Global Mountain Sustainability Forum, Sexten/Sesto, 05 October 2020

Dealing with risks in the mountains. Yesterday. Today. Tomorrow? Jakob Rhyner

The hazards

Snow avalanche: Davos

Tottent (unknown location)

Deep-seated landslide: Brienz-Brinzauls Rock avalanche / mud flow: Bondo

Rockfall : Gotthard (highway)

Green energy generation: Zervreila (Switzerland)

A village disappeared Source: Kraftwerke Zervreila

Vals-Zervreila (1911).

Photo: Rudolf Zinggeler

Disaster Risk: 1. Landslide into lake, spill over  around 25 fatalities 2. Damage to dam, rapid discharge  around 1‘500 fatalities

cf. From Gefährdungsanalyse Kanton Graubünden, (public)

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Dealing with with risks in the 13th century:

the Schöllenen bridge

Picture by Roland Zumbühl

Teufelsbrücke

Schöllenen gorge The first user…

Source: Denkmalpflege Schweiz

Teufelsstein

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Early efforts to reduce avalanche risks (14th century) Picture by Roland ZumbĂźhl

Bannwald Andermatt 6

17th/18 century - religious connotations J. L Bleuler (1792-1850 )

Picture by Roland ZumbĂźhl

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Traversing the Alps in the 18th century Stellenweise musste auch durch eine kleine Lawine erst ein Hohlweg gegraben oder eine grössere im Bogen umfahren werden. In some places, one had first to dig hollow path through a small avalanche or drive around a larger one. Ernst Haeckel Als die gefährlichsten Stellen des Herabstieges, das durch die vielen Lawinenstürze berüchtigte wilde und düstere Val Tremola, wo im vorigen Jahre eine Lawine einen Postschlittenzug mit 45 Menschen in den Tiefen des Abgrundes begraben hatte, erst vorüber waren, ging es nun vollends mit lustiger Geschwindigkeit weiter.

When the most dangerous parts of the descent, the wild and gloomy Val Tremola, notorious for its many avalanche chutes, where last year an avalanche had buried a post sleigh with 45 people in the depths of the abyss, had only just passed, the journey continued at a fun speed.

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19th century - first scientific-technical attempts Johann Coaz Vallascia TI

Johan Coaz (1822-1918)

Dry stone walls • Effective small/medium avalanches with average snow height • With their decay the are turning into a rockfall risk! • Partly protected as cultural heritage

Source: hochparterre 9

20th century – systematic hazard and risk research

WSL Institute for Snow and Avalanche Research SLF, Davos Founded 1936

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Modern avalanche defense measures

Männlichen

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Hazard maps – supported by avalanche flow modelling  Local experience combined with expert knowledge by engineers  Since around 15 years: strong support by GIS-based modelling RAMMS - Rapid Mass Movement Simulation P. Bartelt et al. Swiss Snow and Avalanche Research Institute (SLF), Davos • snow avalanche • mud flow, • rock fall / avalanche https://www.slf.ch/en/services-and-products/ramms-rapid-massmovement-simulation.html

permanent post-event verification!

European cooperation – the ToDos LACRUX.COM Klettermagazin, 25 December 2019 Wir stehen zu dritt auf der Dreiländerspitze in der Silvretta. Einer von uns in Tirol, einer in Vorarlberg, einer in Graubünden. Wir befinden uns in zwei verschiedenen Staaten in drei verschiedenen Verwaltungszonen. Je nachdem in welche Richtung wir abfahren, gilt eine andere Lawinenprognose. Das SLF in der Schweiz spricht von einer Gefahrenstufe Eins, der Lawinenwarndienst Vorarlberg von einem Zweier und die Tiroler geben gar einen Dreier aus. The three of us are standing on the three-country peak in the Silvretta. One of us in Tyrol, one in Vorarlberg, one in Graubünden. We are in two different states in three different administrative zones. Depending on the direction in which we descend, a different avalanche forecast applies. The SLF in Switzerland speaks of a danger level one, the avalanche warning service Vorarlberg of a two and the Tyroleans even issue a three.

Avalanche fatalities during the last decades (Switzerland)

Source: SLF Davos

https://www.slf.ch/en/avalanches/destructive-avalanches-and-avalanche-accidents/long-term-statistics.html

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When and how did progress occur? Floods 1800

1820

1840

1860

1880

1900

1920

1940

1960

1980

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1800

1800

1820

1840

1860

2000

3

1880

1900

1

1920

1940

2

1960

1980

3

4

2000

Avalanches

2005

4

1.

River and forest legislation

1.

First avalanche defence structures

2.

1880: River management

2.

Foundation SLF Davos

3.

Systematic hazard mapping

3.

4.

Warning systems (GIN)

1951: Massive defence programme (1.5 Bill CHF so far!) und upgrade warning systems, end 50ies : 1st model hazard maps

4.

Comprehensive early warning system IMIS-IFKIS

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Integrated Risk Management (IRM) Defense barriers

Deflection dams

Hazard maps Warning Closure Evacuation Choice of measure combination adapted to situation ďƒ Integrated Risk Management

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Conceptualization of IRM Recovery

Reconstruction Insurance Mitigation of indirect consequences

Prevention Land use planning Technical measures Biological measures

Risk cycle

Intervention Forecast and Warning Evacuation Closure

Risk

i : object j : scenario

Ri,j = pj . Pi,j . Ai . Vi,j . i,j

Probability of scenario

Exposition

Damage Potential

Risk Aversion Vulnerability 17

Marginal cost approach

Marginal costs

willingness to pay !

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Protection targets Risk Category

Category 1

100 % voluntary (High risk sports)

Category 2

high degree of voluntariness

Category 3

low degree of voluntariness

Category 3

100 % involuntary (settlement areas)

Individual Risk

Collective Risk

Material damage

Max. Value of risks of death per year

Max. marginal costs per 1 saved life per year (Mio. CHF)

Max. ratio of cost of measures and cost of damage

10-2 - 10-3

1-2

1

10-3 - 2·10-4

2-5

1

2·10-4

3·10-5

-

5 - 10

3

3·10-5 - 4·10-6

10 - 20

4

Source: PLANAT Strategie Naturgefahren Schweiz Synthesebericht 2003

Protection targets – policy implemenation (Canton Bern)

1.1 Explanation of the risk strategy of the Canton of Bern of 2005In the risk strategy of the Canton of Berne, the government on August 24, 2005 adopted: -

The individual risk of death due to gravitational natural hazard processes must not increase than 10-5 to 10-6 per year.

-

If the prevention of a death by protective measures is less than CHF 5 million the measure should be implemented.

Looking into the future It’s difficult to make predictions, especially about the future (assigned to a couple of famous people, including Niels Bohr)

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Connectedness - influence from to the mountain side and from the lowlands Energy

Tourism

Source: NOAA

Source: NOAA

Hazard risk, rising snow line

Unsteady water supply due to melting glaciers

Dynamics of tourism market(s)

„Greening“ energy market

Safe, green and attractive summer tourism

Supply of peak energy, pump storage 22

Climate impacts – overload from „steady weather“

Source: NOAA

Rossby wave

Source: südostschweiz

Forcella / Arvigo, 05 March 2014 (S. Schneiderbauer et al. Beyond the Expected - Dealing with Cases of Overload and the Residual Risk of Natural Hazards in the Alpine Region) 23

Innovative summer tourism - dealing with melting

Triftgletscher 1948 and 2006. Source:‚Die Alpen‘ Issue 07/2014.

2009

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Good risk management is sustainable Good sustainability management is risky

Thank you for your attention! 25

HunsrĂźck-Geierlay. Source: mosel 2.0

Kontakt Office of the Bonner Allianz für Nachhaltigkeitsforschung Prof. Dr. Jakob Rhyner | Wiss. Director | 0228 73 4973 |rhyner@uni-bonn.de Sandra Gilgan | Geschäftsführerin | 0228 73 60594 | s.gilgan@uni-bonn.de Una Kliemann | Projektmanagerin | 0228 73 60615 | u.kliemann@uni-bonn.de www.bonn-alliance.uni-bonn.de