Abstract ID: 28.7373 | Accepted as Poster | Poster | 2025-02-28 12:45 - 14:15 | Ágnes‐Heller‐Haus/Small Lecture Room

In the frame of the project “Agile Arvier. La cultura del cambiamento”, funded by the Italian PNRR plan (Piano Nazionale di Ripresa e Resilienza) and aimed to achieve a better knowledge of the alpine environment in every sector with respect to the changing climate, some studies involving satellite applications have been conducted. In particular, monitoring the glacial and periglacial environments by means of Earth Observation (EO) techniques is a growing field of interest for risk assessment in mountainous areas. By applying remote sensing indices, such as the Normalized Difference Water Index (NDWI), to multispectral data from the Copernicus Sentinel-2 satellite, maps of glacial lakes have been generated, enabling the identification of new potentially hazardous water bodies. Thanks to the spatial resolution of the satellite acquisition (10 m), precise measurements of the surface of the water bodies can be tracked across entire summer seasons from 2019 to present, considering a 500 m distance buffer from the glaciers’ outlines in Aosta Valley (IT). To ensure data quality, a cloud removal algorithm based on Sentinel-2 Scene Classification Layer (SCL) information has been applied to the multispectral datum, in order to filter the available datasets. Afterward, the filtered data have been used to compute the NDWI index. Water body maps were derived by applying a dynamic threshold, set to 75% of the maximum range of the NDWI values within the buffered area. A comparison with previous manual inventories allowed for the monitoring of known lakes, while an iterative process using sequential images was implemented to identify newly formed glacial lakes. Using this procedure, a seasonal monitoring of a large area is possible, observing unstable environments without the need of in-situ surveys, especially for known sites where glacial lake outburst floods (GLOFs) occurred in the past.