On 5 August 2022, a debris flow occurred at the Rochefort stream in La Palud, in the municipality of Courmayeur, which invaded, with mud and large boulders, the carriageway of the road that leads to Val Ferret, damaging the bridge it crosses the stream itself but without consequences for the people and vehicles that were about to pass, thanks to the automatic switching on of two special traffic lights. The landslide also damaged the aqueduct that serves the Municipality of Courmayeur, causing a few days of disruption during the holiday period, as also reported by the national media.
In 2017, by the will of the Valle d’Aosta region, a monitoring and alarm system was installed on an experimental basis at the bridge over the Rochefort, capable of promptly interrupting traffic in both directions in the event of a debris flow. via two traffic light systems. The system, called ALMOND-F (ALarm and MONitoring system for Debris-Flow), was installed along the stream a few tens of meters upstream from the road bridge. Starting from 2019, once the experimental phase was completed, the system was taken over at an administrative level by the Municipality of Courmayeur.
The ALMOND-F system is an excellent example of fruitful collaboration between public research, local administrations and private enterprise as its implementation demonstrates the synergy between the Research Institute for Hydrological Protection (CNR-IRPI), developer of the EAGLE algorithm -DFO (EArly Ground-vibration Learning of Debris-Flow Occurrence) capable of recognizing debris flows on the basis of ground vibrations (seismic waves) produced by the moving material and detected by geophones and Siap+Micros S.p.A. who oversaw the development of the system starting from the design and electronic implementation up to installation, configuration, remote surveillance and maintenance.
On 5 August 2022, the ALMOND-F alarm system worked regularly and effectively, activating the traffic lights and interrupting traffic a few (2÷3) minutes before the lava flow invaded the bridge and roadway. The system also reported the occurrence of the event via e-mail and SMS to the local authorities in real time, also taking a sequence of photographs of the bridge before and after the arrival of the lava flow, thus showing the debris deposited and the conditions of the road after the event, before any field inspection.
It should be noted that, in the previous five years of operation, the system has always been found to function correctly, without ever producing false alarms.
Update of 09/26/2022: we report an article published by the Dire news agency.