Georesearch Forschungsgesellschaft

Abstract Monitoring snow distribution in alpine terrain is critical for hydrology, avalanche safety, and climate research, yet traditional surveys are costly, hazardous, and spatially sparse. We assess a gondola-mounted, low-cost Light Detection and Ranging (lidar) system (MOLISENS) for repeated snow monitoring in Real-Time Kinematics (RTK)-denied mountain environments. The system fuses lidar, Inertial Measurement Unit (IMU), and standalone Global Navigation Satellite System (GNSS) using a Simultaneous Localization And Mapping (SLAM) algorithm to generate 3D point clouds along a fixed aerial-lift transect at Hoher Sonnblick, Austria. Six winter runs (March 2023) were processed and compared with summer Unmanned Aircraft System (UAS)-photogrammetry. Intra-system repeatability between same-day scans reached centimetre precision (weighted standard deviation 0.010 m; 95% within $\pm$ 0.006 m), supporting detection of daily to seasonal changes in snow thickness along the route. Absolute agreement with the UAS reference was limited to decimetre scale, primarily due to registration and standalone GNSS uncertainties rather than sensor range noise. Performance degraded over feature-poor snowfields, and manual segment merging was labor-intensive; consequently, quantitative analyses were restricted to well-constrained segments. Despite these limitations, the results demonstrate the feasibility of gondola-mounted lidar for cost-effective, repeatable snow-thickness mapping.

At the end of the 1980s, the design, testing and subsequent manufacture of steel rockfall protection barrier systems began around the world.To ensure that these barriers can effectively stop the dynamic impact of rockfall, several guidelines have been introduced worldwide since 2001.The level of knowledge about the behaviour of rockfall protection barriers, and the current regulations related to their testing and remaining capacity after impact differ ay global level.In 2019 an Innosuisse-sponsored 3-year research project was awarded to WSL Institute for Snow and Avalanche Research SLF together with Geobrugg, from the industry side, for rockfall barriers full-scale testing, to deepen the knowledge about the variability of the actual behaviour of these protection barriers.The results lead to additional tests to the existing European certification procedure, allowing a better quantification of the energy capacity of the protective surface of rockfall barriers.

Since the 19th century, the warming rate in the European Alpine region has been twice as high as the average global rate. Warming-related permafrost degradation has been shown to cause a reduction of bedrock bearing capacities, potentially leading to the destabilization and eventually to the failure of high-alpine infrastructure. The presented study investigates permafrost-related changes of bedrock properties and their stability-relevant effects on high-alpine infrastructures. The Kitzsteinhorn summit and its highly frequented cable car station (3029 m a.s.l., Austria) is home to the interdisciplinary Open Air Lab Kitzsteinhorn (OpAL), where the consequences of climate change, based on a long-term monitoring of surface, subsurface and atmospheric parameters are investigated. In a rock-ice mechanical model, degradation of permafrost causes changes in rock fracture toughness and rock friction, affects ice fracturing and creep as well as the behavior of rock-ice interfaces. A first numerical distinct element model of the mechanical behavior of rock slope and the infrastructure was set up, based on OpAL datasets and a civil engineering assessment of the cable car setup. By conducting a thorough rock mechanical model sensitivity analysis, it was tested how individual model parameters affect the rock slope stability below the cable car summit station. The accurate knowledge of the most sensitive parameters and their empirical variation range generates a better process understanding of destabilisation in permafrost-affected rock walls. This facilitates efficient stabilization measures for affected high-alpine infrastructures. Here we show, that the stability of infrastructure on permafrost-affected bedrock is not only passively determined by mechanical changes in the underlying frozen rock mass, but infrastructure also actively affects thermal conditions and rock stability in a relevant way.

Abstract Many problems in engineered rock faces involve evaluation of the efficiency of rockfall mitigation measures, specifically rockfall dams, embankments and catch nets. Existing rockfall trajectory models are not suited for this purpose because they do not consider the non‐linear dynamics of rock motion, which is highly dependent on rock size, shape and impact configuration. In this paper, we discuss the application of the new 3D rockfall modelling tool Ramms::Rockfall, which computes rock‐ground interactions using hard‐contact impact mechanics. The model is applied to evaluate the effectiveness of a rockfall bank at the Geobrugg/WSL test site in Walenstadt, Switzerland.