4th Swiss Geoscience Meeting, Bern 2006 Remote Sensing Modelling and Visualization of the Permafrost Distribution in the Hautes Alpes Calcaires

Small Scale permafrost repartition models are often constructed with empirical methods based on the observation of regional lower permafrost limits. In this contribution geomorphologic units are derived from analysis and interpretation high-resolution aerial photographs. A classification of satellite images considering these units is then performed to model permafrost distribution. Based on properties of exposition, slope and topography, three permafrost-related geomorphological landforms were observed: an active rock glacier, a moraine with gelifluction lobes and the lowest part of a high altitude talus slope. The first two landforms are characterized by discontinuous permafrost occurrence; talus slopes close to the lower limit of alpine discontinuous permafrost are characterized by important ice amounts at the bottom (Lambiel 2006). These three geomorphologic landforms are easy to detect by high-resolution aerial photographs: validation of the areas has been made directly on field by geomorphologic cartography in the highes