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In Switzerland, natural hazards such as avalanches, landslides, rockfall, debris flows, flooding and forest fires can cause considerable damage. Through our research and services, we help to protect people from natural events.


In Switzerland, 23 people are killed on average each year by avalanches alone; flooding and mass movements cause damage amounting to an average of CHF 300 million per year. As the population continues to grow, more and more buildings are located in at-risk areas.

As such, we look into how different natural hazards arise, how far, how quickly and how vigorously they develop, and how people can protect themselves accordingly. This may be through effective spatial planning, reliable forecasting or technical protective measures. We lay the scientific foundations for risk analysis and for evaluating whether protective measures and warning systems are effective and economical.

As well as scientific and engineering research, this requires economic and social analysis given that major events present politics, government and society with the challenge of finding widely accepted and economically viable risk reduction strategies.

Observation and simulation

In order to understand the processes of natural hazards in detail, we run experimental setups which are unique worldwide. As part of field experiments, we observe the dynamics of avalanches, debris flows, rockfall and landslides under realistic conditions. In some cases, we also initiate them for experimental purposes (avalanche test site).

Thanks to this measurement data, we now understand better than ever how these natural hazards arise, and are able to simulate the processes within them in increasingly precise computational models. This is useful for developing protective measures and hazard maps.

Contending with climate change

When glaciers melt and permafrost thaws as a result of climate change, this threatens to set in motion enormous quantities of soil, rock and scree – a significant danger to lower lying settlements and transportation infrastructure. This is why we are focusing on mass movements in alpine regions that are triggered by climate change as part of the strategic research initiative "Climate Change Impacts on Alpine Mass Movements", which is set to run from 2017 to 2020.

Forewarned and informed                                                                               

When it comes to warning and prevention systems, we play an important role nationally and occupy a leading position internationally: in winter, the avalanche warning service at the WSL Institute for Snow and Avalanche Research SLF publishes the well-known avalanche bulletin twice a day, while our hydrologists are involved in warning the public about instances of flooding and severe drought.

Forest fires present a real threat in the already dry southern alpine valleys. We record and analyse forest fire events, develop methods and concepts to evaluate the risk of forest fire, and determine the consequences for ecosystems such as protection forests.

We make our data and findings available to the public on internet platforms so that crisis managers can access the information quickly in an emergency.



Ein Bord mit einigen kleinen Bäumen steht in Flammen. Die im Vordergrund sichtbaren grossen Bäume sind noch unversehrt.

Forest fires

We examine factors that increase the risk of forest fires and develop tools for predicting them.

Umgestürzte Bäume liegen in einer Lichtung.

Weather and Climate Extremes and Drought

We study weather and climate extremes in Switzerland, for example droughts. This is how we create the basis for dealing with them.

Ein Murgan stürzt sich in einem Bachbett hinunter.

Debris flows and bedload

Mountain torrents on steep terrain can sweep away destructive loads of rock. We investigate these processes to improve protection measures.

Zwei mit mehreren Personen besetzte Schlauchboote fahren durch die von Hochwasser überfluteten Gassen in einer Stadt.

High water levels and flooding

Flooding causes a huge amount of damage in Switzerland. We have been laying the foundations for flood forecasting and warnings for over 100 years.

Ein Stein prallt in einer Staubwolke in ein Steinschlagnetz.

Rockfalls and landslides

We research rockfalls, rock slope failures, hillslope debris flows and landslides to give people and infrastructure in valleys better protection.

Vor der Gemeindeverwaltung in Brienz, einem grossen Holzhaus, türmen sich Schlamm- und Geröllmassen von einem Murgang. Verschiedene Autos liegen kreuz und quer davor.

Dealing with natural hazards

Responding to and managing natural hazards has a long tradition in Switzerland. Through research and services, we help to reduce the risks.



Snowshoeing is becoming more and more popular, but the same rule applies as with other winter sports: beware of avalanches.

Net barriers against debris flows in the Illgraben (VS)

In many cases, nets offer a viable alternative to concrete structures as protection against natural hazards, indicates a new publication.

The SLF issued its first avalanche bulletin on 21 December 1945. Major changes and continuous improvements have been made over the years.

Who is behind the avalanche bulletin and what do avalanche forecasters do in summer? In the video interview, three of them give exciting insights.




L’attività di osservatrice o di osservatore per il WSL Istituto per lo studio della neve e delle valanghe SLF (osservatore SLF) è particolarmente variegata: dalla misura della neve fresca, passando per varie osservazioni sul territorio e fino al rilevamento di un profilo stratigrafico sul pendio. Queste attività vengono descritte dettagliatamente nel presente manuale (Manuale dell’osservatore SLF). Il Manuale dell’osservatore SLF si rivolge quindi in prima linea alle osservatrici e agli osservatori SLF. I metodi standard e in parte applicati a livello internazionale possono però trovare applicazione anche al di fuori dell’attività di osservatore SLF. Il presente manuale si limita a descrivere le operazioni di rilevamento dei dati. Informazioni dettagliate sull’inserimento dei dati si trovano nei relativi canali di feedback.

Die Arbeit als Beobachterin oder Beobachter für das WSL-Institut für Schneeund Lawinenforschung SLF (SLF-Beobachter) ist ausgesprochen vielseitig. Sie reicht von der Messung des Neuschnees über verschiedene Beobachtungen im Gelände bis hin zur Aufnahme eines Schneeprofils im Hang. Diese Tätigkeiten sind im vorliegenden Handbuch (SLF-Beobachterhandbuch) detailliert beschrieben. Das SLF-Beobachterhandbuch richtet sich damit in erster Linie an die SLF-Beobachter. Die standardisierten und teilweise international gebräuchlichen Methoden können aber auch ausserhalb der Arbeit als SLFBeobachter Anwendung finden. Das vorliegende Handbuch beschränkt sich auf die Beschreibung der Datenerhebung. Anleitungen zur Dateneingabe finden sich in den jeweiligen Rückmeldekanälen.

Le travail comme observatrice ou observateur pour le WSL Institut pour l’étude de la neige et des avalanches SLF (observateur SLF) est extrêmement varié. Il va de la mesure de la neige fraîche au relevé d’un profil de neige sur un versant, en passant par différentes observations sur le terrain. Ces activités sont décrites en détail dans ce Manuel d’observation du SLF. Celui-ci est donc principalement destiné aux observateurs du SLF. Les méthodes standardisées et parfois utilisées au niveau international peuvent également être appliquées en dehors du travail comme observateur SLF. Le présent manuel se limite à la description de la collecte des données. Vous trouverez des consignes pour la saisie des données dans les différentes plates-formes de retour d’information.