Interactive 3D terrain — Google Earth-style descent
Watch the globe spin into the study area: the view starts at planetary scale, zooms across Europe and Austria, and finally settles over Hohe Tauern with satellite imagery draped on real elevation tiles. Once landed, drag to rotate, right-click drag to change pitch, and use the controls to zoom or go fullscreen. A marker highlights the Großglockner (3,798 m), Austria's highest peak.
Geographic Setting
Hohe Tauern National Park is situated in the central part of the Eastern Alps in Austria, covering the federal states of Carinthia (Kärnten), Salzburg, and Tyrol (Tirol). The area covered by the park is 1,856 km², which makes it the largest national park in the Alps and one of the largest protected natural areas in Central Europe. The national park is distributed along and on both sides of the main Alpine ridge, encompassing the area from valley bottoms at approximately 700 m a.s.l. up to the peak of the Großglockner, the highest mountain in Austria, at 3,798 m a.s.l. The park's status as a protected area and the fact that most of it remains untouched by human activity make it a perfect site for studying natural snow cover.
Topography
The topography of Hohe Tauern National Park is defined by its high and steep reliefs formed under the influence of Pleistocene glaciers. The territory of the national park covers one of the largest tectonic windows in the Alps – the Tauern Window, which includes a variety of metamorphic rocks of the Penninic nappe. Many peaks in the district rise to more than 3000 meters above sea level, and hundreds of glaciers cover the area. The digital topographic model used is a slope layer derived from the ALOS PALSAR 12.5 m resolution radar satellite. All data were projected to WGS84 / UTM Zone 33N for the Sentinel-1 and Sentinel-2 satellites used from 2018 to 2025.
Climate
The climate of Hohe Tauern National Park varies from oceanic in the west and north to more continental in the inner-alpine east. It is strongly determined by altitude since annual mean temperatures are close to 0 °C at the timberline (1800–2000 m a.s.l.). Annual precipitation amounts to 2000 mm or more in exposed western and northern mountain tops, with a significant part falling as snow in the form of heavy snowstorms in winter (October–May). Alpine snow cover in the region usually starts to form in October and is maximum in February–March, being gradually depleted in spring and summer. Snow depth and snow cover duration decreased significantly at low and mid-altitudes during the last decades (Schöner et al., 2009; Olefs et al., 2020). The melting of snow cover in high-altitude regions is one of the main sources of river runoff in Austria, particularly for the Salzach, Drau, and Inn catchments (Hanzer et al., 2018).
Elevation Zones
Due to the strong dependence of snow accumulation, ablation, and snow state on altitude, the study area was stratified according to elevation using the ALOS PALSAR DEM into four elevation zones:
- Zone I (<1,500 m): the lower valley and mountainous area with discontinuous and seasonal snow cover and a relatively short snow season;
- Zone II (1,500–2,000 m): the lower sub-alpine area with a stable seasonal snowpack and a distinct spring snowmelt peak identified in both optical and SAR data;
- Zone III (2,000–3,000 m): the alpine area with deep and prolonged snowpack dominating the snow cover extent during the cold season;
- Zone IV (>3,000 m): the high-alpine and glacierized area with a continuous and perennial snow cover and the largest challenge for optical remote sensing due to frequent cloudiness and low sun angles during winter.