Permafrost landform dynamics in high mountain environments: a multi-sensoral approach to assess rockglacier evolution
Permafrost, defined as lithospheric material whose temperature remains below 0 °C for two or more consecutive years, occurs in many high mountain regions of the European Alps. Observed and projected high rates of changes of atmospheric, earth surface and subsurface conditions in these regions will i...
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| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
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Remote Sensing Laboratories, Department of Geography, University of Zurich
2016
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| Online Access: | https://www.zora.uzh.ch/id/eprint/135289/ https://www.zora.uzh.ch/id/eprint/135289/1/20172900.pdf https://doi.org/10.5167/uzh-135289 |
| Summary: | Permafrost, defined as lithospheric material whose temperature remains below 0 °C for two or more consecutive years, occurs in many high mountain regions of the European Alps. Observed and projected high rates of changes of atmospheric, earth surface and subsurface conditions in these regions will influence the state of permafrost and, therefore, inflict a strong impact on processes and landforms controlled by permafrost conditions. This may, in turn, become potentially hazardous to critical infrastructure as well as human habitat and economic sectors. Rockglaciers – common landforms in alpine periglacial regions that develop due to creeping of perennially frozen, unconsolidated material – serve as important indicators to describe the impacts of a warming climate on high mountain permafrost: Their short-term and long-term evolution represents the only feature of high mountain permafrost to be visually observable and can therefore be assessed by a variety of scientific surveying and monitoring methods. This dissertation aims to contribute to an improved understanding of rockglacier evolution combining kinematic and sediment controls by using multi-sensoral remote sensing data. The foundation of this approach are multi-temporal digital elevation models derived from airborne and terrestrial remote sensing techniques. In order to apply them reliably in high mountain environments for the assessment and quantification of landform structures and processes, this dissertation conducts a comprehensive accuracy assessment of multiple remote sensing products. These multi-temporal digital elevation models are subsequently used to quantify sediment production, transport dynamics and changes therein in high mountain periglacial systems. A cascading, systemic model is developed in order to describe and quantify sediment transfer rates and derive energy fluxes in such systems. Periglacial slopes are characterized by rockglaciers, ice-cored moraines and/or solifluction lobes and are often closely connected to glacial and ... |
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