Recent area and volume loss of Alpine glaciers in the Adda River of Italy and their contribution to hydropower production

We found large glacier reduction, with an area change of −25.41% during 1991-2007, and −30.5% during 1981-2007. Volume change during 1981-2007 was −1353 × 106 m3 ± 27%. The mean thickness change was −14.91 m. The mean annual volume change of the Sondrio glaciers was about −52 × 106 m3 y−1 of ice, or ca. −47 × 106 m3 y−1 of water. We then computed the glaciers' contribution to 25 hydropower plants located in the studied area. For this purpose we divided the study region into two zones. While in the first, Eastern most region (R1) a large share of hydropower is provided by liquid precipitation, in the second Western region (R2) ca. 1/2 of the total water for hydropower is provided by solid water, i.e. snowfall and ice melt. Our results display that in areas like Region R2, where a large share of hydropower production depends upon ice melt, the expected future lack of water under glaciers' down wasting may affect energy production, and requires adaptation strategies.