Risk-based land use and spatial planning
Miho OHARA
International Centre for Water Hazards and Risk
Management (ICHARM)
Public Works Research Institute (PWRI), Japan
Under the auspices of UNESCO
Introduction of ICHARM
International Centre for Water Hazards and Risk Management (ICHARM)
was officially established as a UNESCO category II center and a part of the
Public Works Research Institute of Japan on March 6, 2006.
Efficient Information
Networking
Effective Capacity
Building
Innovative Research Flood modeling
and simulation Risk Assessment
Hazard Assessment
Workshop Training Master and PhD students
Risk-based land use and spatial planning
Data & Statistics
Risk Assessment & Risk Identification
Building Social Consensus for Identification of Target Hazard
Land Use and
Spatial Planning
Contribution from
Private Sector
Final Goal: Disaster Risk Reduction
Combination with Other Countermeasures
Understanding from
Citizens
1. Example of Risk-based Approach after the 2011 Great East Japan Earthquake in Japan
-As a consequence of gigantic tsunamis which hit the Pacific coast of Japan, 19,535 people died and 2,585 are still missing as of March 2017.
Two Target Levels of Tsunami
Level 1 Tsunami: Frequent tsunami
Level 2 Tsunami: Largest scale tsunami
Damaged levee due to 2011 tsunami
Adopted by Ministry of Land, Infrastructure, Transport and Tourism (MLIT) and translated by ICHARM
Levee before 2011 tsunami
Levee improved after 2011 tsunami
The height of tsunami at 2011 event
I tegrated easures o i i g structural and non-structural measures.
Land subsidence
Role of National and Local Gover e ts for Build Ba k Better
National Level: Legal framework of Disaster Risk Area by Building Standard Act.
Local government Level: Designation of Disaster Risk Area by ordinances
Relocation Projects for residences to move to safer land.
Evacuation Tower Disaster Risk Area
Outside Disaster Risk Area R
oa
d
Schools, Hospitals, Evacuation space Houses,
Evacuation facility
Ele
vate
d
Ro
ad
Factory, Park
(No house)
Lev
ee
Leve
e
Levee for protecting
Level 1 tsunami Ishinomaki City
Current Status of Relocation to Safer Land
-Relocations are still underway.
-By March, 2017, almost 90% of
the land development for
relocation has been done.
-By March, 2018, it is scheduled
to be completed.
Land Development of Relocation
Adopted by Reconstruction Agency Disaster Risk Area
Act for Tsunami-Resilient Cities (2011)
-A new act for tsunami-resilient cities was enacted in order to reduce tsunami disaster risk in all coastal areas in Japan.
Adopted by Ministry of Land, Infrastructure, Transport and Tourism (MLIT) and translated by ICHARM
2. Example of Practical Approach by Local Government Considering Flood Inundation Probability
-Shiga Prefecture adopted a unique policy for integrated flood management considering flood inundation probability in land use planning.
10 Year Return Period 100 Year Return Period 200 Year Return Period
Laser-scanned Precise Elevation Map High-resolution Inundation Simulation
Precise Flood Inundation Mapping
Adopted by Shiga Prefectural Government and translated by ICHARM
Risk Matrix for Land Use Planning -Shiga Prefe ture is o du ti g la d use pla i g usi g Risk Matrix . La d use is determined according to the inundation probability and inundation level.
https://www.e3s-conferences.org/articles/e3sconf/pdf/2016/02/e3sconf_flood2016_13008.pdf
1/ 2 (0.500)
1/ 10 (0.100)
1/ 30 (0.033)
1/ 50 (0.020)
1/100 (0.010)
1/200 (0.005)
------
Inundation Level
h<0.1m 0.1<h
<0.5m
0.5<h
<3.0m
h>=3.0
m
Inu
nd
atio
n P
rob
ab
ility
If an inundation of over 50 centimeters deep is expected to occur more than once in 10 years, the area will be taken off the list of areas for future urbanization.
If an inundation of over 3 meters deep is expected to occur more than once in 200 years, the area is designated as Flood Risk Zo e, with building regulation.
High Risk
Low Risk
Conclusions National Level
• Legal framework for ensuring sustainability
• Science and technology for risk assessment to identify and
monitor risk
• Building consensus for identification of target hazard level
• Realizatio of Build Ba k Better
Local Government Level
• More risk sensitive land use and spatial planning
• Combination with other countermeasures such as evacuation,
multiple uses of infrastructures, etc.
International Cooperation
• Information sharing of good practices
• Training of engineers and practitioners
http://www.icharm.pwri.go.jp/