Geomorphological, nivo-meteorological and seismic analysis of snow avalanches release areas in Central Italy, January 2017

This paper concerns the geomorphological, nivo-meteorological and seismic analysis of snow avalanches release areas in Central Italy in January 2017. The whole analysis was performed using GIS supports. The largest magnitude snow avalanches, occurred in the Central Apennines in January 2017, were obtained following a photo-interpretation work carried out on high resolution satellite images. From these events it was possible to extract the snow avalanches release areas. In addition, two algorithms for PRA (Potential Release Areas) delineation have been implemented and their results were compared with real release areas extracted from photo-interpretation work. Starting from DEM SRTM (30 m), the geomorphological analysis was developed. It led to a statistical characterization of main topographic attributes (elevation, slope, aspect and curvature) of snow avalanches release areas. Nivo-meteorological release areas analysis was based mainly on data of cumulative snow precipitation, during the period 15-18 January 2017, deriving from meteorological model. In particular, the geomorphological and nivo-meteorological analyses were carried out on the totality of release areas and on Sibillini Mountains, Laga Mountains, Gran Sasso Massif, Majella Massif and Sirente Velino Mountains release areas. For each mountain sector, release areas were also characterized by differentiating between Adriatic and Tyrrhenian side. Seismic characterization was performed taking into account the most relevant earthquakes occurred in January 2017 and evaluating accelerations that affected snow avalanches release areas. In addition to these earthquakes, release areas have been characterized on the basis of PGA reported by the INGV seismic hazard map, considering an exceeding probability of 10% in 50 years. In this case, release areas were analyzed differencing for three selected mountain sectors: Sibillini Mountains, Laga Mountains and Gran Sasso Massif. Also in this case, for each mountain sector, release areas were characterized by differentiating between Adriatic and Tyrrhenian side.