In order to consider the hazards associated to the mountain permafrost, the Municipality of Bagnes (VS) has commissioned the IGD to map the potential distribution of this phenomenon. The choice of a technique taking into account the strong spatial discontinuity of permafrost was necessary. Support Vector Machines (SVMs) have been chosen because of their ability to produce robust classifications. A dataset composed of 15 variables was selected for this model. Some were simply calculated and extrapolated from a digital elevation model (resolution 25x25 meters), whereas others have been extracted from the Swisstopo's primary surface map and from a rock glacier inventory of the region. The dataset was completed by empirical measurements obtained during field campaigns. This innovative methodology has produced a model in line with the reality. A comparison with the official BAFU's permafrost map has shown that the model provides a higher level of accuracy. A sectorial analysis was subsequently brought to light the main features of several areas potentially sensitive to hazards related to periglacial processes.

Project location