-years (1991-2021) Snow Water Equivalent Dataset in the Po River District, Italy | Associate Writer

The Po is Italy’s longest river. It flows west to east across northern Italy, from the Alps to the Adriatic Sea, and its basin covers roughly a quarter of the country, including some of its most densely populated, agricultural and industrial areas. Water management across this basin is coordinated by the Po River District Basin Authority.

In this system, snow is a strategic water resource. Mountain areas, mainly in the Alps to the north and west and the Apennines to the south, make up about 60% of the district. Here the snowpack, the layer of snow that builds up on the ground over the winter, works like a natural reservoir: it stores water during the cold months and releases it gradually as it melts in spring and summer. This meltwater feeds rivers and streams, recharges groundwater and fills artificial reservoirs used for drinking water, irrigation and hydropower.

Knowing how much water is stored in the snow, and how this amount changes over time, is therefore essential for managing water resources wisely, especially now that droughts and water shortages are becoming more and more frequent.

A new study now helps answer this question. Researchers from the Po River Basin District Authority, the University of Trento and the Italian company Waterjade Srl have published a reconstruction of how much water was stored in the snow across the district’s mountains every day from 1991 to 2021. The key measure is the snow water equivalent (SWE): the amount of water that would be released if all the snow on the ground melted at once. The study maps SWE over the entire mountain area of the district at a resolution of 500 × 500 metres, making it the first dataset of this length and detail for the region.

The paper, “30-year (1991–2021) Snow Water Equivalent Dataset in the Po River District, Italy”, appeared in Scientific Data, a Nature Portfolio journal.