Dangerous glaciers in Valais

Monitoring and inventory of dangerous glaciers in the canton

As part of the GL² consortium, comprising CREALP and geoformer igp AG, the Canton of Valais has commissioned us to update and monitor the canton’s inventory of hazardous glaciers. This inventory is an essential tool for identifying and assessing natural hazards linked to the rapid changes in glaciers in the context of climate change.

To date, around fifty glaciers are included in this inventory. The associated hazards are varied and can have significant consequences for communities, infrastructure and activities located downstream. The phenomena being monitored include, in particular, serac falls, the formation and evolution of glacial lakes, the presence of pockets of water within or beneath glaciers, and the risk of debris flows caused by the mobilisation of large quantities of sediment in glacial valleys.

Monitoring is based on an approach combining several complementary sources of information. Field observations are carried out regularly, as are aerial surveys to identify the most significant changes. Feedback from external observers, such as local authorities, mountain hut wardens or mountain professionals, also constitutes a valuable source of information. Finally, remote sensing technologies and satellite observation enable continuous and systematic monitoring of glaciers at cantonal level.

For each glacier listed, a risk index is calculated and updated annually based on all the observations collected. This assessment enables the monitoring of changing hazards and the prioritisation of monitoring and analysis requirements.

The inventory is a dynamic tool that is constantly evolving. Some glaciers are removed from the inventory when the associated hazards disappear or when the glacier itself no longer exists. Conversely, new glaciers may be added when new potentially hazardous phenomena are observed, such as the formation of glacial lakes or the emergence of new instabilities.

The aim of this project is to ensure rigorous annual monitoring of hazardous glaciers in Valais and to maintain an up-to-date inventory, in order to contribute to the proactive and effective management of natural hazards in the Alpine environment.