Potential Shallow Landslides 1 September 2025 Val Fontanabuona, Ligury, Italy

The database comes from the use of the PANDA (Notti et al., 2024) method to map the potential shallow landslides (PL) occurred during the extreme rainfall event happened the night of the 1st September 2025 in a central sector of Val Fontanabuona (Liguria, Italy). A pre-event image acquired on 7 September 2024 and a post-event image acquired on 1 October 2025 were used, obtained by Sentinel-2 satellites (https://browser.dataspace.copernicus.eu/), both filtered with a 30% cloud-cover threshold. Subsequently, the CloudMask layer (available in the S2 dataset) was added to filter. Then the NDVI (Normalized Difference Vegetation Index) was calculated both for the pre the post event images, to calculate its variation by using the subsequent formula: NDVIvar = NDVIpost - NDVIpre The 5-m DTM of Regione Liguria was used in order to filter the PL with the derived slope degree. In the end, to identify the PL polygons were used 2 thresholds: NDVI variation ≤ -0.15; Slope ≥ 15°; The preliminary polygons obtained by using these first thresholds were further filtered by: - Removing PLs that were within the shadows of the clouds, that were not included by the CloudMask. - Reclassifying PLs probably related to Hydraulic Processes using the distance from the polygon to the water bodies, and the percentage of area included inside the water course. Those polygons have been reclassified as HyP (Class 1). - Removing land use change (related to variations of vegetation), by using two other satellite images, one from 13 August 2024 and one from 5 August 2025. Those polygons have been reclassified as LuC (Class 2). The remaining polygons have been classified as Potential Landslides (Class 0). The polygons obtained from these filters are inside the “PL_valFontanabuona_202509001” geopackage. Then, inside “Ground_valFontanabuona_202509001” geopackage, it’s possible to find two validation points, that correspond to two geolocated ground truths based on photo and drone videos of landslides, published by the local news. Such information was used to validate the one identified by the PANDA method. Inside the attribute table, it is possible to find a field called “Validation” where there are the links to the local online news and drone flies. References: Notti, D., Cignetti, M., Godone, D., Cardone, D., & Giordan, D. (2024). The unsuPervised shAllow laNdslide rapiD mApping: PANDA method applied to severe rainfalls in northeastern appenine (Italy). International Journal of Applied Earth Observation and Geoinformation, 129, 103806. Local Team: https://www.localteam.it/video/nubifragi-liguria-frane-isolano-frazione-a-favale-di-malvaro-drone Il Secolo XIX: https://www.ilsecoloxix.it/liguria/2025/09/02/news/maltempo_frane_allagamenti_aggiornamenti-15291822/