Alpine Snow Cover and Glaciers in Relation to Altitude from Advanced Satellite Monitoring

Advanced methods of Landsat-TM data processing were used to map periodically the seasonal snow cover and glaciers. The test basins are located in western, eastern and southern Swiss Alps. In the basins of the rivers Rhône at Sion (3371 km2, 488-4634 m a.s.l.), Rhine at Felsberg (3249 km2, 562-3614 m a.s.l.) and Ticino at Bellinzona (1515 km2, 220-3402 m a.s.l.) relations were derived between the snow coverage and altitude at different stages of the snowmelt season. From these curves, the snow coverage at a desired altitude and the elevation of the statistical snow line at different dates can be read off. The decrease of the areal extent of snow on glaciers is slower in comparison with glacierfree areas. The snow line in the basin Rhône-Sion is lower than in the other basins throughout the season. Precision snow cover mapping and an adequate evaluation of data are needed for runoff modelling and winter tourism, in particular with regard to global warming.