Business on the little Nesthorn Ob Blatten VS threatened

Up to three million cubic meters of rock mass are “acutely at risk of falling” on the small Nesthorn. The authorities had the village evacuated the village.

What happened in Blatten (VS)?

Above the village in the Lötschental, a landslide threatens to make a huge extent. According to the authorities, rock masses with a volume between one and three million cubic meters are “acute at risk of falling”. This corresponds to up to 200,000 truck loads.

Therefore, the village was completely evacuated on Monday morning. For a good third of the village, an evacuation was ordered on Saturday.

There have been striking shifts on the flank of the little Nesthorn in the past few days. The rock masses move several meters a day towards the birch glacier. And they do that faster and faster – now 30 meters a day.

There is also a lot of movement on the little Nesthorn in the vertical: « The whole mountain has sagged 8 meters, » said Alban Brigger from the Office for Natural Rounds of the Canton of Valais on Monday.

If this mass falls on the glacier in a thrust, this could lead to a quick mening and destroy large parts of the village. Therefore, the evacuation personal seeds has been expanded. Only the two hamlets and Weizenried are still considered safe because they lie on the opposite slope.

How could this come about?

Rocks and millions are not unusual on the small Nesthorn and the bay glacier underneath. But why there is suddenly such quick and strong movements was not clear until Monday evening.

One possible reason could be the permafrost: if it melts faster due to climate change, the rock in the mountains can detach faster. In the critical area, however, the melting of snow has just started. The change could therefore simply be the consequence of a « normal erosion process in the mountains », it is said by the Valais authorities.

What scenarios do the authorities expect?

The authorities monitor the situation on site with GPS measurements and exploration flights across the affected area and radar devices. Alban Briggen said that you will expect new drops and slides in the next few hours.

A scenario, which is advantageous in view of the location, would be several larger pumps that come to the lower area of ​​the birch glacier instead of a single gigantic rock slip that thunder down into the valley.

How big is the danger of such events in Switzerland?

As the Federal Office for the Environment (BAFU) writes, Switzerland is regularly affected by natural hazards. According to the storm damage database of the Federal Research Center for Forest, Snow and Landscape (WSL), Switzerland recorded around 32.8 documented severe weather events with property damage between 2002 and 2022 per year.

Between 1972 and 2001, only 19.3 events per year were registered. This database only includes events such as floods, murgeon lengths, slides and rock falls. Consequential damage to avalanches, snow pressure, earthquake, lightning stroke, hail, storm and dryness are not taken into account in the evaluation.

While the number of damage events has increased, there are fewer fatalities due to natural events. According to a study, 1023 people died in natural events between 1946 and 2017 – including avalanche victims.

On average, the annual damage costs are CHF 300 million due to natural events.

How has the risk changed?

Climate change has led to an increased risk. According to the Federal Office for the Environment, natural events in Switzerland become more frequent and more intensive. They could also occur more in previously spared areas and in unusual seasons.

Above all, however, the damage potential has increased. This as a result of the increase in population, the expansion of the settlement area into endangered regions and the increase in value of infrastructures and real estate.

How much settlement space is natural hazards affected?

A large part of the Swiss population already lives in areas where natural hazards can occur. A fifth of the population is now exposed to the risk of floods. Around 7 percent live in areas that can be affected by avalanches, slides, rock falls or rockfall. A third of all jobs – almost 2 million – are also in these areas.

What do the authorities do to protect the population?

Protection against natural hazards in Switzerland is a common task of the federal government, cantons and communities. Private also have certain duties, for example as a homeowner.

Switzerland has been relating to “integral risk management” for almost 25 years. Damage caused by natural hazards should be avoided as far as possible. If they still appear, they should be kept as low as possible.

For this, the federal government relies on early detection, hazard cards and risk -based spatial planning. If possible, there should be no new buildings in danger areas, existing buildings are protected with measures.

In the event of the event, the authorities are generally responsible on site. You have to prepare for possible scenarios and be able to offer the necessary resources. This includes emergency accommodations and sufficient emergency care.

I live in a potentially endangered area. Do I have to adjust to an evacuation now?

Not directly. In most risk areas, the municipalities and cantons have taken sufficient measures to recognize risks at an early stage. The Federal Office for Population Protection provides information via alert.swiss continuously about unusual locations and developments.

Currently, the federal government has only pronounced warnings in Blatten (VS) and Brienz (GR); There is also a landslide in Ticino. However, since a situation can tighten very quickly, the federal government recommends being prepared for emergencies.

How do you prepare for it?

It is best to start with an emergency plan – for example with contact information from relatives, relevant meeting points and checklists for possible evacuation.

Ideally, you determine an emergency accommodation in advance and plan how to best achieve it. In addition, there is a piece of food that includes copies of the most important personal documents, a small pharmacy and a battery -operated radio. Templates and checklists for emergency plans the federal government provides.