While the impacts of global warming and current heat waves on glaciated areas have been in the focus of media reporting in recent weeks, also the dynamics of rock glaciers as part of the periglacial environment are strongly affected by changing climate. Rock glaciers are creep phenomena of mountain permafrost and an integral part of the high-alpine mass storage and transport cascade system. Monitoring their surface and sub-surface dynamics is important as it improves our understanding of how the changing climate affects the stability of their slopes, potentially leading to destabilization and increased rock fall activity. Moreover, rock glaciers are large solid water reservoirs and the thawing of their ice affects discharge and can also lead to sudden acceleration of rock glacier movement due to sliding on a sub-surface water layer.
Within the AHK-4D project, we continually monitor topographic change at the alpine rock glacier Äußeres Hochebenkar in Austria. Based on multitemporal and multisource 3D point clouds at up to two-week acquisition intervals, we are developing methods to quantify the magnitudes and frequencies of individual processes of topographic change over varying timescales. Check these methods out – they might be interesting for you!
This video provides insights into the project’s goals.
UAV-derived point clouds have thereby shown great potential as input for methods for 3D/4D change analysis of rock glaciers because they are able to overcome common challenges of ground-based techniques (e.g. occlusion, limited spatial coverage, time-intensive data collection). In this context, collaborative research and research-oriented education (project E-TRAINEE) is being carried out with the Institute of Geography of the University of Innsbruck.
More impressions on the most recent field campaign can be found on our Twitter Account (@3DGeoHD)
Recent publications featuring methods for 3D/4D surface change analysis at the rock glacier are listed below:
Zahs, V., Winiwarter, L., Anders, K., Williams, J.G., Rutzinger, M. & Höfle, B. (2022): Correspondence-driven plane-based M3C2 for lower uncertainty in 3D topographic change quantification. ISPRS Journal of Photogrammetry and Remote Sensing. Vol. 183, pp. 541-559. DOI: 10.1016/j.isprsjprs.2021.11.018.
Zahs, V., Winiwarter, L., Anders, K., Bremer, M. Rutzinger, M. Potůčková, M., Höfle, B. (2022): Evaluation of UAV-borne photogrammetry and UAV-borne laser scanning for 3D topographic change analysis of an active rock glacier. International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XLIII-B2-2022, pp. 1109-1116. DOI: 10.5194/isprs-archives-XLIII-B2-2022-1109-2022.
Ulrich, V., Williams, J.G., Zahs, V., Anders, K., Hecht, S., Höfle, B. (2021): Measurement of rock glacier surface change over different timescales using terrestrial laser scanning point clouds. Earth Surface Dynamics. Vol. 9, pp. 19-28. DOI: 10.5194/esurf-9-19-2021.
Winiwarter, L., Anders, K., Höfle, B. (2021): M3C2-EP: Pushing the limits of 3D topographic point cloud change detection by error propagation. ISPRS Journal of Photogrammetry and Remote Sensing, 178, pp. 240–258. DOI: 10.1016/j.isprsjprs.2021.06.011.
Williams, J.G., Anders, K., Winiwarter, L., Zahs, V., Höfle, B. (2021): Multi-directional change detection between point clouds. ISPRS Journal of Photogrammetry and Remote Sensing. Vol. 172, pp. 95-113. DOI: 10.1016/j.isprsjprs.2020.12.002.
Zahs, V., Hämmerle, M., Anders, K., Hecht, S., Rutzinger, M., Sailer, R., Williams, J.G., Höfle, B. (2019): Multi-temporal 3D point cloud-based quantification and analysis of geomorphological activity at an alpine rock glacier using airborne and terrestrial LiDAR. Permafrost and Periglacial Processes. Vol. 30 (3), pp. 222-238. DOI: 10.1002/ppp.2004.
To keep up wih our work on these methods and datasets, stay tuned for updates here or on Twitter.