Transcript Present

JICA’s Initiative on
Climate Change Adaptation in
Water Related Disasters
水分野における
Mikio Ishiwatari
Senior Advisor, Japan International Cooperation Agency
ISDR Asia Partnership Technical Workshop to Develop the Regional Roadmap for
Promoting Regional Cooperation on Disaster Risk Reduction and Climate Change
Adaptation
1-2 July, Bangkok
outline
1.
2.
3.
4.
5.
Situation in Japan
Staitionarity is dead
JICA’s new initiative
Case study
Conclusion
Recent change on Climate in Japan
Daily rainfall over 200mm is significantly increasing
日降水量200mm以上の日数
Incidence of daily rainfall over 200mm per year
（ Number of incidence ）
18
16
1978～2007
Average
days
1901～1930
14
5.1
Average
days
年 12
間
合 10
計 8
日
数 6
3.5
Source: JMA
4
2
0
1900
1910
1920
1930
1940
1950
1960
1970
1980
1990
2000
（year ）
2010
年
Hourly rainfall over 100mm is increasing
（ Number of incidence ）
Incidence of hourly rainfall over 100mm per year
10
1987～1997
1976～1986
1.7
5
4
2.0
5
Average
days
8
Average
days
7
Average
days
1998～2008
3.6
5 5
5
4
4
4
3
2 2
1
0
2
2
1
2
1
0
1980
2
1
0
1985
3
2 2
2
1
1
0 0 0
1990
1995
0
2000
2005
Source: JMA
（year ）
Projection of future Climate
Rainfall after 100years is projected
to increase 10 to 30% (max. 50%)
bigger increase in northern area
Ａ
Future rainfall projected as a
median value in each region
The maximum daily precipitation
GCM20 (A1B scenario).
Ｂ
Flood Safety Level
Average rainfall in 2080-2099
Average rainfall in 1979-1998
Decline of
flood safety level
100
75
50
25
Present
0
現
計
画
北
海
道
Ａ
東
北
Ｂ
Increasing rainfall intensity make flood safety4
level significantly lower than present
Basic concept for managing increasing risks
- Multiple measures in flood management Future (100years later)
Present
1/150
1/150
Target of
Safety
Level
Runoff
regulation
measures
in basin
Present Safety
Level deteriorate
significantly by
future increase of
rainfall
1/40
Target of
Safety
Level
Reevaluated
safety level
Runoff
regulation
measures
in basin
Crisis management
and Evacuation
5
Collaboration with regional Development
Crisis management and Evacuation
2. Stationarity is dead
2. Stationarity is
1)
Dead
we are in trouble
☺Conventional Method of Water Planning
Assumption: fluctuate within an unchanging envelope of
variability
☹

Under changing and uncertain climate
Climate is changing
Return period (ex. 100 years flood or 10 years drought)
is never foundation of planning

Prediction possible, but with uncertainty
New Designing methods of water infrastructures
are needed
River bank heights, dam reserve capacity, bridge heights etc.
1) Milly P. C. D., J. Betancourt, M. Falkenmark, R. M. Hirsch, Z. W. Kundzewics, D. P. Lettenmaier, R.
J. Stouffer (2008), Stationarity is Dead: Whither Water Management, Science. 319, p. 573-574.
Furthermore……
2. Stationarity is Dead
Is flood Control Philosophy Dead, also?

Can we continue to construct higher dykes
according to increasing flood scale?
2. Stationarity is Dead
Flood Control Philosophy is Dead as Well.


Conventional philosophy is abandoned.
“Long liner bank system along river from
river mouth to mountain”
Proposed philosophy
“Multi-layered measures in river basin”
1) Step 1: Strategic area protect by structures
2) Step 2: Urban planning and land use
regulation for risk areas
3) Step 3: CBDM
2. Stationarity is Dead
Sustainable society resilient to changes
1.
2.
3.
to respond continuously changing climate
to plan and implement infrastructure projects
through predicting future impacts with
uncertainty
to change systems of water management
according to developing technology for
prediction and adaptation of climate change
3. JICA’s new initiative
＜conventional project>
Objective: to mitigate human
and economic losses
Historical hydrometrological data
Target setting
To decide target floods scale
based on probability analysis
Run-off Analysis
<Project>
Structural
M easures
（such as
river bank,
and dam）
＜Climate Change Adaptation Project＞
Objective: to minimize human loss
Historical hydrometrological data
probability analysis
on target floods
Runoff and
Inundation analysis
Climate Change
Prediction
Evaluation on Impact
on Extreme Events by
Climate Change
Coping Mechanism
Analysis
Target setting
1) Strategic Area Protection by Structural Measures
2) Land Use Regulation
3) Community-based Ri sk Management
＜Project＞
Non-structural
M easures （such as
flood early
warning）
River Basin Governance
Structural
Measures
Urban,
Regional
Planning
（ land use
regulation）
Monitoring
Non-structural
Measures
（early warning,
Evacuation）
CBDM
Poverty Alleviation,
Vulnerability Consideration
Climate change prediction
ensemble of GCM
Pahang
Muar
Climate change
adaptation measures

Governance at river basin level









various sectors, organizations, stakeholders are
involved
Need for consensus building and responsibility
sharing
Structure measures
Non-structural measures, early warning and
evacuation
Land use regulation
CBDM
Capacity Development
Monitoring
Poverty alleviation and consideration on
vulnerability group
4. Case study
4-1 Tagaloan River Basin, the Philippines
100 yrs flood
→ 25-50yr flood in 2100
50 yrs flood
→ 25yr flood in 2050
Tagaloan River Basin, the Philippines
Scenario
B1
Design rainfall
(mm)
Return
period
(year)
Probable Flood
Discharge
(m3/s)
5yr
10yr 25yr 50yr 100yr
25yr
50yr
-
125
142
164
181
198
4190
4770
2050
11
150
170
197
217
237
4780
5720
2100
14
161
183
211
233
255
5400
6150
2050
20
138
157
182
200
219
4650
5290
2100
29
142
162
187
206
225
5030
5430
Status quo
A1F1
Increase
rate of
rainfall
intensity
(%)
Tagaloan River Basin, the Philippines
Planning
Original MP
Revised MP
4-2．Metro Manila Suburb, Philippines :
Cavite Area
Qp=1,300m3/s
Year 2050 under Secenario A1FI
1400
Qp = 1,090 m3/s
Year 2050 under Secenario B1
1000
Qp = 880m3/s
States Quo
3
Discharge (m /s)
1200
800
600
400
200
0
0
Fig. 1 General Map of Study Area
6
12
18
24
Time (Hour)
River Basin
Catchments Area
(km2)
River Length
(km)
Imus
115.5
45.0
San Juan
147.76
43.4
Canas
112.32
42.0
Residual
32.84
-
Total
407.4
30
36
42
48
危険地域の家屋数
Houses at risk area
2008
21,800 houses
×3
2050
74,200 houses
Probable Flood Inundation Area (km2)
Case
No.
1
2
3
4
5
6
7
Scenario of Climate Change
Urbanized
Ratio
Status Quo
26%*
States Quo
In 2050 under B1 Scenario
43%**
In 2050 under A1FI
Scenario
States Quo
In 2050 under B1 Scenario
65%***
In 2050 under A1FI
Scenario
Number of Houses/Buildings
Inundated (thousand houses)
Flood
Flood
Depth
Depth
Total
below 1m above 1m
Flood Depth
below 1m
Depth
above 1m
Total
31.51
35.82
41.10
1.05
1.50
2.52
32.56
37.32
43.62
20.1
31.4
35.5
1.7
2.9
4.4
21.8
44.64
41.05
43.92
3.54
2.45
2.97
48.18
43.50
46.89
38.4
56.4
60.1
5.9
7.2
8.5
44.3
63.6
68.6
47.27
3.98
11.2
74.2
51.25 63.0
34.4
39.9
multiplication of CC and Urbanization
気候変動
Climate Change
都市化 Urbanization
表面流
Surface flow
危険地域の家屋
Houses at risk area
雨
Rain
洪水
Floods volume
海面上昇
Sea Level
危険地域
Risk area
適応策検討 Climate Change Adaptation
遊水地計画を将来拡張する可能性
→都市計画に開発抑制地域として線引き
１．河川工事・遊水地
River improvement works
Off-site Flood Retarding Basin
Partial River Improvement Section
3. 調整池Retarding
2.土地利用規制
Land Use Control
Basin in Urban area
適応策 Climate Change Adaptation
土地利用規制 Land Use Control
Description
Peak River Discharge
before Retarding
Peak River Discharge
Fig. 22
after Retarding
Reduction of Peak
Storage
Land Zoning in the Lower Reaches of StudyArea
Area
Discharge
Volume
Proposed in the
Study
430 m3/s
245 m3/s
185 m3/s
1.87 (106m3)
45ha
Required in 2050
B1 Scenario
550 m3/s
245 m3/s
305 m3/s
3.01 (106m3)
75ha
Required in 2050
A1FI scenario
690 m3/s
245 m3/s
445 m3/s
4.06 (106m3)
100ha
気候変動適応 Climate Change Adaptation
宅地での調整池 On-site Regulation ponds
New Sub-Division
Dry Type
Creek
On-site Flood
Regulation Pond
• Offset increment of peak
runoff discharge
• Control sediment runoff
(3% of Sub-Division)
Wet Type
適応策 Climate Change Adaptation
ソフト対策 Software measures
ハザードマップ
For Evacuation
For Warning
簡易観測
River Water Level Indicator for Flood
Warning and Evacuation
適応策 Climate Change Adaptation
コミュニティ防災 Community based disaster management
適応策 Climate Change Adaptation
コミュニティ防災 Community based disaster management
5. conclusion




Climate is changing in Japan, and new policy is
reported.
Startionarity is dead, flood control philosophy
either?
JICA’s Handbook for Climate Change
Adaptation in Water
Proposed method of CCA in flood risk
management is applied in the Philippines
JICA handbook
Ver.0 was produced
Ver.1 will be issued at the end of FY2010
Comments are welcomed
[email protected]
Climate change prediction
Study in South Western Sri Lanka
Study Area
River Basin
C.A.
Kalu River basin
2,719km2
Kelani River basin
2,292km2
Gin River basin
932km2
Nilwara River basin
971km2
Study Schedule
21 months
(from January 2010 to September 2011)
First Year
2010
Work in
Sri Lanka
Work in
Japan
Second Year
2011
Climate change prediction
Study in South Western Sri Lanka
Projected Rainfall Data from CMIP3
(1) Data
Collection
Projected Rainfall Data of GCM20
(1979-1998, 2080-2099)
Recorded Rainfall Data in Project Area
Mesh Rainfall data from
APHRODITE daily precipitation
(2) Examination of Appropriateness of GCM20 by
Comparison with CMIP3 Rainfall Data
(3) Bias Correction and Statistic Downscaling
(4) Evaluation of Flood Risk
(Hydrological and Hydraulic Analyses)
Note: CMIP3: Phase 3 of Coupled Model Intercomparison Project
GCM20: General Circulation Model (20km grid)
APHRODITE: Asian Precipitation-High Resolved Observational Data
Integration Towards Evaluation of the Water Resources
Impacts of sea level rise:
Increase of areas below sea level, and of risks of inundation due to high tides
Increase of risks of inundation due to high
tides
*At present, it is not clear whether the increase of inundation
risk is attributable to global warming or not but there may be
a possibility.
About 100
約100回
times
Frequency
回(times)
120
100
80
60
40
Less than
20 10回以下
ten times
0
年
2000
1990
1980
1970
1960
1950
1940
1930
1920
About約40回
40 times
1910
1900
Annual frequency of inundation of St. Mark's Square in Venice, Italy (Graph prepared based on the Economics of Climate Change by Stern
Review.)
冠水回数
25
17
15
12
10
10 11
2005
2004
2003
0
2002
1
2001
2
2000
0
3
1999
1992
0
1998
1991
0
1996
1
1995
1
1994
0
1993
1
0
1997
7
4
1990
5
1989
Itsukushima Shrine in Hiroshima was inundated
less than five times a year in the 1990s. about ten
times in the 2000s. 22 times a year in 2006 and is
still increasing.
22
20
2006
-St. Mark's Square in Venice was
flooded less than ten times a year at
the beginning of the 20th century.
increase to about 40 times a year by
1990 and to as many as 100 times a
year in 1996.
-250 times of inundation a year in 2006.
5. Impacts of
sea level
rise
Annual frequency of inundation
of the corridor of Itsukushima
Shrine in Hiroshima (Graph
prepared by the Chugoku
Regional Development Bureau
based on a diary of Itsukushima
Shrine.)
Increases of below-sea-level areas in three large bay areas (Tokyo Bay, Ise Bay and Osaka Bay)
Ashiya City to Osaka City
Kawagoemachi to Tohkai City
Yokohoma City to Chiba City
Areas with flood risks due to
high tides will increase.
Present
現状
海面上昇後
rise
After sea level
Rate of
increase
Area (km2)
面積（k㎡）
577
879
１．５
Population (in tens
of thousands of
people)
404
593
１．５
人口（万人）
倍率
Osaka Bay
Ise Bay
Tokyo Bay
*Prepared by the River
Bureau based on the
national land-use digital
information.
*Shown are the areas at
elevations lower than sea
level shown in a threedimensional mesh (1 km x 1
km). Total area and
population are based on
three-dimensional data.
*No areas of surfaces of
rivers or lakes are included.
*A premium of 60% is applied
to the potential flood risk
area and to the population
vulnerable to flood risk in the
case with a one-meter rise
of sea level.
５