Transcript Assessment of global landslide hazard hotspots

Internasjonalt
forskningssamarbeid om skred;
SafeLand – et nytt stort integrert
forskningsprosjekt i EUs 7.
Rammeprogram
Skred og vassdragsdagene, Tromsø,
9 juni 2009
Bjørn Kalsnes
Nestleder International Centre for Geohazards
INTERNATIONAL CENTRE for GEOHAZARDS
A Norwegian Centre of Excellence established in
2003 by the Reseach Council of Norway
10 years duration
Budget : ~ NOK 20 – 25 mill. / year
(including in-kind contribution of partners,
Contribution from Research Council of Norway = NOK 12 mill. / year)
HOST ORGANISATION
Norwegian Geotechnical Institute (NGI)
PARTNERS
University of Oslo (UiO)
NTNU
Geological Survey of Norway (NGU)
ICG’s current research topics
Proj. No.
Title
2
3
4
5
6
Risk and vulnerability analysis for geohazards
Earthquake hazard, risk and loss
Stability of rock slopes
Geomechanical modelling
Offshore geohazards
7
Slope instability assessment and hazard zonation
10
Tsunami modelling
12
Remote sensing, monitoring and early warning systems
Theme 1
Geophysics for geohazards
Theme 4
Prevention and Mitigation
Landslide risk research project - SafeLand
• EC Call 2008 – Prediction of triggering and risk assessment
for landslides (in a global change perspective)
• 25 partners from 12 countries
• Coordinated by ICG
• Total funding 6.6 mill €
• Project duration 1May 2009-1 May 2012
Call
• Title: Prediction of triggering and risk assessment for
landslides
–
–
–
–
–
Taking into account climate change and human activity
Forecast landslide hazards and detect risk zones
Quantify triggering mechanisms, conditions and thresholds
Develop generic QRA frame for a better risk management
Help to choose an appropriate set of mitigation and prevention
measure
Main aims of SafeLand
• Evaluate the changes in landslide risk pattern in Europe
caused by climate change, changes in demography and
human activity, and policy changes
• Provide policy-makers, public administrators, researchers,
scientists, educators and other stakeholders with improved
methods for the assessment and quantification of risk
associated with landslides
• Provide guidelines for choosing the most approriate risk
management strategies
Global change = Climate change +
Changes in demography
I. Changes in demography
United Nations estimate:
The World population will
reach 9 billion by the
year 2050.
In 2007 for the first time in history more
than 50% of the World population were
living in cities.
Population trends in Europe
United Nation's prognosis of Europe's percentage of urban population
United Nations' prognosis of Europe's population
90
750000
700000
Percentage urban population (%)
Total population
Population (thousands)
650000
600000
Urban population
550000
500000
450000
400000
350000
80
Switzerland
All Europe
70
Austria
Italy
60
Romania
50
40
30
300000
20
250000
1950
1960
1970
1980
1990
2000
Year
2010
2020
2030
2040
2050
1950
1960
1970
1980
1990
2000
2010
2020
2030
Year
United Nations’ prognosis of the total population and urban
Population in Europe until the Year 2050
2040
2050
II. Climate change:
IPCC Fourth Assessment Report
IPCC Fourth Assessment Report
• Significantly increased precipitation in eastern parts of
North and South America, northern Europe and northern
and central Asia.
• The frequency of heavy precipitation events has increased
over most land areas - consistent with warming and
increases of atmospheric water vapour
• Very likely that hot extremes, heat waves, and heavy
precipitation events will continue to become more frequent
• Likely that future tropical cyclones will become more
intense, with larger peak wind speeds and more heavy
precipitation
Other factors affecting landslide risk
• Changing land-use (meadows, pastures, abandoned lands,
forests) which may influence the soil moisture availability.
• Changes in vegetation species, vegetation cover and
vegetation root characteristics (human-induced or climateinduced); deforestation and timber harvesting.
• Expansion of new developments and facilities (roads, train
lines, buildings) which may change slope geometry or
hydrology.
• Advances in landslide science, in particular monitoring and
remote sensing technologies, early warning systems, and
basic understanding of landslide mechanisms.
Scale:
Detailed (slope)
SafeLand is
organised in
five
Techincal
Areas (+ 3 nontechnical ones),
and 21 Work
Packages
Area 1
Improving knowledge on
landslide hazard (triggering
and run-out models)
Regional
Scale:
Detailed (slope)
Regional
Area 2
Quantitative
Risk Assessment
(QRA)
European
Scale:
Scale:
Regional / Local
Area 4
Monitoring technology
development for prediction
of behaviour of sample sites
Area 3
Global change scenarios
and their impact on landslide
hazard and risk patterns
European
Scale:
Detailed (slope) / Regional
for physical measures and
early warning
and
Societal
for other risk mitigation
measures
Area 5
Risk management
Detailed (slope)
Regional
Area 1 - Landslide triggers and run-out
1. Identification of mechanisms and triggers
(UNIMIB)
2. Geomechanical analyses of weather-induced
triggering processes (AMRA)
3. Statistical studies of thresholds for precipitationinduced landslides (ICG)
4. Landslides triggered by anthropogenic factors
(ICG)
5. Run-out models (FUNAB)
6. Identification of models best suited for QRA
(AMRA)
Which climate indices are relevant for landslide
triggering?
• Water is the main culprit. Intensity and duration of
precipitation, air-temperature, air-humidity and wind speed
(governing snow-melt) are some of the relevant factors
associated with triggering of landslides.
• Precipitation-induced landslides are usually triggered
during rare events at rainfall intensities with return period of
50 to 200 years.
• The duration of the rainfall influences the depth of the
sliding surface, as the rainfalls with longer duration will
infiltrate deeper into the soil and cause slides at greater
depths.
Which climate indices are relevant for landslide
triggering?
•
The characterisation of extreme precipitation events is
typically done on the basis of daily rainfall data using the
following indices:
•
•
•
•
•
•
RX1day: annual maximum 1-day precipitation
RX5day: annual maximum consecutive 5-day precipitation
R10mm: annual count of days when precipitation > 10 mm
R20mm: annual count of days when precipitation > 20 mm
R95p: annual total precipitation when rainfall > 95th percentile
R99p: annual total precipitation when rainfall > 99th percentile
Are these the relevalant indices that
should be focused on in SafeLand?
Area 2 - QRA
1. Harmonisation and development of procedures
for quantifying landslide hazard (UPC)
2. Vulnerability to landslides (AUTh)
3. Development of procedures for QRA at regional
and European scale (UPC)
4. Identification of landslide hazard and risk
“hotspots” areas (ICG)
Quantitative Risk Assessment (QRA) of
landslides or slope failures
•
To evaluate the necessity of risk mitigation,
one must first quantify the risk:
–
–
–
–
–
–
(1) What can cause harm? → threat identification
(2) How often? → landslide occurrence frequency (hazard)
(3) What can go wrong? → consequence of landslide
(4) How bad? → severity of the consequence
(5) So what? → acceptability of landslide risk
(6) What should be done? → landslide risk management
Area 3 - Global change scenarios
1. Climate change scenarios for selected regions
in Europe (MPG)
2. Human activity and demography scenarios
(BRGM)
3. Landslide risk evolution in selected ”hotspot”
areas (BRGM)
Possible hotspots
Downscaling area for
climate models
In case study areas in climate scenarios at
10km x 10km grid will be evaluated.
Global change = Climate change +
Changes in demography
Vulnerability evolution
Exposure evolution
Hazard evolution
2008 Risk map
New risk map in Year 20xx
Area 4 – Monitoring technology
1. Short-term weather forecasting for shallow
landslide protection (CMCC)
2. Remote sensing technologies for landslide
detection (UNIFI)
3. Evaluation and development of reliable
procedures and technologies for early warning
(GSA)
Area 5 – Risk management
1. Toolbox for landslide hazard and risk mitigation
and prevention measures (ICG)
2. Stakeholder process for choosing an appropriate
set of mitigation and prevention measures
(IIASA)
Definition of Risk
Risk = Hazard x Consequences
R=H.E.V
H=
E=
V=
Hazard (temporal
probability of a threat)
Value of element(s)
at risk
Vulnerability of
element(s) at risk
Landslide risk management framework
(JTC1 experts)
R I S K
M A N A G E M E N T
RISK ASSESSMENT
RISK ANALYSIS
Political
Aspirations
Other
constraints
Budget
HAZARD ANALYSIS
Social
demands
Elements at
risk
Regulation
Vulnerability
Risk
acceptance
criteria
Temporal
Spatial
probability
Frequency
analysis
LANDSLIDE (DANGER)
CHARACTERISATION
Mechanics, Location
Volume,Travel Distance
and Velocity
Consequences
Values
Judgement
Risk mitigation
Control options & Control plan
Monitor and
Review
Vulnerability
• Natural science perspective: Physical vulnerability of the
elements at risk
• Social science approach: Attention is directed to the
underlying structural factors that reduce the capacity of the
human system to cope with a range of hazards
Risk Management
• Define acceptable risk criteria.
• If estimated risk is less than the acceptable risk,
do nothing.
• If estimated risk is greater than the acceptable
risk, then
• Implement measures to reduce the risk (mitigation), or
• Redefine the acceptable risk criteria.
Risk management objectives
• Propose mitigation and prevention measures, and produce
harmonised toolbox of technically and economically
appropriate (and innovative) prevention and mitigation
measures based on experience and expert judgement
• Develop a risk-communication and stakeholder-led
participatory process for choosing the prevention and
mitigation measures that are most appropriate from the
technical, economic, environmental and social perspectives
Takk for
oppmerksomheten!