Water –related Disaster Risk Information for Risk Reduction
June 23, 2014
The 6th Asian Ministerial Conference on Disaster Risk reduction inBangkok, Thailand

Directorate General of Water Resources
Ministry of Public Works
Republic of Indonesia
1•Information for Preventive Investment•

Information for Preparedness and Response•

Summary2

Disaster Risk Management•

Mitigation

DISASTER
Response

to prevent disasters
Preparedness•Preparedness
to ensure effective response•

Response

Recovery

Mitigation

to reduce adverse impacts during the flooding•

Recoveryto assist the affected communities to rebuild themselves

We need to consider what information is necessaryin accordance with each stage3

Effect of Preventive Investment• Investment for prevention can reduce
disaster damages largely
In case of “TOKAI devastating flood” in Japan 2000,
Prior investments of JPY71.6 billion made it possible to reduce disaster damage
by about JPY550 billion.

Effect of disasterprevention projects:
Equivalent of approx.
Amount of damage:

JPY550 billion

Approx.

Waterlogged conditions due to heavy
downpours in Tokai region

JPY670 billion

Amount of disaster damage
incurred from heavy
downpour in Tokai region

Afterimplementation ofprojects:
Estimated amount ofdamage:Approx.
JPY 120 billion
Estimated amount ofdamage after
implementation of projects

Projects costs:
JPY 71.6 billion in total
Costs for preventing
recurrence of disasters** Special Emergency Project for Shonai Riverand Shin River Disaster Prevention
Strategies(2000 to 2004).

4*Number of fatalities exclude those who dead by tsunami

100

2006

Flood Management Cost (2000 price)(hundred of million yen)GDP(2000 price) <billion yen>
←Tokai Flood←Debris Flow in Kagoshima Harihara←Fukushima Tochigi Flood, Kochi Flood←Debris Flow in Hiroshima
Kumamoto Flood←Typhoon No.17, No.18, No.19
Pyroclastic flow of Unzen‐Fugen‐
Dake ←August Flood in Kyusyu←Nagasaki Water Disaster←Western‐Sanin Water Disaster

Number of Fatalities

2001

1996

1991

←Typhoon No.6, Landslide inNagano←West‐Japan Water Disaster←Typhoon No.17←Typhoon No.6, No.7, No.9

GDP (2000 price)

1986

1981

1976

←Second Typhoon Muroto

Flood Management Cost (2000 price)

1971←West‐Japan Flood←Typhoon Toyamaru←Isahaya Flood←Typhoon Karinogawa←Typhoon Ise‐
←TyphoonBayNo.24, No.26←West‐Japan Water Disaster

1,0001966

1961

1956

1951

←Typhoon Kathleen←Typhoon Ion←Typhoon Kitty←Typhoon Jane
←Typhoon Ruth

10,0001946

Number of Fatalities (people)(logarithmic)

Effect of Preventive Investment
Number of Fatalities by water‐related disasters in JAPANGDP and Budget for Flood Management in JAPAN (2000 year price)

1

Water‐related Disasters Statistics in Japan*GDP : 1980-2011(2000 price), 1946-1979(1990 price)

30,000<600,000>
25,000<500,000><400,000>

20,00015,000<300,000>
10,00010<200,000><100,000>

5,000

<0>

05

Disaster Risk Management Information
for Preventive Investment• Evaluate the Risk
- Hazard expressed in terms of frequency- Exposure of human activities- Vulnerability of elements at risk

• Show(1) the Current level of Risk
(2) the Effect of Preventive Investment• Monitor the Progress6

Current level of Risk and Effect of Preventive Investment•

Necessary to be understandable for Public and Policy-makers•

Case of YAHAGI river in JAPAN

Goal of mid‐term improvement plan (Return period): about 50 years
Current Level of Risk
‐ Area under possibility of inundation: 7,300 ha(as of 2009)‐ Population in the above area
: 130,000‐ Houses in the above area
: 50,000
Effect of Preventive Investment: Zero(Upstream)

Propose Solutions

TOYOTA
City

Total Cost for Investment:
39.9 billion JPY
Total Benefit

ANJO
City

TOYOTA
CityOKAZAKI
City

HEKINANCity(assets and properties which areprotected from flood by investment)

HEKINANCityNISHIOCity

752.2 billion JPY(as of 2009)(Sea)

Inundation
Depth

NISHIO
City7

Monitor the Progress• Indicators to monitor progress• Sample Indicators (The 3rd five-year planon infrastructure development)- Increase in rate of river improvement to the mid-term goals(equivalent to about 50-year floods)
Length of improved rivers＝ Length of rivers which are to be improved for the mid‐term goals
Current (end of JFY 2011)

Goal after 5 years (end of JFY 2016)

Rivers managed by Central Gov.
: 72%
Rivers managed by Prefecture Gov.: 57%

Rivers administrated by Central: 76%Rivers administrated by Prefectures: 59%- Reduction of the number of houses which will be still
under possibility of inundation in case of flood recurrence
Current （end of JFY 2011）

Goal (end of JFY 2016)

about 61,000 houses

about 41,000 houses

8Economic Losses Caused by Floods
Inundation area decreasing, but Density ofFlood Damage increasing, due to urbanization

Density of Damage Cost(thousand yen / ha)
70000

Damage to General Assets(10 billion yen)
140

60000

120

50000

100

40000

80000
2007

20

1997

101992

10000

1987

40

1982

20

1977

20000

1972

60

1967

Inundated area(10,000 ha)

1962

30000

2002

•

Water‐related Disasters Statistics in JAPAN
Total Inundated Area (10,000ha)
Area of Inundated (Residential & Other Property) (10,000ha)
0Density of Flood Damage to General Assets
Damage to General Assets (2000 Price)9

Information at Preparedness and Response Stage•

Natural Dam in Way Ela River, Ambon, Indonesia
Natural Dam (H=170m, V=25mil m3) by large‐scale landslides in July 2012

Reservoir

LandslideJakartaAmbon

NaturalDam

Approximately 5,000 local residents lived
2 km downstream from natural dam

Source; Ministry of Public Works

Negari Lima
Village10

Information at Preparedness and Response Stage
Case of Natural Dam in Indonesia
What is necessary information in this case?
•Real‐time Water level
Because…
‐ major mechanism of natural dam collapse iserosion caused by overflow from reservoir‐ local community needs criteria for the effectiveevacuation by water level11

Information at Preparedness and Response Stage
Case of Natural Dam in Indonesia•

Installation of
Real‐time Water level gauge

Installation in Feb. 2013

•Decision of Warning
Water level for Evacuation Order
195
Water Level in Reservoir in July 2013

(m)
194
193

191m (Level for Evacuation order )192

25th : overflow and collapse

191
190

(date)

189
1011

12

13

14

15

16

171820

21

22

23

24

25

12

Case of Natural Dam in Indonesia••

Houses of 422 households, 2,600 residents, were destroyed
Most residents evacuated to safe places before debris flood
reached the village ( 3 persons dead and missing )Negeri Lima Village

Village was heavily destroyed by debris floodcaused by collapse of natural dam

Natural Dam
ReservoirSource; Ministry of Public Works13

Summary•

Necessary information differs in accordancewith stages•Information is necessary to be understandable tothe public as well as decision-makers•

Preventive Investment (Mitigation) is quite
effective to reduce disaster risk•

Collaboration and Information Sharing among
related stakeholders is quite significant atPreparedness and Response Stage14

ありがとうございます15