Category Archives: Hazard news

Rockslide in Val Sterm, Graubünden

Rockslide on snow in Val Sterm (GR), Switzerland, on 15 March 2016.

At 6 PM on 15 March 2016, a 200’000 m3 rockslide occurred in the unoccupied valley Val Sterm near the village of Sedrun (GR) on 15 March 2016. Rocks fell from the East side of the North -South oriented valley and, after reaching the valley bottom, turned 90 degrees southwards and came down the snow covered valley on a runout travel distance estimated to about 1 km. Nobody were injured by the event but a water supply infrastructure was damaged.
Source: ANRSource: ANRSource: Ervin Monn Source: Ervin Monn Source: Ervin Monn Source: Ervin Monn

Large rockfall in Wolhusen

River damming by rockfall in Wohlusen (LU), Switzerland, on 11 January 2016.

At 3 AM on 11 January 2016, a 5’000 cubic meters rockfall fell from a 50 m height cliff in the village of Wolhusen in the Canton of Luzern, Switzerland. The rockfall fell into the Kleine Emme river, built a dam deflecting the river path. The cliff was described as highly hazardous in the hazard map. The neighborhood composed of residential and industrial buildings was flooded (with diesel pollution) and boulders were projected over a travel distance of 200-300 m causing damages to buildings. 20 people have to be evacuated, a main road as well as a train track had to be closed and 3 power supply installations were affected generating power failures. Nobody were injured by the event. Damage are estimated to over 1 million Swiss francs.

After the event, the cliff has been cleaned and secured. On the ground, 12’000 cubic meter of deposit material have been evacuated. Repair work including flood protection wall restoration last until early summer 2016.

Further similar rockfalls in the same site are expected and therefore the Canton of Luzern has started a global risk reduction project in this area for rockfall hazard and floods.

UAV video here (ZSO Emme).

Source: ZSO Emme

Source: Philipp Schmidli

Source: Philipp Schmidli

Source: Keystone / Urs Flüeler

Source: reader reporter

Sources: Neue Luzerner Zeitung (1), (2), (3) and (4); Neue Zürcher Zeitung (1), (2), (3) and (4).

Images from October 2016:

Wohlusen rockfall October 2016

Detail of the rockfall

Warning sign with hazard levels

Bad weather in Graubünden, July 2015

Two severe storms at one day interval have caused damages due to debris flow in Scuol (GR), lower Engadine, at the end of July .

During two days of high precipitations in Scuol, on 22 and 23 July 2015, several debris flow caused many infrastructures damages.

On 22 July 2015, three buildings in the Pradella hamlet near Scuol were damaged by a debris flow. People of two holiday camps, 100 children and 40 adults, were evacuated. Nobody was injured but the buildings damages are important.

A day after, about 200 mm rain in a short time were measured in the same area. An auto has been swept away by a debris flow in the Scuol village and its driver could escape at the last moment.

The S-Charl valley was isolated during more than one week by seven big debris flows and several little ones. About 100 people, in majority holidaymakers, were blocked in the S-Charl hamlet without power supply during few days. Until the swiss army built a provisional emergency bridge to open the valley access, the only way to access the S-Charl valley was by helicopter.

Overall damages –roads infrastructures, buildings, drinking water supply, power supply and other- are estimated to one million Swiss Francs and the debris flow volume is estimated to 100’00 cubic meters.

Sources: NZZ (1, 2, 3 and 4)

Images sources: J. Voumard – Risk Group

Military bridge and debris flow in S-Charl valley

Lake generated by debris flow in S-Charf valley

Debris flow in Scuol

Damaged house in Pradela hamlet

Bad weather in Western Switzerland, May 2015

Bad weather caused damages and evacuations in Western Switzerland in early May due to floods, debris flow and landlsides.

Strong precipitations occurred on Western Switzerland in the beginning of May 2015, especially on May 1st. Over 100 mm of rain fell in about 24 hours in some places in Western Switzerland, with a maximum of 130 mm at La Dôle, Canton of Vaud. Those heavy rains caused different damages as debris flow, floods and landslides.

Several roads and railway have been closed, preventively or due to tracks obstructions in the Alps, the Jura mountains and in the Swiss Plateau. Two landslides have disrupted two main railway tracks, causing high traffic disturbances due to deviations and affecting the railway traffic during more than one week.

In the village of St-Gingolph in the Canton of Valais, the Morge river -which is the border between Switzerland and France along the lake Léman- overflowed two restaurants with debris flows. Their groundfloor levels have been totally destroyed.

In the town of Monthey, Canton of Valais, about 300 residents along the Viège river have been evacuated during the night because of the high risk of floods.

The Arve river -which flows through the Chamonix Valley in the French Alps- has reached a flow rate record with 903 m3/s compared to its standard flow of 77 m3/s at its mouth into the Rhône river in Geneva on 2nd May. Several bridges in the town had to be closed, affecting the urban traffic of the second biggest town of Switzerland.

North-east of the Western Switzerland, the lakes of Neuchâtel (Canton of Neuchâtel), Biel (Canton of Bern) and Morat (Canton of Fribourg), overflowed because of the high flow rate of the Aare river. The maximum height of water level has been reached about 8 days after the first heavy rain with a water level increase of 1 meter. A lot of wood has been carried by the rivers to the shores of the lakes.

The damages are only material, no injuries were identified. Financial and temporal damages consequences are high for the two destroyed restaurants. The return to normality for river flows and water levels of the lakes took several weeks.

Sources: Federal Office for the Environment, Tribune de Genève, Le Temps

Images sources: J. Voumard – Risk Group

Grande_Eau_River Wood_on_Lake_Leman St-Gingolph_Restaurants St-Gingolph Restaurant_in_St-Gingolph Morge_River_in_St-Gingoph Media_in_Lutry Landslide_Flamatt Lake-of-Neuchatel Island_Lake-of-Neuchatel

Mudslide crashed into a small building in the Swiss Alps

A three-storey appartment building was destroyed by a landslide on November 16th 2014 in the canton of Ticino, Switzerland. Two women were killed.

At 2:30 pm, a wall -weakened by the heavy rainfalls- located 50m away and above the building broke, releasing 500 m3 to 1’000 m3 of muddy material in the Davesco-Soragno village, near of Lugano. Hundred rescuers accompagnied by sniffer dogs worked during the night in the rubble to find the victims. Besides two fatalities, one man was seriously injured, three persons were slightly injured and one person kept uninjured.

Strong rain precipitations occurred since at least ten days before the event on the area of Lugano. This landslide occurred 11km away from the previous disaster where two persons were killed 11 days ago.

Sources: bbc, rts, 24heures and 20minuten.

Davesco-Soragno - Keystone/Gabriele Putzu Keystone/Gabriele Putzu

Davesco-Soragno 2 - Keystone/Gabriele Putzu Keystone/Gabriele Putzu

Davesco-Soragno 3 - Keystone/Gabriele Putzu Keystone/Gabriele Putzu

Davesco-Soragno, event location / Copyright: swisstopo Copyrights Swisstopo


Landslide destroy a house in Swiss Alps

A two-storey house located in a large wooded area was destroyed by a landslide on November 5th 2014 in the canton of Ticino. The two occupants, a mother and her three years old daughter, were killed.

Shortly after 6:00 pm, a 1’000 m3 landslide composed of mud, trees and rock masses flew over 150 meters and hit a house of the Bombinasco village, 10km West of Lugano. Eighty people (rescuers, firefighters and sniffer dogs) worked all the night in the rubble and found the two victims at 4:30 am the following day.

Strong rain precipitations occurred before and during the event on the area of Lugano. A road close to the drama location was buried by a landslide few hours before.

Sources: 24heures, 20minutes and blick.

 Rescue Media Rescue Media

Keystone/Gabriele Putzu Keystone/Gabriele Putzu

Event location / Copyright Swisstopo Copyrights Swisstopo


Train derailed due to a landslide in Swiss Alps

A train of the Rhaetian Railway derailed into a ravine after hitting a landslide felt on the track on August 13th 2014. Eleven persons were injured, five of them seriously. One person died in the hospital ten days after the event. About two hundred persons were in the train.

Almost 180 rescuers with eight ambulances and four helicopters were involved in the rescue operations. The landslide occurred near the village of Tiefencastel between Chur and St-Moritz in the canton of Grisons. A 15 m long section of the railway track was buried with up to 3 m of material.

When the train hit the landslide, three passenger cars derailed. The first one, placed behind the locomotive, felt down about twenty meters into a ravine with a 45° slope. It was stopped during its fall by trees. The second passenger car stayed on equilibrium over the edge with the help of passengers who went to the back of the car to avoid its fall.

Weather conditions seem to have contributed to this event. It rained between 50 and 60 liter per square meter in 12 hours. This represents half of the usual monthly rain precipitations in the area.

Sources: bbc, 24heures, 20minutes.

Keystone Keystone

AFP Michael Buholzer AFP / Michael Buholzer


(c) Swisstopo Copyright Swisstopo


Badakhshan landslides, Afghanistan

The village of Abi Barik (Badakhshan Province, North East Afghanistan) was destroyed by two consecutives landslides on May 2 2014 (DailyMail). About 1000 houses were affected and 300 of them were buried under 60 meters of debris (AlJazeera). Fatalities number is unknown but some sources reported 350 killed people and 2500 missing persons (LeMonde).

While the villagers attempted to save some goods and cattle after the first little landslide, a second massive landslide occurred, covering many people (LeFigaro). Landslides trigger is probably the very heavy rain that occurred a week before the events (TheWallStreetJournal).

Wakil Kohsar/AFP/Getty Images
Wakil Kohsar/AFP/Getty Images

Massive landslide in the United States – Oso (Washington State)

The area named “Steelhead Haven” was engulfed by a major landslide on March 22, 2014, in Oso, Washington, United States (SeattleTimes). 41 fatalities (Snohomish County Sheriff’s Office) and 2 missed persons were identified (Snohomish County Sheriff’s Office). Mud masses collapsed from an unstable hill and covered an area of about 2.5 km2 , destroying 49 houses and other structures (SeattleTimes). Suspected cause is soil saturation because of heavy rainfall (WashingtonPost).

For more information about the geology of the landslide, please see the article in the ScienceMag and from the USGS site. To have a look at the landslide area, see the ArcGis 3D model and the “before versus after” graphic.


Source: Ted. S WARREN / Associated Press

Southeast and Central Europe floods

Important floods occurred in Central and Southeast Europe in middle May 2014, affecting four countries (Serbia, Bosnia and Herzegovina, Croatia and Romania) and causing at least 62 fatalities and more than one billion euros damages (StiriTV). Over 2000 landslides were induced by the floods across the Balkan area (Independent). Serbia was the most affected region follow-up by Bosnia and Herzegovina (respectively 33 [b92] and 24 fatalities [AlJazeera]). Those events are the heaviest rains and floods recorded in the past 120 years in these two countries, with more than 105 mm daily rain recorded in several major towns like Belgrad (Independent).

One of the main concerns of the authorities after the floods peak is that it remains more than 100’000 land mines across Bosnia and Herzegovin from the Bosnian War (1992-1995). Many of those have been dislodged by the extreme rains, floods and landslides and are now out of control (Independent, Reuters and AlJazeera) .


AP/Amel Emric
AP/Amel Emric