Flood Hazard Mapping Project in Asia

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Flood Hazard Mapping Project in Asia
August 2003  KIKUCHI Ryosuke Director of 2nd
Research Department Infrastructure Development
Institute - Japan
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- Overview of Flood Damage -
Fig.-1 Affected by type of disaster and by period
(19731997)
Fig.-2 Average occurrence and damage of natural
disasters (19751999)
(Millions)
Source CRED, World Disasters Report 1999
Source Asian Disaster Reduction Center, Data
book of Asian Natural Disasters in the 20th
Century
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• 1.Background
• Economic growth, urbanization
• Explosion of population
• Concentration of population and property
• People who have never experienced a flood are
  moving in
• increasing numbers to flood-prone areas in many
  countries.
• Residents are less aware of the threat of floods.
  
• They are hardly prepared for floods.
• Suffering more serious damage once a flood
  occurs.
• It is time-consuming and costly to construct
  flood control
• facilities to lower the risk of flood damage.
• It is advisable to enhance local residents'
  awareness of the
• importance of flood protection efforts
  concurrently with
• the steady development of flood control
  facilities so that
• overall flood damage shall be mitigated. 

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2. History of Japan(1) Flood Record Maps

• Published by the Ministry of Construction
• Showing inundated areas during past floods
• With Hyetographs, weather conditions, etc.
• 125,000 150,000 base maps
• Delivered to local government offices, and mass
  media
• Displayed on the billboards of the offices

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Flood Record Map for the Tsurumi River Basin
June, 1966
Sept.,1976
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Public Acceptance of Flood Record Maps
Percentage of 4,781 Answers
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Public Opinion to Flood Record Map

• Indication of present status rather than past
  records was preferred. (36.9 of 185
  respondents, multiple answer)
• Larger and more detailed map to identify
  individual house was demanded. (25.2 )
• Inundation depth in addition to inundation area
  was thought necessary. (24.8 )
• More records for other floods requested. (8.3 )

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2.History of Japan(2) Flood Risk Area Map

• Inundation area and depth
• Calculation based on a model storm with 150-year
  return period
• Compiled for each river basin
• Publication through pamphlets, municipalities PR
  papers, mass media, etc.
• Map scale of 125,000 to 150,000

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Flood Risk Area Map for the Tsurumi River
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Public Acceptance of Flood Risk Area Maps
Percentage of 1,883 Answers
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Public Opinion to Flood Risk Area Maps

• More information was needed.
• Larger map for individual municipality(33 of
  1,799 respondents, multiple answers)
• Inundation areas and depths for more frequent
  storms (17 )
• Evacuation sites and routes (12 )
• No official protest was made despite prior
  concern.
• Necessity of a flood hazard map was confirmed.

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3. Definition of Flood Hazard Map   The
Flood Hazard Map herein referred to is a map
that graphically provides information on
inundation, as well as on evacuation in an
easy-to-understand format. The goal is to
quickly evacuate local residents in a safe and
proper manner in the event of floods. The map
is produced and publicized through a joint effort
by those in charge of disaster prevention and
those in charge of rivers and hydrology in the
respective local municipalities.
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4. Purpose
? For local residents -Raise the awareness of
the importance of voluntary disaster prevention
efforts and proper evacuation. - For the
prompt and smooth evacuation to avoid injury
 ? For local municipalities concerned
-Administrative staff to simulate emergency
drills and thus urges local municipalities to
develop disaster prevention and preparedness
countermeasures. (Evaluate land use plan, road
plan, refuge center and etc.)
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5. Information in Flood Hazard Map
(1) Information for Evacuation Predicted
inundation area, Inundation depth, Flood
concentration time Historical
inundation records Areas to be evacuated
Location of evacuation places and routes
Dangerous spots on evacuation routes Rules to
follow in cases of evacuation Communication
channels and systems for information on
evacuation Issuance criteria for evacuation
warnings
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5. Information in Flood Hazard Map

• (2) Information for educational use
• Flooding mechanism
• Topographic features and flooding types
• Real danger of flood, Predicted extent of
  damage
• Meteorological information
• Past flood records (rainfall, inundation, and
  damage)
• Rules to follow in cases of flood
• Explanation and directions to use flood hazard
  maps
• Preparedness against flood

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Hazard Map (Sukagawa City)
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(No Transcript)
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Information in Flood Hazard Map
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Information in Flood Hazard Map
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Information in Flood Hazard Map
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Information in Flood Hazard Map
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Information in Flood Hazard Map
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6. Effectiveness of Flood Hazard Map
According to the questionnaire survey conducted
immediately after the flood, the effectiveness of
the Flood Hazard Maps was satisfactorily verified
as stated below 1) The majority of the
local residents referred to the locations of the
refuges on the Flood Hazard Maps, and evacuated
to the proper refuges. 2) The number of
evacuees was 1.5 times more for those who
referred to the maps than for those who did not.
3) Residents who referred to the maps
commenced evacuation one hour earlier than those
who did not.
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Flooding in Koroyama City, August 1998
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lt Number of evacuees six hours after notice
advice to evacuate gt
Number of evacuees
Approximately one hour
1.5 times
Those who did not see the Hazard Map
Those who saw the Hazard Map
Notice to evacuate
Order to evacuate
Source Survey Report on Local Residents
Reaction during the Rainstorm in Koriyama at the
End of August 1988
Katada Laboratory, Faculty of Engineering, Gunma
University
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7. ESCAP/WMO Typhoon CommitteeHazard Mapping
Project
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ESCAP/WMO Typhoon Committee

• 1.Member (14)Japan, Cambodia, China, The DPR of
  Korea, Lao PDR, Malaysia, Philippines, Republic
  of Korea, Singapore, Thailand, Viet Nam, USA,
  Hong Kong, Macao
• 2.Compornent(5)
• Meteorology,
• Hydrology,
• DPP(Disaster Prevention and Preparedness),
• Training, and
• Research

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The schedule of implementation plan
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(No Transcript)
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(No Transcript)
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Pilot projects in Asian Countries(102)
Cambodia China The DPR of Korea Lao
PDR Malaysia Philippines
Republic of Korea Thailand Viet Nam Japan Myanmar
(PANEL) Pakistan (PANEL)
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Concluding Remarks In Japan and TC countries,
the importance of Flood Hazard Maps has
undoubtedly been recognized in recent years, and
now the preparation of the maps is progressing in
a positive direction. It has not been long since
their preparation began, and yet various efforts
are devoted to producing more advantageous and
more effective maps.   The experience of
producing Flood Hazard Maps in Japan and TC is
hereupon briefly introduced. The respective
staffs of the local municipalities involved are
highly expected to make their utmost efforts,
with marked enthusiasm, in preparing reliable and
effective Flood Hazard Maps.
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ARIGATO

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• Thank you for your attention!