The Damage Situation of Great East Japan Earthquake in March 2011 and Approach on Disaster Mitigation
Kazutoshi KAN Shibaura Institute of Technology Tokyo, ＪＡＰＡＮ
A massive 9.0 magnitude earthquake was occurred 14:47 on March 11, 2011
Tohoku area
The epicenter
University
A massive 9.0 magnitude earthquake and tsunami hit Eastern Japan on March 11, 2011.
1. Earthquake covers wide area extending 500km along Japan trench and 200km in width Japan trench
A massive 9.0 magnitude earthquake and tsunami hit Eastern Japan on March 11, 2011. 2. Movement of land by 4.4m toward the east 3. Large movement of Pacific Ocean Plate induced huge tsunami 4) Subsidence of land at coastal zone is almost 1.om. Total inundated area are 561km2 5. The maximum height has reached almost 15 to 16m at Iwate and Miyagi prefectures 6. The maximum run-up height was 38.9m
7. The long duration of earthquake caused liquefaction 8. Liquefaction also occurred widely in Kanto Plain where the soil layers are composed of fluvial deposits 9. 15,687 people were killed and 4,757 are still missing 10. Debris and waste caused by tsunami is about 22.6 million tons, and about 60% of them are still on site 11. The number of refugee( including accident of nuclear power plant) are still 87,000.
Huge tsunami occurred at Tohoku area
Tohoku area
Liquefaction occurred at Kanto area Observed points by Prof. Yasuda (â—?)
Kanto area
Urayasu City
University Campus
Disneyland
Damage by liquefaction at Urayasu Urayasu city is famous for Disneyland. 1) The long duration earthquake caused liquefaction. Liquefaction also occurred widely in Kanto Plain where the soil layers are composed of fluvial deposits. 2) The many portion of Urayasu city is reclaimed land, and have a high liquefaction danger. 3) Since our campus was also in reclaimed land, we worried about liquefaction damage. 4) Major infrastructures and many houses in Urayasu city at Chiba were damaged by liquefaction.
Damages were caused almost by tsunami
Liquefaction point at Kanto area which observed by Prof. Yasuda (â—?)
Disneyland
Damage by liquefaction at Urayasu city (Chiba Prefecture)
A massive 9.0 magnitude earthquake and tsunami hit Eastern Japan on March 11, 2011. 1）In just 30 minutes after the quake, large tsunami waves continuously struck the northeastern coastline. 2）Tsunami wave swallowed the flat land and the village in valley near the coastline. 3）The tsunami invaded to the 30 meter height. Many people lost their life and houses. Infrastructures suffered serious damages road, railway, water supply system, etc
Economical damage of tsunami Amount of damage
Building
10.4 trillion yen
A residence and housing site, a store and an office, a factory, a machine Lifeline facilities
1.3 trillion yen
Water service, gas, electricity, communication facilities Infrastructure
2.2 trillion yen
A river, a road, a port, a sewer, an airport Agriculture, forestry, fishery
1.9 trillion yen
Farmland, facility of agriculture, facility of fishery Others
1.1 trillion yen
An education facility, medical care and a welfare relation facility The sum total of the amount of damage
16.9 trillion yen
1) Direct damage sum is about 17～20 trillion yen 2) Indirect damage sum is guessed about 40 trillion yen. 3) Direct damage sum corresponds to about 3.7 % to GDP of Japan.
Debris and waste caused by Tsunami ■ The amount of guess （ x 1000 ton） ■ The amount of carrying in to a temporary place (x 1000 ton)
Killed, Missing, Debris and waste Sept. 16, 2011
Debris and waste is about 22.6 million tons, and 53% of them are still on site
Debris and waste which carrying in to a temporary place Spontaneous combustion by methane generating
Main Purpose of Investigation 1)I investigated urgently to assess the states and mechanisms of damage from the huge tsunami. 2)The investigation were mainly focused to the feature of tsunami as a natural origin of the disaster 3)Assess the effectiveness of the hard structures and nonstructural measures
tide embankment, early-warning system, communication system, evacuation activities
Main Investigation Places Tohoku area
The maximum Run-up height of each tsunami Meiji sanriku earthquake
Showa sanriku
Chile earthquake (1960)
East Japan earthquake
3.0m 13.6m 8.9m 2.4m 1.2m
4.1m 5.8m 5.5m 2.6m
9.2m 35.2m 30.1m 11.0m 9.4m
Earthquake (1933)
(1896)
Hachinohe 3.0m Miyako 18.3m Oofunato 38.2m Sendai Iwaki
inundation depth
I initial sea level
inundation height: I
ground level
R
run-up height: R
Fig.2 Inundation height and Run-up height
(2011)
REASON OF DAMAGE BY BIG TSUNAMI One reason of occurrence of this big tsunami is quick rise of sea level owing to massive 9.0 magnitude earthquake.
The sea level rapidly rose to 6.7m about 30 minutes after the occurrence of earthquake This rapid risen wave is propagated to coastline and wave height gradually increase. High tsunami exceeded the tide embankment and invaded to the urban area.
Height of Tsunami Observed
Aomori
Iwate
Miyagi Fukushima Ibaraki
Chiba
2) Width of earthquake area of 500km is extreme scale 3)Tsunami was amplified by the geographical characteristic
inundation depth
I initial sea level
inundation height: I
ground level
R
run-up height: R
Fig.2 Inundation height and Run-up height
Fig.4 Inundation height, run-up height, wave height
4)The embankment was constructed The big tsunami overflow this tide embankment Many people died and were missing number of dead and missing at Miyako : about 700 persons at Kamaishi : about 1300 at Ofunato : about 500 at Rikuzentakada : about 200 at Kesennuma : about 1400
Fig.5 Number of dead and missing
The ratio of the killed, missing and the evacuated persons was about 1/10.
* many inhabitants live by fishery and agriculture * many inhabitants want to live near a shoreline
Tsunami hit these areas Infrastructures suffered big damages houses, road, railway, water supply system, etc
Damage situation at Kesennuma city
*Kesennuma city is a big fishing port (burned big ship) * Evacuated to the offing with an earthquake occurrence *Most ships suffered the tsunami damage in the port
*Subsidence is occurred by an earthquake, and the inundation occurred in a part of city.
*There was a high place close to a shoreline *Many inhabitants evacuated to these high place . *The tsunami attacked this area and burned one night
Kesennuma City burned one night
Damage situation at Rikuzentakata city
Local leader flush away with tsunami
*Coastline has been protected by tide embankment and pine tree woods (control forest) * Tsunami flushed away these embankment and woods and invaded to urban area
Tsunami passing control forests
Rikuzentakata (Iwate) March 18, 2011
March 12, 2011
*Inundation height reached over 9 m, tsunami overflow the tide embankment and flush away perfectly. *Most houses and building were destroyed and many human damages occurred.
I was able to be heard about evacuated situation from inhabitant of Rikuzentakata. *Experience and learning from past earthquake and tsunami disaster, inhabitant repeated evacuation trainings *the evacuation to the high place has been done in the individual‘s judgment (1)He evacuated to building of high place after earthquake with his family. (2)His group was watching tsunami for 15 minutes. (3) But tsunami not came. (4) Many people returned to the house to take the important one. (5) The tsunami arrived in 30 minutes after the earthquake had occurred. (6)Many human damages occurred.
Damage situation at Minamisanriku town
*Minamisanriku town is located at the small cloughs. *Tsunami run-up height reached to 30 m. * Almost houses were destroyed .
Inundation of land by tsunami, Sendai
Burning houses transported by tsunami Land is inundated by sea water
Damage situation at Natori area
*Natori area is located in the plains part near the Sendai airport.
*The inundation height was not large because of smooth geographical features *Tsunami damage occurred at wide area.
*Tsunami reached even the paddy field and a lot of seawater damaged to the paddy field.
THE EFFECT OF TIDE EMBANKMENT In general speaking
*Tide embankment can be expected to decrease the inundation height. *The decrease of inundation height induce the decrease of inundation depth and run-up height.
*The effect of this embankment helped the evacuation activity, and was able to decrease the damage to a lot of lives and the properties. *The tide embankment was consequentially destroyed by the tsunami overtopping, and a lot of damage occurred.
Design structure of tide embankment
Impact force
sea level tide embankment compacted grains sand
ground level
Big tide embankment at Taro area *Taro area, Iwate prefecture, is a well-known area for its big tide embankment
*In 1896, a tsunami killed 83% of population in Taro area (21,953 people) , and in 1933, tsunami swept and destroyed 90% of town. *Through ancestral history, the coastal locals have taken safety measures against tsunami. * In 1957, a 10 meter height of Meiji- sanriku tsunami, 1896 coastal levee has been completed.
*Big red line indicated the tide embankment constructed by 1957 and height is 10 m. *Small red line indicates the new embankment. Big and high tide embankment have been protect the town area from high tsunami.
Tsunami overtopping 10m high levee at Taro Town, Iwate
Historical Review Continuously struck by tsunamis *Meiji-sanriku tsunami (1896, M8.25) 38.2 m height (run-up height) of tsunami 22,000 people were killed. *Showa-sanriku tsunami (1933, M8.1) recorded 28.7 m height tsunami. 3,064 people were killed. *Chile earthquake (1960, M9.5) 6 m height tsunami. 142 people died.
Long term historical review Huge tsunami occurred with an interval of about 1,000 years Jyogan tsunami (July 13, 869; M8.3～8.6) About 1,000 people were killed (population of Japan was about 6 million). Tsunami reached the local government office located 4～5 km from the coast. It is written in old document(Sandaijitsuki)
Geological Survey Proved *Geological survey of soil layers in Sendai plain proved the content written in Sandaijitsuki. *Further survey has shown on the soil layers in Sendai plain found other two depositional sand layers with several centimeters thickness. *As a result, it is concluded that the area has experienced huge tsunamis at an interval of 800～ 1,100 years.
Depositional Layers produced by huge tsunamis observed at Kesennuma
(Yomiuiri newspaper, Aug. 22, 2011)
Deposition during 6000 years
(Yomiuiri newspaper, Aug. 22, 2011)
Warning made in advance * The researchers warned on July 27, 2009 that a huge tsunami will occur in very near future, since more than 1,100 years has passed from the latest huge tsunami occurred in 869. * They also warned the danger which may occure for the Fukushima dai-ichi nuclear power plant. However, their warning was neglected by the central government and Tokyo Electric Power Company.
Nuclear power plants Two nuclear power plants exist
Two nuclear power plants affected by the tsunami
Onagawa nuclear power plants
Saw-tooth type coastline
Onagawa Nuclear power plants *Onagawa (Tohoku EPCO): Safe Design tsunami height is 9.1m. *the power plant was constructed at the elevation of extraordinary height of 14.8m Tsunami height was 13m Tsunami did not reach the major building of plant *Civil engineer noticed the existence of Jyogan tsunami by old document * The engineer took into account the danger of huge tsunami for the design of Onagawa nuclear power plant
*Water-storage channel prepared could provide cooling water for 40 minutes.
A civil engineer who was very careful for the safety designed Onagawa nuclear power plant
Fukushima Dai-ichi nuclear power plants
*Fukushima Dai-ichi (Tokyo EPCO): Design tsunami height is 5.7m. *the power plant was constructed at the elevation of 10.0m Tsunami height was 13.1m
the facilities including cooling system were inundated This indicated that the engineer have to learn from long term historical review
LAW FOR DISASTER RELIEF ACT Japan has a law for disaster relief act. One is the Disaster Relief Act. A law for a national disaster relief to save citizen's emergency under the support of local government and the cooperation of inhabitants. The concrete activity is carried out based on the request of the local governor.
Disaster help agreements The others are disaster help agreements. It is the help of local government aspect each other, and an agreement between local private company and the local government
Many local engineers were worked based on this agreement from the early stage after the disaster. In addition, Local leader flush away with tsunami , support from other local governments was carried out by based on this agreement. Many NPO, local community , many group supported the restoration from disaster as volunteer
Lessons from big disaster These disaster damage are unparalleled in the modern history of Japan Massive earthquake and tsunami Fukushima dai-ichi nuclear power plant accident
Measures that Japan must take, therefore, need to correspond to the severity of the situation. Our science and technology have to think which way the country must lead
Lessons from big disaster This big disaster is challenged to our established technological knowledge after second world of war *For protection to a big and unpredicted disaster 1)We have to change the concept from complete protection by hard measure to the concept how reduce the human damages and how reduce the damage risk.
2) In designing very important facilities, engineers should take to into account of historical review except for statistical point of view. 3) Decision makers should consider safety fully except for economical point of view for important facilities which might induce catastrophy. 4) Improvement of the early-warning system to the rapid phenomenon are important issues
Lessons learn from big disaster 5) The reinforcement of the disaster adaptation with a lesson from the experience of a past disaster is important It is necessary to make it to the chance to try to think about the usage of the tsunami hazard map, and evacuation drill 6) Risk management for each disaster scale is important. We have to imagine the unpredictable natural disaster situation and discuss the mitigation measure
7)The communication of the intention of the evacuation drill, the evacuation rout, and the hazard map is important. 8)It is necessary to make it to the chance to think about the evacuation activities. Continuing education is very important 9) The reinforcement of tide embankment to the overtopping is necessary.
10) In the early stages of disaster restoration, the humanitarian support by the government, local administration, a bank, the community, and a volunteer played the large role. (11) In the framework of the whole reconstruction assistance, the design of institutional arrangements which guarantees medical support and humanitarian support is required.
(12) The building for refuge is planned in new city planning. Correspondence ability strengthening in soft sides, such as an evacuation route, refuge area, and means of escape, is required
Others (1) In a recovery program, the state of cooperation of city planning and disaster prevention planning needs to be checked. (2)It is required to clarify division of roles of international support and domestic support with globalization of a disaster. (3)An engineer needs construction of the network which can be adapted to any disasters.
(4)Since the technical development for damage mitigation is behind, it adds the viewpoint of risk management, and the viewpoint of residents' disaster adaptation ability strengthening, and research of new technical development is required for it. (5)The role of the volunteer in disaster restoration is large, and it is important to make a chance to train them daily.
(6) The pacific and south east Asia are located on the same climate change influence. (7) Heavy rain and flood disaster occurred in Australia, Thai, Japan and other south east Asia countries. This trend appeared clearly in recent years. (8) Characteristics of disaster in the pacific and south east Asia is similar, therefore it is important to exchange the information and knowledge each other
I would like to express a sincere thanks for the warm encouragement and many supports offered from the people of the world. and
Thank you for your attention