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Snow Avalanches and Prevention

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Head: Dr. Jürg Schweizer

This research unit investigates the formation and dynamics of avalanches in order to improve the forecasting of when and where avalanche events are likely to occur and their effects. It engages in process modelling based on laboratory experiments and field investigations.

On behalf of the government, it also operates the Swiss avalanche warning service. The avalanche bulletin provides information concerning the current avalanche situation and warns the public about the avalanche danger. The data underlying the service is delivered by an extensive network of observers and automatic measuring stations. The avalanches and prevention unit develops warning and information systems for public authorities and local emergency services.

Among other key duties, the unit provides advice on practical aspects of avalanche protection, and develops methods for the risk-based management of natural hazards. The latest research and development findings are continuously being translated into practice and used in the unit's intensive teaching and training activities.

It works closely together with other SLF research units and partners in Switzerland and abroad. These include national and international research establishments, cantonal and federal authorities, as well as industry, associations, and agencies responsible for public safety and tourism.

Research groups

Snow Avalanches and Prevention

Topics

Avalanche bulletin

In its avalanche bulletins, the SLF provides information about the current avalanche situation. Its content is designed as an informed warning.

Avalanches

Research into avalanche formation, dynamics and protection is therefore a key part of our remit.

RAMMS

RAMMS is a software package that allows natural hazard processes to be evaluated and facilitates an assessment of the influences of protective...

FURTHER INFORMATION

Projects

High-precision seismic trigger system for the Vallée de la Sionne test site

The aim of this project is to develop a low power, high precision, low budget seismic trigger system with remote control. It will be used in a tailored configuration, to detect all avalanche activity at the Vallée de la Sionne test site, from release to deposition.

Prospective Management Natural Hazards SBB

Development of a method and a tool for risk indication mapping of mass movements along the railway network of SBB.

Sicher Wandern 2040

Auch in Zukunft sollen die knapp 65'000km des Schweizer Wanderwegnetzes möglichst gefahrlos begangen werden können. Eine Literatursynthese soll die für das Wanderwegwesen relevanten Naturgefahren identifiziert und Auswirkungen einer Klimaveränderung abschätzen.

Gefahrenhinweiskarten Lawinen

Flächendeckende Gefahrenhinweiskarten für Lawinen für Graubünden und Liechtenstein.

Rockfall barrier tests in natural terrain

WSL and its industrial partner GEOBRUGG are testing a new rockfall barrier using large-scale tests in natural terrain.

Schnee mit low-cost GPS Sensoren messen

Low-cost GPS-Sensoren sind eine vielversprechende und ökonomische Alternative zur manuellen Messung des Schneewasserequivalents. Erste Resultate vom Weissfluhjoch auf 2540 m ü.M. sind vielversprechend. Mit drei zusätzliche Stationen wird untersucht, ob diese Methode praxistauglich ist.

Snow avalanche flow regime transitions

The aim of this project is to understand how increased temperature and precipitations will affect avalanche flow behavior, in particular flow transitions, and assess consequences for hazard mapping. For this purpose, we use experimental data from Vallée de la Sionne test site and DEM modeling.

Larger and more frequent debris flows in future?

This project will combine field monitoring of debris flow sites, laboratory and field experiments, two-phase granular flow mechanics and numerical simulations to assess how debris flow mitigation must evolve in future.

Multi-hazard risk assessment framework

The goal is to develop a multi-hazard risk assessment framework which is able to deal with several conjoint or cascading hazards as they can be expected as consequence of climate change in high mountain regions.

Integrated risk and resources management

This project contributes to a better understanding of the social and institutional barriers of an integrated management as strategy to climate-change related problems in Alpine regions.

WebSnow

Integration of Webcam data for deriving Snow cover and snow depth from Sentinel-1, Sentinel-2 and Pléiades data

Determining the Insurance Value of Ecosystems

The project expands the scientific bases for insurance services of forests and defines their value from the population’s perspective. In this way we can enhance the awareness of human dependence on natural resources and foster their inclusion in political, economic and individual decision-making.

Snow instability in a changing climate

Less snow, less avalanches? We investigate the influence of climate change on avalanches by using climate projections to model future snow instability for selected representative sites in Switzerland.

SLFPro – the platform on snow and avalanches

SLFPro is the feedback and information platform for SLF observers and local safety authorities. It is used to enter and visualize data in the area of snow and avalanches.

Improving avalanche forecasting with snow cover models

How would it change your picture of the avalanche danger, if you could look deep into the snowpack at any time and anywhere? We use snow cover models to improve our knowledge on the state of the snowpack to ultimately improve avalanche forecasting.

Lawinendruck auf Hindernisse

Lawinen stellen in Bergregionen stets eine erhebliche Gefahr für Menschen und Infrastruktur dar. Wir erarbeiten ein grundlegendes physikalisches Verständnis der Lawinenaufprallkräfte, um Gestaltungsrichtlinien weiter zu entwickeln, damit Strukturen effizient und standhaft gebaut werden können.

Avalanche terrain maps

New maps show avalanche terrain and take into account avalanche release and runout.

Rockfall Experiments

The SLF has developed software capable of simulating rockfalls. The computer model is being continuously aligned more closely with reality by way of experiments, such as those recently conducted on Spitsbergen.

Snowpack stability

For the very first time, scientists have been able to causally link patterns of snowpack characteristic variations to certain weather scenarios. Their findings could pave the way for forecasts which not only specify the general avalanche danger level, but reflect local variations as well.

Model avalanche release

A recently developed model describes the principal factors contributing to the release of a slab avalanche.

Drones

The latest results prove it: snow depths can be captured efficiently and inexpensively in the mountains by using drones. This technology opens new doors in the field of snow research.

EconoMe

When planning to protect a specific section of road or a settlement against avalanches, a decision has to be taken on which of the options – barriers or a snow shed – is the most suitable means of defence. A variety of online tools are now available to facilitate an assessment of the risk posed by natural hazards, and to examine the effectiveness and economy of different protective measures.

Rock slope failure Piz Kesch

A recently published study shows that the occurrence of a major rock slope failure, such as the one that took place on Piz Kesch in February 2014, depends not only on the conditions prevailing at the time, but also on the long term interaction of geology and climate over millennia.

RAMMS::RISK

RAMMS::RISK berechnet und visualisiert die räumliche Verteilung von Risiken für Naturgefahren.

Satellite data

A feasibility study overseen by the SLF has demonstrated the ability of data captured in space to further improve avalanche forecasting. At present, however, the cost of implementation is too high.

Shear apparatus

In the laboratory, researchers are investigating the process which causes snow to fracture. They are endeavoring to establish whether acoustic signals could serve as an early warning.

Seismic avalanche detection

SLF is working on detecting avalanches with seismic sensors - as is usally done for earthquakes.

EPIC

Snow avalanche interaction with forests is evaluated in three mountains ranges of the world: the Andes (Chile), the Himalayas (Nepal) and the Alps (Switzerland). We aim at better integrating forest effects in existing avalanche dynamics models for risk analyses, as well as deducing adapted strategies for forest management in different mountain ecosystems.

Chilean copper mines

An avalanche simulation model is helping Chilean safety authorities to decide when to close a road that permits access to copper mines.

Rockfall nets

Thanks to a new SLF computer model, industry will be able to design rockfall nets more cost-effectively and efficiently in future.

Projekt Schneefräse

Für die Simulation der Vorgänge in einer Schneefräse, muss zum einen das Fliessverhalten von Schnee mathematisch beschrieben werden. Zum anderen muss die Computersimulation mit Messwerten aus realen Versuchen verglichen werden, um die Richtigkeit des Modells zu überprüfen.

Forests and avalanches

Trees are capable of slowing down and stopping avalanches before they can endanger settlements and their inhabitants. The SLF is investigating the complex interaction that takes place between forest structure, snow properties and the terrain.

Temperature in avalanches

Experiments with artificially triggered avalanches and a concrete mixer show the importance of the snow temperature for avalanche dynamics.

Prevent-Building

In collaboration with several engineering offices, the SLF has developed a software product for examining the cost-effectiveness of building protection measures.

Fracture propagation

Before a snow slab avalanche releases, a buried weak snowpack layer has to fracture (break) over a large area. For a long time now it has been known that slab avalanches only release on steep slopes, that is on slopes steeper than 30 degrees.

Climate risk analysis

The project develops a method to analyze and assess risks (and chances) related to climate change. The method is tested and applied to a regional case study in the Canton of Aargau. The method development and the assessment of climate risks are key elements of the Swiss national climate adaptation strategy.

REWARN

Warning and alarm systems are part of an integrated risk management approach to reduce the risk against natural hazard. Integrating these systems into an integrated risk management approach, requires to quantify their effectiveness.

Avalanche Release Areas

Thanks to a new model, the size and reach of avalanche starting zones can now be more accurately estimated. The relationship between terrain roughness and amount of deposited snow is the key.

Rock-shape

A key factor determining the trajectories of rockfalls is rock-shape. But which rock-shapes are the most dangerous? Using rockfall experiments with special motion sensors and a new rockfall model that can simulate real rock-shapes; we are beginning to answer these questions.

Snow Depth Mapping

Information on large scale snow depths is still mainly based on interpolated point measurements. New developments in sensor – and software technology for digital photogrammetry in the last two decades offer new possibilities to derive high resolution, digital surface models (DSM) even over snow covered high-alpine regions.

CapHaz-Net

CapHaz-Net is a unique collaboration project that brings together social scientists from various European countries. Funded by the European Community it reviews how institutions and people in Europe cope with and adapt to natural hazards.

CLISP

Climate change and its related impacts are strongly affecting land use and land use development. But what potential lies within spatial planning? How can we better adapt to climate change risks? Are our instruments sufficient? How can we improve our existing instruments?

Codelco's Andina copper mine

In collaboration with two Swiss engineering companies, the SLF has proposed mitigation measures against avalanches, debris flows and rockfalls in order to protect the access road to the Andina copper mine operated by Codelco. The proposal encompasses a combination of temporary and structural protective measures.

Solaranlagen

The idea of installing solar panels on snow supporting structures has been growing in popularity in recent years. When planning such solar power plants, it is essential that the functional integrity of the avalanche defence structure is not impaired. In conjunction with the Expert Commission on Avalanches and Rockfall (EKLS), the SLF has formulated a set of recommendations containing specifications and criteria to be considered for the installation of solar panels on avalanche barriers.

DEMalpine

We investigate the advantages and disadvantages of different remote sensing based technologies to generate such terrain models for high alpin regions.

High Resolution Radar

Obtaining a thorough understanding of the dynamics of snow avalanches is crucial for both the design of defensive structures and the drawing of hazard maps. Until now there has been no way of accurately tracking the dynamics of large avalanches at high spatial and temporal resolutions. Frequency Modulated Continuous Wave phased array radar will image the dense layer through the powder cloud at a Vallée de la Sionne test site.

Avalanche defence Sochi

The next Winter Olympic Games will be hosted by the Russian city of Sochi in 2014. The alpine skiing events are to be held in the Rosa Khutor resort. The SLF was commissioned by the Sochi 2014 Organising Committee to evaluate the planned avalanche mitigation measures.

Risk concept

Residents and visitors are likely to be exposed to avalanches, rockfalls, floods and landslides. For decades, safety experts have been seeking to prevent such natural hazards with civil engineering works, but the focus of their strategy is now shifting towards minimising risk.

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