Po Valley, intensive irrigation helps aquifers

Intensive irrigation contributes to the stability of the Po Valley aquifers , even in the presence of repeated summer droughts : this is indicated by research published in the journal Nature Water and born from the collaboration between Italy and the United States. In particular, the National Research Council, with its institutes for hydrogeological protection (Cnr-Irpi) and for water research (Cnr-Irsa), the University of Milan-Bicocca and the University of Berkeley, contributed.

The study examined the areas of the Po Valley used for agricultural purposes, analyzing the state of the aquifers on the basis of data acquired between 2002 and 2022 by NASA's Grace satellite . The data indicate that, in areas where irrigation is intensive , the aquifer levels show greater stability . This is observed despite the general decline in aquifer levels and the researchers indicate the cause in the recharge induced by the infiltration of excess water used for irrigation. The positive correlation between the quantity of water in the aquifers of the plains and the accumulation of snow in the Alps was also demonstrated.

“The research highlights the importance of understanding the water balance in agriculture , especially in a phase in which Alpine snow cover is becoming less and less predictable,” comments Christian Massari of Cnr-Irpi. For Marco Rotiroti, of the University of Milan-Bicocca, “the critical element becomes a possible winter drought, which would not allow adequate feeding of rivers and lakes and, in turn, intensive summer irrigation, which recharges the aquifers. As long as there is adequate snow cover in winter, the aquifers will be stabilized by irrigation, even in the presence of summer droughts.”