Mean snow cover duration

Abstract

The temporary storage of precipitation in short term in the form of snow cover has an important function in the water balance of the Upper Danube drainage basin. Among other factors, snow cover depends on the climate variables temperature and precipitation; thus, it is a good indicator for climate change and its impacts for water balance and economic activities. The formation and development of a snow cover is the short-term result of processes of formation and depletion that are controlled by local weather conditions. These processes have a very direct and highly sensitive dependence on the climate parameters radiation, temperature, humidity, wind and precipitation. As a signifi cant location factor, local snow cover duration SD is defi ned as the number of days with snow cover within a specifi ed period. The results obtained here with the model Snow for the spatial distribution of snow cover duration on the 1 × 1 km 2 grid are quite detailed and potentially even more accurate than statistical extrapolations from observational data on similar maps. The physical-based model Snow, which is integrated within DANUBIA, is shortly documented. Since in general the months from July to October are snow-free at elevations below 3,000 m a.s.l., only the period from November up to and including June is used for the map of snow cover duration. The resulting distribution is plausible. It illustrates not only a distinct correlation between the persistence of snow cover and elevation but also regional dependencies.