Monitoring Swiss alpine snow cover variations using digital NOAA-AVHRR data

Abstract

Within a research project and the programm for a Hydrologic Atlas of Switzerland, charts of the extent and the variations of the snow cover in Switzerland for two hydrologically and meteorologically different years were derived from digital NOAA-AVHRR data. During the two years, 32 satellite scenes were classified using supervised classification techniques. For the generation of the snow cover charts, up to 12 categories (several sub-categories for vegetation, water, snow, and clouds) were used. The final results were thematic maps differentiating between snow covered and non-snow covered (aper) areas. The snow cover charts were geocoded to the Swiss reference system using a ground-control-point approach allowing the superimposition onto a Digital Elevation Model @EM) and a digital boundary map of Switzerland within a Geographic Information System (GIS). Based on this data set, the snow coverage and its variations as well as the snowline for the two years under investigation were determined for several river basins in Switzerland. Furthermore, snow cover depletion curves for the two ablation periods, separately for several elevation zones, were generated which were necessary for snowmelt runoff computations in the RhineFelsberg basin using the SRM Model.

Spatiotemporal Dynamics of Snowline Altitude and Their Responses to Climate Change in the Tienshan Mountains, Central Asia, during 2001–2019

“…Regional SLA and its inter-and intra-annual variability are key characteristics that indicate temporal variation in snow cover and duration of snow melt, and help in assessing the hydrologic cycle balance [15]. For the estimation of snow-covered area and its temporal evolution, SLA can be used as an input for hydrological modeling or validation of snow model simulations [16,17]. Besides, SLA estimates can be applied to remove clouds from satellite snow cover products [18,19].…”

Investigating spatiotemporal patterns of snowline altitude at the end of melting season in High Mountain Asia, using cloud-free MODIS snow cover product, 2001–2016

“…The concept of snowline estimation varies with the applications. In hydrological applications, the snowline is identified as the boundary separating snow-covered areas from snow-free areas (Kaur et al, 2010;Parker, 1997;Seidel et al, 1997), for estimation of snow covered area and its temporal evolution, which is hence used as an input for hydrological modeling (Holzer et al, 1995;Martinec et al, 2008), or for validation of snow model simulations (Turpin et al, 1997;Zappa, 2008). And, the snowline altitude estimates have also been applied as an alternative method for cloud removal in satellite snow cover products (Gafurov and Bárdossy, 2009;Parajka et al, 2010).…”