A new simple topo-climatic model to predict surface displacement in paraglacial and periglacial mountains of the European Alps: The importance of ground heating index and floristic components as ecological indicators

• Published in: Ecological Indicators
• Main Authors: Stefano Ponti, Nicoletta Cannone, Mauro Guglielmin
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2021
• Subjects: Surface displacement model; Slope; Ground heating index; Permafrost degradation; Vegetation rooting depth; Ecological indication of movement; Ecology; QH540-549.5; permafrost
• Online Access: https://doi.org/10.1016/j.ecolind.2020.106889; https://doaj.org/article/a40fe9014db543528bb606e1510ac568

Landscape evolution is occurring at rapid rates in alpine areas in response to recent climate warming, also due to the susceptibility and the heterogeneity of these environments. Here we present a prediction model of surface displacements that takes into account both topographic and climatic variables. Observed points of surficial displacements have been associated to non-climatic (altitude, slope, solar radiation, till deposit type, deposit age, vegetation coverage) and climatic (days of snow permanence, ground surface temperature index, ground heating index, ground cooling index) variables through a general regression model in the European central Alps.The model output shows the importance of slope and ground heating index (GHI) – an estimation of the amount of energy transferred to the ground, to predict surface displacements independently from the type of considered processes. In particular, the general regression model shows that steep zones with high GHI are more susceptible to undergo periglacial and paraglacial processes producing surface displacements. As expected, slope is fundamental to trigger processes such as gravitation, nivation, solifluction and their interactions. The results of our model emphasize the key role of GHI, highlighting the importance of climate in controlling the surface displacement. Indeed, in areas in which GHI is higher, the ground can remain snow free for a longer time and snow melting can be faster, the former favoring more runoff and slopewash, and the latter promoting the saturation of the deposits consequent to a higher intensity of solifluction and/or mass movements processes.Within the study area, the sites with the largest displacements (>35 cm) were detected where permafrost degradation occurred since 1990. This permafrost degradation process could remain one of the main triggering factors of future surface displacements. Our results confirm that when movement involves material with coarse texture (pebbles and boulders) exceeding the rooting depth, only tolerant ...