2.Research on Tsunami Disaster Prevention
Background and Objectives
Tsunami is a Japanese word which can be divided into two words: tsu and nami. Tsu means harbor; and nami means wave. Tsunami in Japanese thus originally means a giant wave that causes enormous damage in a harbor. A study on tsunami disaster prevention has been an important research topic since the Port and Harbor Research Institute (PHRI) was established in 1962. After the 2004 Indian Ocean tsunami, the Tsunami Research Center (TRC) was founded to study
next-generation tsunami disaster prevention, to prepare for tsunamis due to large-scale earthquakes in the Tokai, Tonankai, and Nankai regions, aiming at no casualties from tsunamis.
The center has been reorganized as the Asia-Pacific Center for Coastal Disaster Research (APaC-CDR) since FY 2010 and studies on preventing coastal disaster are progressing as an important matter.
Research topics
At APaC-CDR, prediction technologies for tsunami disasters and real-time tsunami forecasting technologies as well as technologies for reducing a tsunami’s impact such as a new water gate have been developed.
- Development of disaster prediction technologies
Disaster prevention starts with public awareness of specific actual disaster situations. Thus, we are developing technologies to predict tsunami disasters and enable people to easily understand tsunamis. First, we conduct field surveys
after large tsunami disasters around the world to understand tsunami disasters. We also conduct model experiments to investigate the mechanisms and processes of the disasters in a large-scale flume. Numerical computation programs are being developed to predict disasters. A dynamic tsunami hazard map is also produced from the calculation results for people to easily understand the hazard. Utilizing the calculation and visualization technologies, we have been working on development in planning methods for faster recovery from damages at ports and airports. - Development of innovative non-structural countermeasures
Once an earthquake occurs, a tsunami warning is issued in response to predicting tsunamis based on the seismic epicenter and its magnitude. We are developing new technologies for predicting incident tsunamis to coasts on a real time based on measurement data of tsunamis offshore
by GPS wave meters. - Development of effective structural countermeasures
We are developing a new water gate for tsunamis to effectively reduce tsunami impact.
A new movable water gate for tsunamis is to be
experimented at the site in FY 2011.
Activities in FY 2010
As to disaster caused by the Chilean earthquake tsunami on February 27, 2010, we sent our researchers to Chile asart of a joint field investigation team with the cooperation of other researchers in the earthquake study to clarify the fundamental characteristics of the coastal disaster by the earthquake and tsunami in Chile. For the Indonesian Mentawai earthquake and tsunami on October 25, 2010, we also sent a field investigation team there with the international
cooperation of the Ministry of Marine and Fishery of Indonesia to clarify the fundamental characteristics of the disaster due to the tsunami. In the Great East Japan Earthquake on March 11, 2011, we conducted an urgent field investigation at each of the damaged ports, gathered
information and analyzed the damage. In addition, we have gathered information on 10 tsunamis when tsunami warnings and watches were issued in Japan as well as overseas.
We deliberated on an analysis on destruction phenomena by tsunamis that was experimented on a large scale and on reproducing the disaster with calculation. Then we improved programs to reproduce destruction phenomena in further detail. We structured a combined system with an
individual element method and reproduced how the walls are destroyed.
In order to improve evacuation, an actual evacuation was studied in the field investigation held in FY 2009 and FY 2010. We found securing an emergency evacuation shelter important based on the behavioral principle in the evacuation planning. Such a behavioral principle includes the fact that
people initiate an evacuation only when they actually see tsunami or hear the sound of tsunami.
We conducted a tsunami disaster simulation at Shimizu port in cooperation with the Shimizu Port Office to specifically move forward with port administrators and people who utilize ports, working to develop planning methods to promptly recover from the damage caused by a tsunami disaster.
The real time prediction technology of tsunamis using tsunami data obtained by GPS wave meters has been extended to immediately estimate tsunami inundation areas. In addition, we have developed a technology to estimate inundation areas in approximately several minutes after measurement of the first tsunami peak by the GPY wave meters.
Development of a new tsunami water gate has been studied for an upright floating gate in cooperation with the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) and the private sector to research a (stability of seabed scour) and to deliberate the influences such a gate would provide for its surroundings in FY 2010. From January 26 to 27, 2011, we held the 7th International Workshop on Coastal Disaster Prevention at Shinagawa in Tokyo in cooperation with MLIT and the Coastal Development Institute of Technology (CDIT). Further, we accepted three researchers from Chile through MLIT’s exchange program with research agencies in developing countries and instructed tsunami computation technologies as well as soft and hard countermeasures against tsunamis in Japan. Through these activities, we have been promoting
international cooperation on tsunami disaster prevention in the Asia-Pacific region.
In addition, we hold public lectures on tsunami disaster prevention sponsored by the government and communities in Japan, participate in the committee, and provide support with countermeasure planning against tsunamis in various areas at home as well as overseas through JICA technical
cooperation projects.
