Regional scale classification of landforms and understanding their surface processes using digital elevation model-derived thematic maps in Arctic landscapes

With the onset of global warming and the subsequent thawing of permafrost, the Arctic is set to see a substantial change in the occurrence of surface processes. In permafrost and periglacial regions our current understanding of landform process, morphology, and landform interaction with climate has come from local empirical studies. However, there are few studies which have attempted to automate the mapping of landform processes and to understand their spatial distribution at a regional scale. The aims of this research are to demonstrate (1) the efficacy of using generalised linear models (GLM) in classifying an Arctic landscape into landform types, using only the characteristic surface features (geomorphometric parameters) of the landforms. (2) Quantify the extent of landform processes in the Arctic. (3) Understand how geomorphometric parameters can help to explain the processes controlling the formation of Arctic landforms, at a regional scale. To train the GLM, nine landform types were mapped from a 400 km2 study site in the glaciated valley of Adventdalen, Svalbard. Each landform type was mapped and digitised using a combination of satellite imagery and a geomorphological map. Eight geomorphometric parameters were derived for each landform type using a 10 m spatial resolution digital elevation model (DEM). For each landform type the classifier was trained on 70% and tested on the other 30%. Selected landscapes in Svalbard and Alaska were classified using the trained GLM. The highest accuracy scores for the GLM were achieved using a combination of three geomorphometric parameters: surface roughness, slope gradient, and relative local relief. These results provide an insight into the possible mechanisms driving the formation of Arctic landforms and demonstrate the applicability of the model for use in slope instability studies and landscape classification in other Arctic regions.