Transcript スライド 1

International Symposium “Cities at Risk”
Sea-Level Rise and
Coastal Vulnerability
Nobuo Mimura
Institute for Global Change Adaptation Science
Ibaraki University/IR3S
1
Contents of Presentation
1. Global and Regional Picture
- Climate Change and Sea-Level Rise
2. Local and Individual Pictures
- Mangrove erosion in Thailand
- Cyclones in Bangladesh
- Tsunami in Maldives
- Coastal Protection in Tokyo
3. Challenges
1. Global and Regional Picture
–Climate Change and Sea-Level
(IPCC AR4, 2007)
Global Mean Sea-Level
- 17cm rise for the
past 100 yrs
- Present speed of
SLR is 3.2 mm/yr.
- In a long tem,
collapse of
Greenland ice sheet
may induce 2-7m
SLR.
(IPCC WGI AR4, 2007)
Temperature Rise
(2071~2100)
5
Tropical Cyclones 1949-2007
Estimated Typhoon Parameters
Lowest Center Pressure
Maximum Wind Velocity
Lowest Cent. Press. [hPa]
860
880
900
920
940
960
980
1000
-
860
880
900
920
940
960
980
1000
1013
Maximum Wind Vel. [m/s]
17
20
30
40
50
60
-
20
30
40
50
60
Severity of Typhoon Effect (Hot Spots)
Severity
Rank１
Rank２
Rank３
Rank４
Rank５
Rank６
Rank７
Rank８
Rank９
Inundation by Local HWL(Tide)
Inundation by Local HWL
+ SLR 59cm
Inundation by Local HWL
+ SLR 59cm
+ 100yr Strom Surge
Asia
362 million people
(10.2% of 2000 pop.)
Population Growth in Asia
Vulnerability of Maga-deltas
・Several millions more people will be flooded annually.
・Proactive and planned adaptation is necessary.
Extreme: >A million（by 2050）
High:
50 K to one million
Medium： 5K to 50 K
（IPCC WGII AR4, 2007）
2. Individual Pictures
Case-1
Erosion of
Mangrove
in Thailand
Landsat image around river mouth of Chaophraya
Erosion at the
front
Land Subsidence in Bangkok
Source:Somkid(2002)
Case-2
Tropical
Cyclones in
Bangladesh
History of Cyclone Damages
Date
Max Wind
(m/s)
Max Wind
Radius (km)
Storm surge
(m)
Casualties
（people）
30 Oct 1960
57.5
74
4.57-69.10
5,179
9 May 1961
40.8
64
2.44-3.05
11,468
28 May 1963
55.6
74
4.27-5.18
11,520
11 May 1965
58.1
74
3.66
19,279
31 May 1965
44.7
64
6.10-7.62
12,000
23 Oct 1966
40.3
64
6-6.67
12 Nov 1970
61.7
74
6.10-9.14
24 Nov 1974
44.7
64
2.8-5.2
9 Nov 1983
33.3
64
3.05-4.57
11,069?
25 May 1985
42.5
64
3.05-4.57
11,069?
29 Nov 1988
44.4
64
1.52-3.05
5708
29 Apr 1991
62.5
74
6.10-7.62
138,000
25 Nov 1995
58.3
74
-
650
19 May 1997
55.6
74
4.6
126
26 May 1997
41.7
74
3.0
70
16 May 1998
45.8
74
1.83-2.44
850
500,000
200
-
Combining Early Warning System and Hard Measures
Cyclone Shelter (Chittagong Port City )
Evacuation Road to a Cyclone Shelter
Coastal Dike
Case-3 2004 Indian Ocean Tsunami
- Coastal vulnerability and countermeasures
(News Week Japanese 1/12)
Male Island
(Preliminary Report of Survey Team, JSCE, April 2005)
埋め立て地と浸水地域の分布
(Preliminary Report of Survey Team, JSCE, April 2005)
Male Island
Case-4 Coastal Protection in Tokyo
Increased
Population at
Risk in Tokyo
Affected Pop (million)
HWL
2.3
HWL+SLR
3.2
HWL+SLR+SS
4.2
History of Flood Damage in Japan
Dead/Missing
Death Rate (Dead/Population)
Changes in Death Rate Due to Natural Disaster
(1945～1990)
Year
3. Challenges
1. Asian cities in low-lying deltas will be increasingly at risk.
- Impacts of climate change and SLR
- Large population growth and development
2. Development policies and city management aim mainly
at short-term goals.
- Today’s problems
- Large portion of today’s investments will be affected by
CC/SLR
i.e. 10 to 50% of investment to infrastructure such as
coastal dikes, loads, bridges, irrigation facilities.
3. How to incorporate the future risk of CC/SLR into
today’s management.
- Role of adaptation: increase the preparedness with
solving today’s problems
- Win-Win approach both to present and future
problems
- Mainstreaming adaptation
4. Major target of adaptation for coastal cities is
management of growth.
- Impact and vulnerability assessment is the first step.
- Regulate migration of population
- Incorporate adaptation to CC in to infrastructure
construction and city planning
Thank you very much!