IDC Natural Hazards in Mountain Regions

Johannes Branke

Observation and Modeling of Cascade Processes at the Reissenschuh (Schmirn, Austria)
Supervising board members: Barbara Schneider-Muntau, Bernhard Gems, Margreth Keiler, Martin Rutzinger, Thomas Zieher

The natural hazard process of deep-seated gravitational slope deformation (DSGSD) poses multiple threats to infrastructure in mountain regions, but also secondary processes like rockfall and debrisflow within the DSGSD cascade system have to be considered. The PhD project of Johannes Branke applies an interdisciplinary approach to investigate these process cascades linked to DSGSDs in an alpine catchment. As primary investigation site the DSGSD below the summit of Reissenschuh (Schmirnvalley, Tirol, Austria) was chosen. Existing earth observation time series will be extended using differential global navigation satellite system (DGNSS), terrestrial laserscanning (TLS) and photogrammetry. The resulting displacement time series in combination with geotechnical field and laboratory analyses will be applied to geotechnical process models identifying triggers and assessing slope stability. Regarding the secondary processes numerical modelling of gravitational mass movement processes and debrisflows with their respective run-out events will be conducted.

Xiaoru Dai

Stability of submerged slopes
Supervising board members: Wolfgang Fellin, Michael Strasser, Barbara Schneider-Muntau, Jasper Moernaut

Slope failures can have serious consequences, e.g. trigger tsunamis. The PhD candidate Xiaoru Dai focuses her research on the understanding of landslide mechanisms with different failure criteria, and the validation in some real case studies. In her PhD project, the stability is investigated by limit equilibrium method, finite element limit analysis and strength reduction method in finite element calculation. The findings from real case studies help to clarify possible triggering mechanisms of landslides by comparing the results and the observed sliding surfaces in actual situations.

Andrea Franco

A multidisciplinary approach for landslide-induced impulse waves assessments in natural mountain basins from a cascade analysis perspective

Supervising board members: Bernhard Gems, Barbara Schneider-Muntau, Jasper Moernaut, Michael Strasser, Markus Aufleger

The PhD project of Andrea Franco focuses on an interdisciplinary approach for studying and analyzing landslide-induced impulse waves in natural mountain basins from a cascade analyses perspective. The main goal is to explain the necessity to assess this kind of phenomenon and how a multidisciplinary approach concerning different sciences is useful and mandatory in this topic. The first part of the research focuses on studying past landslide-tsunami events and verifying the available possibilities in recreating such complex phenomena. With the increase in computational power over the last decades, numerical modelling approaches are commonly used to virtually simulate the landslide process and wave dynamics. The second part focuses on generating a simple methodology for assessing the magnitude of potential landslide-induced impulse wave’s attenuation in mountain lakes. The method is based on analytical equations; final results describe the near-shore impulse-wave magnitude in terms of flow depth at the shoreline. The findings carried out from this research significantly contribute to a better understanding of complex phenomena such as landslide-induced impulse waves in mountain natural basins, the influence of external triggering factors, and the downstream consequences.

Stephan Fuhrmann

Dating of rock slope failures and rock scarps using novel and classical optical dating techniques
Supervising board member: Michael Meyer

Recently, a new Optically Stimulated Luminescence (OSL) dating approach, making use of the remnant luminescence signal in rock surfaces, has been successfully applied to geological features and archaeological artefacts, which have previously been considered as being not amenable to numerical dating. The PhD project of Stephan Fuhrmann is based on such an OSL rock surface dating approach and will combine this novel dating approach with a fundamentally new way of reading out the optical information (and thus age) from rock surfaces containing feldspar minerals (i.e. 2D mapping using a EMCCD camera set-up). This state-of-the-art optical dating approach is combined with classical geological fieldwork to determine the age of rock slope failures and rock scarps and to observe bed load transport in bedrock river channels and braided (i.e. glacier influenced) rivers.

Clemens Hiller

Changing debris cover on Eastern Alpine glaciers: Quantification and hydrological impacts
Supervising board member: Stefan Achleitner

Glaciers and permafrost are retreating in the wake of climate change and are causing a rapid transition from glacial to deglacial conditions with highly intensified geomorphic processes in the proglacial zones and freshly deglaciated areas. The Hidden.ice project investigates the hydrological impact of supraglacial debris deposits in the transition zone from glacier ice to proglacial areas in Austria. The PhD candidate Clemens Hiller focuses his research on the dynamics of bedload transport and the coarse sediment budget in the forefield of the Jamtalferner glacier (Silvretta range, Austria). By capturing present proglacial sedimentary dynamics and the behaviour of high alpine fluvial systems in rapidly changing environments, subsequent future developments can be anticipated.

Jan Pfeiffer

Topographic LIDAR monitoring and modelling of a deep-seated landslide for evaluating nature-based stabilization measures
Supervising board members: Martin Rutzinger, Johann Stötter, Barbara Schneider-Muntau

Continuous and slow moving deep-seated landslides threaten human needs and infrastructure in mountainous areas. In this context the PhD project of Jan Pfeiffer focuses on deepening the understanding of their complex behaviour and assessing their hydro(geo)logical driver. Remote sensing analyses, in-situ measurements, hydrogeological monitoring as well as the exploitation of hydro-climatological and geotechnical modelling approaches are exploited in order to efficiently support planning of mitigation measures (e.g. nature based solutions).

Roshanak Shafieiganjeh

Requirements for the longevity of landslide dams in the Alpine region from a geotechnical and hydraulic perspective - Case-study-based data survey, modelling and hazard assessment
Supervising board members: Bernhard Gems, Marc Ostermann, Barbara Schneider-Muntau, Michael Strasser, Markus Aufleger

Landslide dams are recognized as the natural phenomena occurred when a landslide blocks a watercourse in narrow valleys causing the formation of a lake upstream of the landslide deposit. Detailed field studies on single cases and inventories are accounted as two approaches dealing with this phenomenon. In the PhD project of Roshanak Shafieiganjeh a GIS-based inventory of Eastern-Alps landslide dams including 73 cases is created. In the rest of this project, the main focus will be on numerical modelling of the Obernbergersee landslide dam. The leading aim will be to reconstruct the internal structure of the dam based on the geotechnical properties and hydraulic field measurements. At the end, the flood hazard due to the possible failure of the dam will be assessed.

Anna-Katharina Sieberer

Continental indentation in analogue models: Internal deformation and tectonic evolution of the Dolomites Indenter
Supervising board members: Hugo Ortner, Hannah Pomella, Barbara Schneider-Muntau

At present, the relationship between deep-seated mantle dynamics and their control on the geometry and internal deformation of the Adriatic Indenter remains unsolved. In the PhD project of Anna-Katharina Sieberer (FWF funded), a compilation of existing and a collection of new and comprehensive structural data along major faults, in combination with crustal to lithospheric scale physical analogue modelling sets out to unravel the 4D tectonic evolution of the eastern Adriatic Indenter, the Dolomites Indenter. Findings from physical analogue modelling will be combined with basic numerical modelling in order to get an integrated understanding of the continental indentation process. As part of the AlpArray initiative, with its focus on seismological investigations of the subsurface, this project provides crucial data for an integrated geodynamic model of Alpine convergence.