Investigation and preliminary assessment of the Casamicciola landslide in the island of Ischia (Italy) on November 26, 2022

• Published in: Landslides Vol. 20; no. 6; pp. 1265 - 1276
• Main Authors: Romeo, S., D’Angiò, D., Fraccica, A., Licata, V., Vitale, V., Chiessi, V., Amanti, M., Bonasera, M.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.06.2023; Springer Nature B.V
• Subjects: Agriculture; Buildings; Casualties; Catchment area; Catchment basins; Civil Engineering; Debris flow; Detritus; Displaced persons; Earth and Environmental Science; Earth Sciences; Economic importance; Field investigations; Geography; Geology; Geomorphology; Heavy rainfall; Landslides; Landslides & mudslides; Mathematical models; Natural Hazards; Numerical models; Rainfall; Recent Landslides; Risk management; Roads; Socioeconomic aspects; Vulnerability; Ischia; Debris flow; Ischia Island; Casamicciola landslide; Rainfall-induced landslide; Landslide assessment
• ISSN: 1612-510X; 1612-5118
• DOI: 10.1007/s10346-023-02064-0

On the 26th of November 2022, as a consequence of heavy rainfall, diffuse landslides were triggered in the Northern sector of Ischia . The present study investigated the main features of the debris flow originated in a small catchment basin falling within the Casamicciola Terme Municipality. The debris flow, triggered around 05:00 a.m. from the Northern slope of Mt. Epomeo, travelled about 850 m before impacting a populated area. In detail, it affected about 30 buildings causing 12 casualties and several injured, more than 200 people displaced, and severe damages to the road network, resulting one of the most destructive landslide events occurred on the island. This multidisciplinary work, aimed at a preliminary assessment of the event, considered geological and geomorphological evidence collected during a field investigation, as well as environmental data, to set up numerical models both for landslide triggering and propagation. Along the pre-existing channel, a marked erosional behaviour was observed with a maximum removed thickness of about 5.5 m, whilst the material deposition largely occurred after the impact on buildings. The total volume mobilised by the debris flow was estimated in approximately 40,000 m 3 . Considering the geological and geomorphological conditions, as well as the high vulnerability and the socio-economic importance of the area, a careful monitoring and risk management activities in the next months will be necessary.