National water availability. BIGBANG ISPRA: decreased by 20% in the last thirty years

The trend recorded in Italy in terms of availability of water resources is definitely a downward trend. In the last climatological thirty years 1991-2020, with a value that amounts to more than 440 mm, the availability of water decreases by 20% compared to the historical reference value of 550 mm., about 166 km3 recorded between 1921-1950.
Long-term estimates (1951-2021) also show a significant reduction, around 16% less than the historical average annual value.
This reduction, due to the impacts of climate change, can be attributed not only to the decrease in rainfall, but also to the increase in evaporation from bodies of water and transpiration from vegetation, due to the increase in temperatures.