Transcript Urban Flood & Climate Change

Urban Flood & Climate Change
----information from APWMF and SIWW
Jinping LIU
Hydrologist
Typhoon Committee Secretariat
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The Asia-Pacific Water Minister’s Forum (APWMF)
June 28, 2010
Jointly organized by MEWR and
PUB of Singapore , and in
cooperation with APWF.
Attended by Ministers and
water leaders from 15 countries.
Themed ‘Water Security—Good
Governance and Sustainable
Solutions’.
Articulated the region’s water
issues, policies and solutions.
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Singapore International Water Week (SIWW)
June 28 ~July 1, 2010.
Inaugurated with 2nd World
Cities Summit (WCS).
Themed ‘Sustainable Cities:
Clean and Affordable Water’
for SIWW.
Themed ‘ Liveable &
Sustainable Cities for the
future’ for WCS.
Around 10,000 participants from
more than 100 countries and regions.
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Today’s presentation
 Urbanization Affecting Flood Risk
 Climate Changes Affecting Flood
Risk
 Approaches: Adapting to Climate
Change
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Urban/rural population for less and more developed region
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Urbanization - Tsurumi River Basin
1958
Urbanization
Population increased by 1.7
Rate
million in 40 years.
85% of the river basin urbanized.
It has become a typical urban river.
1975
1975
1995
1995
Natural
Urban
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Influence of Urbanization on Flood Risk
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Rainfall pattern is changed.
3400
2900
Heavy rainfall in a
city of Japan
(1990~1999)
2400
1900
1400
900
1901
1921
1941
1961
1981
2001
Annual Precipitation in Macao in the
period of 1901~2008
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Hydrological response is changed.
•Less infiltration
•More runoff
•Higher velocity
•Shorter travel time
•Higher peak flows
•More frequent channel
forming flow
•Lower low flows
= Extremes
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Discharge
Present
Past
Intensity mm/hr
Flow Increase & Time of concentration Decrease
70 mm/hr
frequency
1:50 yr
1:10 yr
20
60
duration
Time
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Today’s presentation
 Urbanization Affecting Flood Risk
 Climate Changes Affecting Flood
Risk
 Approaches: Adapting to Climate
Change
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Heavy Precipitation Events:
Frequency increases over most areas
Anomalies (%) of the
global annual time series
defined as the
percentage change of
contributions of very wet
days from the base
period average.
Kobe, Japan
2008
(Prof. Toshio Koike, The University of Tokyo )
IPCC AR4
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IPCC AR4
Projected changes in extremes:
It is very likely that heavy precipitation events will continue
to become more frequent.
> 90%
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Recent trends, assessment of human influence on the trend and
projections for extreme weather events for which there is an
observed late-20th century trend.
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Ratio of Daily 10year Probable Rainfall between 50 years later
according to A1B and the current, from 17 models
IPSL-CM4
MIROC3.2(hires)
GFDL-CM2.0
CGCM3.1(T63)
CCSM3
MIROC3.2(medres)
GFDL-CM2.1
CSIRO-Mk3.0
ECHAM5/MPI-OM
ECHO-G
GISS-AOM
MRI-CGCM2.3.2
CNRM-CM3
PCM
INM-CM3.0
CSIRO-Mk3.5
CGCM3.1(T47)
Average=1.2
(from 17 models)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
Araki & Koike, 2008
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Design Rainfall
Current Design
Rainfall
1
Design Hydrograph
Future Design
Rainfall under
Climate Change
Discharge
(m^3/s)
1.2
Hydrological
Model
Climate Change
Current Climate
T
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Design Flood Control
Future Design
under
Climate Change
Current Design
Target Flood
safety level
Current Flood
safety level
1:150
1:80
Future
under
climate
change
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1:150
Uncertainty
1:80
Basin wide
measures
Climate Change Impacts on Flood Control Plan
in Indonesia
10year Probable flood
50 years later
10year Probable flood
Current Climate
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Today’s presentation
 Urbanization Affecting Flood Risk
 Climate Changes Affecting Flood
Risk
 Approaches: Adapting to Climate
Change
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• In responding to Climate Change, investment for
prevention under uncertain targets is extremely
difficult, especially for developing countries.
• The best option is to take an adaptive approach that
build climate resilience into development strategies.
• Adapting to What?
– As the future is unknown, adaptation should be
flexible, incremental and capable of incorporating
changes based on new knowledge.
– It should be a continuous process guided by
sustainability concerns and address multiple needs.
End to End Approach on Climate Change Adaptation
Scientific approach
Climate
models
Information
ordinary
water
Flood
control
system
ground
water
Storage
drought
Basin-scale prediction
of quantity & quality
Early warning
Treatment
Environ-ment
Human life
Industry
Human
Behavior
Filed survey
Economic
Behavior
Drought
Disaster potential
Innovative
technology
- Flood control
- quality
control
implementation
Integrated
Observed
Data Sets
flood
Adaptation
options
Decision making
Down-scaling
Flood
Disaster potential
Current facility,
plan,
management
Impact assessment
Multi-model
ensemble (MME)
Water quantity
and quality
prediction
Water allocation & cost
Process
Study
Quantifying
uncertainty
Socio-economical approach
Engineering Approach
Allocation
policy
Land use
etc.
Monitoring
evaluation
(Prof. Toshio Koike, The University of Tokyo )
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Rotterdam Climate Adaptation Strategy 1.0
CLIMATE PROOF
ROTTERDAM ....
Accessiblity
City Climate
Urban Water System
Flood Management
Adaptive Building
Road map
CLIMATE PROOF
ROTTERDAM 2025
Action
Implement
Monitoring
Assessment
knowledge
CLIMATE PROOF
Rotterdam 2009
Arnoud Molenaar
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Concluding Remarks
• Climate Change, Urbanization and Urban migration are
the greatest challenges for urban flood disaster risk
reduction.
• Flexible adaptive measures - adaptive adaptation should be mainstreamed. Innovative holistic approaches
based on risk assessment are needed to achieve this.
• Urban flood is not isolate issue. UFRM should be
integrated with holistic urban system.
• Urban flood is a kind of resources. UFRM is not to simply
discharge flood out side of city, but to promote the
beneficial and abolish the harmful.
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“The Shapers of New Asia”
“They include YOU and ME….”
Thanks
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