Tsunami evacuation mound (“inochiyama” or “mountain of life”)
ENTRY DATE: 26.12.2014 | LAST UPDATE: 26.12.2014
CATEGORIES:
- Disaster Prevention
- Coastal disaster (Hard measures)
TECHNOLOGIES MATURITY:
Being introduced and promoted in Japan.
Technology Owners:
Municipalities all over Japan
Needs Address
Provides a place of refuge, for evacuation from tsunami or storm surge where no high-rise buildings and high ground are available nearby.
Adaptation effects
Evacuation from tsunamis, storm surges.
Overview and Features
- The tsunami evacuation mound is an artificial structure such as a mound, to be used as a refuge from tsunamis.
- In some parts of Japan, dating from approximately 300 years ago, one can find refuge spots known as "inochiyama" (meaning mountain of life), which were built into slightly-elevated mounds as refuge from storm surges. As one of the lessons learned from the Great East Japan Earthquake in 2011, there has been an effort in recent years to have a fresh look at evacuation mounds in various places in Japan as refuges from tsunamis.
Cost
Costs depend on scale. (In the case of the Minato inochiyama in Fukuroi City, on an area of 6,433 square meters, using 1,300 cubic meters of material for the mound, the total construction costs amounted to 215 million yen, of which 114.64 million yen were for construction, 65 million yen for land acquisition, and 7.5 million yen for design.）
Ease of maintenance
Maintenance is about the same as required for a park, with generally no other work required.
Considerations
Unlike the case of vertical tsunami evacuation towers and buildings, this technology requires a large amount of land to be available.
Co-benefit, suitability for developing countries
- Compared to tsunami evacuation towers or other structures, the inochiyama can be constructed at low cost, considering the capacity in number of persons, and can also be used as a park during non-emergency times.
- Compared to structures like a tsunami evacuation tower with a service life of about 50 years, and requiring regular maintenance, the inochiyama is semi-permanent and can accommodate a large number of people.
Information Resources
Fukuroi City, Shizukoka Prefecture (in Japanese)
http://www.city.fukuroi.shizuoka.jp/