Analysis of snow cover in landslide prone areas: The example of Tena Valley, Central Pyrenees, Spain

In this work, we analyze the characteristics of snow cover using two space borne products (Level 1C and Level 2A) provided by the SPOT4 Take 5 Initiative. The principal aim of this initiative is to evaluate the benefits of Sentinel 2 acquisition mode before its launch. We processed SPOT4 images acquired from February 2013 to June 2013 over the site of Midi-Pyrénées (South West). The Normalized Difference Snow Index (NDSI) and Fraction of Snow Cover (SCF) are calculated on all dataset and the snow surface map and its evolution over the time is obtained. The distribution of snow cover is slightly larger using the Level 1C than in the Level 2A data. This information will be merged with climatic data and snow depth ground measures in order to derive the melt rate, the snow cover depletion rate and the snow water equivalent, and to analyze the groundwater level variations and their interaction with the landslide activity.