Abstract ID: 3.13088 | Accepted as Poster | Poster | TBA | TBA

Austria is experiencing a rapid climate warming, particularly in its alpine regions. Due to rising temperatures and changing precipitation, droughts are increasing and placing therefore additional stress on vegetation. It is evident that we need to improve our understanding of how vegetation will respond to a warming climate, climate extremes, and abrupt changes. Therefore, the monitoring of vegetation phenology demands the availability of high-resolution, accurate and reliable datasets over Austrian alpine regions. The Copernicus Sentinel satellites provide high resolution observations which can be used to retrieve vegetation information. Visible and near infrared methods such as the Copernicus Land Monitoring System Sentinel-2 High Resolution Vegetation Phenology and Productivity (HR-VPP) dataset are most used. A novel approach to monitor vegetation dynamics is to use Synthetic Aperture Radar (SAR) backscatter observations which are sensitive to both structure and water content of vegetation. The Copernicus Sentinel-1 satellite operates at C-band providing data over Austria since 2014. Studies have shown its sensitivity to vegetation dynamics as well as soil moisture, snow cover and terrain which might challenge the retrieval of vegetation information over mountainous regions. We will present the first steps in retrieving vegetation dynamics information from SAR observations from Sentinel-1 C-band and SAOCOM L-band across various topographic landscapes in Austria. SAOCOM L-band observations will be investigated in preparation for upcoming L-band missions such as ROSE-L. In addition, preliminary results on the retrieval of vegetation phenology information from Sentinel-1 and the potential of laser scanning derived 3D point cloud data for the description of the vegetation structure will be shown. Specific focus will be over the mountainous Long-term Ecological Research (LTER) site Zöbelboden in the Kalkalpen, Austria, where in situ gross primary production and dendrometer data will be used as reference. Over the LTER sites the Sentinel-1 based data will be compared to the existing HR-VPP dataset from Sentinel-2. The work is part of the EO4VegetationDrought project, funded by the Austrian Research Promotion Agency, where the goal is to bring together multi-frequency satellite Earth Observation datasets and laser scanning, with high quality in situ data from the LTER Sites to improve vegetation monitoring capabilities in Austria.