6. Workshop Alpine Hydrologie

Basic UAS applications (Unmanned Aircraft Systems) have long been indispensable for data acquisition in high mountains. Yet, far more is possible today than roughly a decade ago: a growing range of sensors and a reliable EU legal framework (the „Specific“ category, BVLOS) now enable a much wider variety of applications – from the surface, through the subsurface, to beneath the water. Their greatest advantage lies in the temporal and spatial flexibility of the systems.
Drawing on examples from glacier, permafrost and cryosphere research, this contribution illustrates the breadth of today’s UAS methods.
Photogrammetry flown by copters that launch automatically from permanently installed hangar systems captures snow and glacier surfaces at high temporal resolution – in principle several times a day and with centimetre-level accuracy. As the hangars are operated entirely via remote online control, both safety and efficiency rise markedly. Thermal sensors are particularly promising for snow and permafrost, enabling measurements where surface conditions are ambiguous – for instance to trace ice beneath debris.
UAS-borne LiDAR comes into its own in complex topography, in poor light and beneath vegetation, delivering data for small-scale questions where aircraft-based surveys reach their limits.
Ground-penetrating radar (GPR) carried on larger copters makes long profile lines flyable even across heavily crevassed glacier terrain; for example, on the Hallstätter Glacier, 52 km of profiles were recorded, yielding ice thicknesses of up to 70 m and the remaining ice volume.
Finally, echo sounders on UAS open up water bodies that are difficult or impossible to survey by boat – such as glacial lakes – enabling safe and efficient depth surveys.
The talk draws these experiences together into an assessment of where UAS now stand in hydrology and cryosphere research, what accuracies and ranges are realistic, and where the approach usefully complements conventional techniques – efficiently, flexibly and safely, especially in hard-to-access terrain.