AUSTRIAN SERVICE FOR TORRENT AND AVALANCHE CONTROL · Avalanche Control Watershed Management Rock...
Transcript of AUSTRIAN SERVICE FOR TORRENT AND AVALANCHE CONTROL · Avalanche Control Watershed Management Rock...
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AUSTRIAN SERVICE FOR TORRENT ANDAVALANCHE CONTROL
Thomas Fink
Federal Ministry – Republic of Austria, Sustainability and Tourism
Directorate III/5 – Torrent and Avalanche Control and Protection Forest Policy
18th June 2019
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CHARACTERISTICS / BOUNDARY CONDITIONS
• Austria: 2/3 alpine; only 37 % available for permanent settlement (especially
valleys and low land regions)
• pot. high precipitation (altitude)
Präsentationstitel 2Typical alpine valley
Amount of the preciptitation mm/a
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Natural risks in Austria
• about 400.000 objects are endangered from natural risks
• Death risk of some natural risks in Austria:
− Avalanches: 2,10 x 10-4 (~ 30 deaths/y) (espescially while skiing in unprotected areas)
− Lightning strike: 2,00 x 10-6
− Flood: 5,00 x 10-7
• Economic deficits in case of weather extremes in the last
20 years ~ 9.5 Mrd EUR (detected of Munich re-insurance
company)
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ALPINE NATURAL HAZARDS IN AUSTRIA - FACTS AND FIGURES
• Austria in general is exposed to heavy precipitation, floods, debris flow,
thunderstorms, hail and storm; snow avalanches in winter season
• 100.000 km of rivers and creeks and about 9.000 lakes are known
• 70% of total area is part of torrent and snow avalanche catchment areas
• 12.000 torrent catchments and 7.000 well-known snow avalanche paths are
documented
• Landslides and rock-fall potential in steep slopes depending on the geologic
situation
• Austrian Service for Torrent and Avalanche Control (WLV) was founded in 1884 as
a department of the k & k (imperial) Ministry of Agriculture (today Ministry of
Agriculture, Forestry, Environment and Water Management in Vienna)
• Torrents and avalanches are federal tasks according to Art. 10 of the Austrian
constitution4
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Disaster Cycle
• The goal of all measures is the reduction of risks and an increase of the security
against natural hazards
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The need of protection in alpine regions is constantly increasing.
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torrent control avalanche control rock fall control landslide control
We differ four „types of disasters“
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Planning prevention measures
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Using modern construction programs and presentation systems
Using hydrological detail analysis
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Structural Measures
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Structural measures –torrents
In torrential catchment areas
dams are built to stabilise the
beds of torrents against depth
erosion and to retain
sediments and woody debris.
Furthermore, dams to “dose”
flood discharge and sediment
transport as well as to “break”
the force of landslides are
used.
In densely settled areas it may
sometimes be necessary to
develop the discharge section
(regulation) or stabilise banks9
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Structural measures –avalanches
Snowpack-stabilising
structures are built using
steel, wood or steel nets
(wires).
In the runout zone of
avalanches deflecting dams
and catchment basins force
flowing avalanches to
deposit outside the
threatened residential area.
To protect highways and ski
areas also temporarily
effective techniques for the
artificial (targeted)
triggering of avalanches are
applied.10
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Structural measures - erosion
The protection against rockfall is provided
by means of steel nets which catch stones
in the process of falling. Catching dams
are built to ensure the safe deposit of
rockfalls.
Slides occur frequently in connection with
the escaping of water from a slope;
therefore the drainage of the sliding
block is one of the most efficient
techniques of slide stabilisation.
Furthermore, technical protection
structures like anchors, arrays of posts or
barriers are used to give slopes the
necessary stability.
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Structural measures –forests
Forests are the best possible kind of
vegetation to reduce runoff- and erosion
processes, for rock-fall protection and
protection against avalanches.
20% of the Austrian forests are so called
„protection forests“, that means: forests,
which protects against several risks. Austria
has approximately 0,1 ha protection forest per
habitant.
Frequent problems in protection forest
management are overaged forests, missing
regeneration (because of too high poulations
of hoofed game as deer and chamois), poor
assesibality, unfavorable tree combination and
poor vitality in case of the high sea level12
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Structural measures –forests
• For the management of protection
forests some specific forest
techniques, like the transverse
felling of trees and cutting high,
were developed (increasing the
roughness of the surface).
• Land use management measures:
Technical support measures for
immediate effects of protection.In
their shelter – silvicultural measures
for a long-term realisation of a
stabile protection forest. Long
project periods (15 – 30 years), long
regeneration periods.
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Land use management measures - examples
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Example afforestation “Schmittenbach” (Zell am See, Salzburg), uplifting of the timer-line
1887
2007
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FOREST DEVELOPMENT PLAN – www.waldentwicklungsplan.at
OSWI: BASIS = WEP S3 UND (S2)
Maßstab: 1:50.000Revision: ca. alle 10 Jahre
WEP App
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Land use management measures - examples
Example Integrated Project “Protection forestHallstatt“ (Hallstatt, Oberösterreich)
combination of avalanche-and rockfall measures withsilvicultural measures
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Land use management measures - examples
Example FWP “Hochtannberg“ (Schröcken, VBG)
combination of avalanche andsilvicultural measures(reafforestation and forestrestoration)
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Land use management measures – cost effect
Für einen Zeitraum von 10 Jahren ist zur gesamten Schutzwaldsanierung in Österreich die Schutzwaldmilliarde erforderlich !(Schätzungen aus den Landes-Schutzwaldkonzepten)
Der derzeitige Deckungsbeitrag aus öffentlichen Mitteln liegt bei rund 17 %
Costs of the protection against avalanches per ha
about € ~ 600.000
10-timesof the total costs for
restoring protection forests
or 100-times of the costs to receive the positive
effects of protection forests
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Investments in Austrian’s natural hazard prevention
54%
14%
11%
17%
4%
Expenses for Categories of Measures
Torrent Control
Avalanche Control
WatershedManagement
Rock fall, LandslideControl
Planning
Every year in
Austria approx.
€ 200 Mio. of
federal subsidies
are invested for
preventive
measures
including also
maintenance.
Torrent and
avalanche control
~ € 80 Mio, Water
Management and
Flood Protection ~
€ 120 Mio
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Alpine Hazards and Climate Change – heavy preciptiation
Alpine Naturgefahren und Klimawandel 20
1st August 2018Pettneu am Arlberg
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• Event Schnannerbach / Pettneu a. A. / TIROL
• 1st Aug. 2018 110.000 m³ solids
• catchment area: 6,58 km²
• av. slope: 18° (~ 33 %)
• max. elevation: 2.887 m.a.s.l.
• min. elevation: 1217 m.a.s.l.
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1992: slot barrier
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1992: slot barrier2014: adaption of slots
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SedimentsDesign event (HQ150): 40.000 m³
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SedimentsDesign event (HQ150): 40.000 m³1st August 2018: 110.000 m³
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SedimentsDesign event (HQ150): 40.000 m³1st August 2018: 110.000 m³80.000 m³ behind slot barrier
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SedimentsDesign event (HQ150): 40.000 m³1st August 2018: 110.000 m³80.000 m³ behind slot barrier10.000 m³ in channel
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SedimentsDesign event (HQ150): 40.000 m³1st August 2018: 110.000 m³80.000 m³ behind slot barrier10.000 m³ in channel
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SedimentsDesign event (HQ150): 40.000 m³1st August 2018: 110.000 m³80.000 m³ behind slot barrier10.000 m³ in channel20.000 m³ in preflooder
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1st August 2018: 110.000 m³Only few damages, no casualtiesthanks to a functional protection structure
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ThoughtsWhat happens if second event hits the Schnannerbach within days?
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Alpine Naturgefahren und Klimawandel 32
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Alpine Hazards and Climate Change – thawing permafrost
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Alpine Hazards and Climate Change – thawing permafrost
Alpine Naturgefahren und Klimawandel 33
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Alpine Naturgefahren und Klimawandel 34
Alpine Hazards and Climate Change – thawing permafrost
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Alpine Naturgefahren und Klimawandel 35
Alpine Hazards and Climate Change – thawing permafrost
ObersulzbachThawing permafrost SattelkarCombe: 2.130 – 2.730 m ü.A.Debris cone: 1.610 – 1.920 m ü.A.
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Alpine Naturgefahren und Klimawandel 36
Alpine Hazards and Climate Change – thawing permafrost
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Alpine Naturgefahren und Klimawandel 37
Alpine Hazards and Climate Change – thawing permafrost
ObersulzbachThawing permafrost SattelkarCombe: 2.130 – 2.730 m ü.A.Debris cone: 1.610 – 1.920 m ü.A.
Scenario 1: annual bedload input35.000 – 70.000 m³
Scenario 2: sudden discharge: up to 600.000 m³
Estimated transport capacity ofObersulzbach during flood event: 100.000 m³ ?
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Alpine Naturgefahren und Klimawandel 38
Alpine Hazards and Climate Change – thawing permafrost
Ofenkar Mitterkar Steinkar
Sattelkar
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Alpine Hazards and Climate Change – protection forest
Alpine Naturgefahren und Klimawandel 39
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Alpine Hazards and Climate Change – protection forest
• HIER weitermachen mit Schutzwald Sturmkatastrophe
Alpine Naturgefahren und Klimawandel 40
Kals/Osttirol: windfall 29./30.10.2018
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Alpine Hazards and Climate Change – protection forest
Alpine Naturgefahren und Klimawandel 41
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Alpine Hazards and Climate Change – forest fire
Alpine Naturgefahren und Klimawandel 42
EchernwandGem. Ebensee: 21.08.2018
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Alpine Hazards and Climate Change – forest fire
Alpine Naturgefahren und Klimawandel 43
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Alpine Hazards and Climate Change – forest fire
Alpine Naturgefahren und Klimawandel 44
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Alpine Naturgefahren – facing challenges
Alpine Naturgefahren und Klimawandel 45
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Alpine Naturgefahren – facing challenges
Alpine Naturgefahren und Klimawandel 46
Obertauern 1952-1954
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Alpine Naturgefahren – facing challenges
Alpine Naturgefahren und Klimawandel 47
Obertauern 2017
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Alpine Naturgefahren – facing challengesecological aspectsÖkologische Aspekte
Alpine Naturgefahren und Klimawandel 48
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THANKS FOR YOUR
ATTENTION.
Thomas Fink
Federal Ministry – Republic of Austria, Sustainability and Tourism
Directorate III/5 – Torrent and Avalanche Control and Protection Forest Policy
18th June 2019