Examination of Ground Deformation Information in Alpine Terrain - The Potential of EGMS

Alpine terrain – in high and low altitudes - faces changes in stability due to climate change (permafrost and mass movements or landslides), effecting natural conditions and therefore human infrastructure. Those changes are mainly driven by changing atmospheric patterns leading to shifts in the temperature and precipitation regime. In high alpine terrain dwindling permafrost potentially results in an increasing instability. Recently several incidents of rockfalls and massive landslides were reported, e.g. the village of Brienz only narrowly escaped a fatal disaster. Especially low-lying areas or valleys are of special socioeconomic interest forming settlement areas with transport, tourism and human infrastructure. For example, an increasing number of land- and mudslide events along the “Brenner Highway” were reported by the Austrian motorway authority (ASFINAG). The highway and railway line act as a main and highly frequented transport route connecting Innsbruck (Austria) with Bolzano (Italy). Under a changing climate regime more of these incidents are expected in the near future. With the increased dynamics and probability of landslides the risk for human infrastructure and inhabitants of alpine regions could increase.

Consequently, the use of continuous and accurate ground deformation information becomes evident. EGMS, as a Pan-European service, provides validated and accurate data since 2021, therefore key information for ground deformation monitoring on a wide area basis. However, the utilisation of EGMS products in alpine terrain is not yet fully addressed due to technical plus natural constraints regarding alpine topography, climate, etc. versus the applied interferometric measurement approach.

Our analysis provides an assessment of ground deformation data on a wide area plus detail level in its temporal and spatial context and its applicability to changing permafrost and ground stability conditions. Based on EGMS products the distribution of deformation features is evaluated in correspondence to alpine permafrost index maps. An indication of potential hot spots is modelled by respective active areas and their relation to infrastructure elements and settlements. This includes the integration of auxiliary and reference data.

With this approach considerations of the distribution and temporal characteristics of deformation areas, in terms of mean velocities and deformation time series, are deduced together with spatial relations of measurement points to the objects of interest, e.g. settlements, road, railway or touristic infrastructure.

Finally, conclusions for a wide area utilisation of EGMS deformation information are drawn including the provision of an assessment of required reference and auxiliary information plus conceptualisation of an adapted and optimised monitoring approach addressing alpine geohazards.