Abstract
The snowpack that accumulates in the mountains every year is a precious natural water reservoir for humans, retaining winter precipitation and releasing it in spring at the right time to irrigate crops. What's more, the snowpack is a powerful thermal insulator, regulating ground temperature and conditioning the phenology of high-altitude vegetation. Climate change, which disrupts the accumulation and melting of snow cover, threatens to disrupt the functioning of mountain watersheds and ecosystems. We'll be looking at how recent advances in space observation are making it possible to characterize the evolution of snow cover and better understand its hydrological and ecological impact.