Subproject 5: Dissemination on risk assessment
Vulnerability and
risk seminar November 2005
The 17th of November 2005 a seminar on risk and
vulnerability analysis was arranged at NGI. The speakers and
participants were sought to represent the different steps in risk
analysis, see Figure 1
Figure 1: Stakeholder in risk assessment steps
The aims of the seminar were to
-
Form an arena where
specialists, authorities, engineers and researchers can openly
exchange experience and ideas about risk assessment
-
Get to know each
others’ needs and problems
-
Increase the
understanding for vulnerability and risk analyses
The seminar consisted of five main parts:
-
Scope of analysis
-
Hazard assessment
-
Vulnerability
assessment and consequence analysis
-
Risk estimation
-
Risk assessment and
mitigation
There were speakers from ICG (NGI and NORSAR),
Directorate for Civil Protection and Emergency Planning, County
Governor of Sør Trøndelag, County geologist of Møre and Romsdal,
National Office of Building Technology and Administration, Scandpower,
Standards Norway, Middle East Technical University and Norwegian Water
Resources and Energy Directorate
Below you find ppt.-presentations given in the different parts of the
seminar. Clicking the blue links opens the documents.
Part I: Scope of risk analysis
Figure 2: Example that
several actors are involved in landslide risk management
Introduction by Suzanne Lacasse (NGI)
Risk terminology by Unni Eidsvig (NGI)
Risk and
vulnerability analyses by Nils Ivar Larsen (DSB)
Expectations from County governor by Svein Horn Buaas
Mountain slides and tsunamis in Møre og Romsdal by Einar Anda (County
geologist)
Risk acceptance by Kari-Anne Pape Simenstad (BE)
Part II: Hazard assessment
Figure 3: Qualitative hazard map
Quick clay risk by
Odd Gregersen (NGI)
Landslide hazard by
Karstein Lied (NGI)
Hotspots
by Farrokh Nadim (NGI)
Part III:
Vulnerability assessment and consequence analysis
Figure 4: Population
vulnerability for 1980-1990.
Some highlights from landslide risk management conference in Vancouver
by Unni Eidsvig
Vulnerability in relation to risk management by Sebnem Düzgün (Middle
East Technical University)
Part IV: Risk estimation:
Figure 5: Localisation
of the Ormen Lange Gas Field
Risk
estimation for Ormen Lange by Jan Lund (Scandpower)
Part V: Risk assessment and mitigation:
Figure 6: Risk
acceptability
f-N curves, social aspects and risk acceptability by Sebnem Düzgün
Mitigation
against natural disasters by Steinar Schanche (NVE)
Environmental risk by Gijs Breedveld (NGI)
Åknes Risk
workshop October 2007
Figure 1 A workshop
was held at NGI October to discuss and assess the risk associated with
the Åknes rock slope.
Åknes is a rock
slope over a fjord arm on the west coast of Norway. The area is
characterised by frequent rockslides, usually with volumes between
0.5 and 5 millions m3. Massive slides have occurred
in the region, e.g. the Loen and Tafjord disasters. Bathymetric
surveys of the fjord bottom deposits show that numerous and gigantic
rockslides have occurred many thousands of years ago. The
Åknes/Tafjord project (www.aknes-tafjord.no)
includes site investigations, monitoring, and an early warning system
for the potentially unstable rock slopes at Åknes in Stranda County
and at Hegguraksla in Norddal County. The project
also includes a regional susceptibility and hazard analysis for the
inner Storfjord region, which includes Tafjord, Norddalsfjord,
Sunnylvsfjord and Geirangerfjord.
The potential
disaster associated with a rockslide and tsunami involves many
parties, with differing opinions and perceptions. As part of
the on-going hazard and risk assessment and validation of the early
warning system, event trees were prepared by pooling the opinion of
engineers, scientists and stakeholders. The objective was to
- Bring in all
stakeholders into the discussion of hazard and risk at Åknes
- Reach a consensus
on the hazard and risk associated with a rockslide triggered-tsunami
- Discuss and
evaluate mitigation measures
- Experiment with
ETA as communication tool
The following event
trees were constructed during the three-day meeting:
- rockslide due to
seismic trigger
- rockslide due to
high pore pressure trigger
- rockslide due to
weathering and creep trigger
- tsunami wave
against Hellesylt
- consequences of
tsunami
- optimum
observations for early warning
The participant list
for the results shown below included the following representatives:
