Environmental Controls of InSAR-based Periglacial Ground Dynamics in a
Sub-Arctic Landscape
Abstract
Periglacial environments are characterized by highly dynamic landscapes.
Freezing and thawing lead to ground movement, associated with
cryoturbation and solifluction. These processes are sensitive to climate
change and variably distributed depending on multiple environmental
factors. In this study, we used multi-geometry Sentinel-1 Synthetic
Aperture Radar Interferometry (InSAR) to investigate the spatial
distribution of the mean annual ground velocity in a mountainous
landscape in Northern Norway. Statistical modelling was employed to
examine how periglacial ground velocity is related to environmental
variables characterizing the diverse climatic, geomorphic, hydrological
and ecological conditions within a 148 km2 study area. Two-dimensional
(2D) InSAR results document mean annual ground velocity up to 15 mm/yr.
Vertical and horizontal velocity components in the East–West plane show
variable spatial distribution, which can be explained by the
characteristics of cryoturbation and solifluction operating differently
over flat and sloping terrain. Statistical modelling shows that slope
angle and mean annual air temperature variables are the most important
environmental factors explaining the distribution of the horizontal and
vertical components, respectively. Vegetation and snow cover also have a
local influence, interpreted as indicators of the ground material and
moisture conditions. The results show contrasted model performance
depending on the velocity component used as a response variable. In
general, our study highlights the potential of integrating radar remote
sensing and statistical modelling to investigate mountainous regions and
better understand the relations between environmental factors,
periglacial processes and ground dynamics.