Dynamic Slope Geomorphology and vulnerability in Nunavik, Canada

Several villages and parks in Nunavik (northern Quebec, Canada) are located near high reliefs whose slopes are subject to frequent gravity movements, in particular avalanches. The IPEV DeSiGN project has provided conclusive results on this point, which have been valued in the international literature.

The documentation of the implementation of the created models, their dynamics and the risks that the hazard poses to a constantly growing local population, and to the increasing number of tourists in the parks, is required.

The first objective of the DeSIGN2 project is to continue to improve the knowledge of slope geodynamics and their activity over the long, medium and short terms in a context of global warming: the results of DeSiGN had shown large intra- and inter-annual variability in avalanche triggering in particular; further data collection is essential.

The second objective is the characterization of the hazard and the situations of vulnerability, in order to define and quantify the risk represented by gravity hazards. The DeSiGN project had underlined the multiplicity of meteorological situations of avalanche and mass movement triggering on the slopes; the continuation of the acquisition of results with DeSiGN2 is necessary to obtain the most exhaustive possible panel of risk situations.

Finally, the third objective is to propose also a reasoning at the watershed scale by highlighting the sediment connectivity between the slopes and the river, which is the only source of drinking water for the population, but also an essential food source through fishing. However, the temperature increase degrades the permafrost, increases the turbidity of the surface water by injecting more and more sediment and organic matter into the system. The source, transfer and deposition zones must therefore be identified in the watersheds studied. To achieve these objectives, we favour a methodology based on both field work in geomorphology (morphometry, analysis of land and river forms) and stratigraphy (analysis of Holocene accumulations) and on laboratory analyses (dating, sedimentology, dendrochronology) coupled with the diachronic analysis of aerial and satellite images.