Proceedings of the International Symposium on Engineering Lessons Learned fromthe 2011 Great East Japan Earthquake, March 1-4, 2012, Tokyo, JapanA COMPARATIVE STUDY ON HUMAN IMPACTS
CAUSED BY THE 2011 GREAT EAST JAPAN
EARTHQUAKE AND DISASTER MITIGATION
Nam-Yi YUN1 and Masanori HAMADA2
1

Ph.D. Candidate, Department of Civil and Environmental Engineering, Waseda University,
Tokyo, Japan, namyiyun@toki.waseda.jp
2
Professor, Department of Civil and Environmental Engineering, Waseda University,
Tokyo, Japan, hamada@waseda.jp
ABSTRACT: This study investigates into the relationships of the various factors in theloss of human lives caused by the 2011 Great East Japan Earthquake in March 11, 2011.
A comparative study illustrates the difference between the casualty in Banda Aceh,
Indonesia during the 2004 Indian Ocean Tsunami and several typical affected areas inJapan. In order to elucidate the human impacts, 80,000 witnesses from Tohoku to Kanto
area were analyzed. Therefore, integrated strategies for the reduction of the casualty inlarge-scale natural disasters in the future are proposed in this study.
Key Words: Great East Japan earthquake, disaster mitigation, behavioral perspective,
comparative study

INTRODUCTION
The gigantic earthquake off the Pacific coast of Tohoku, Japan (38.1035°N, 142.861°E, M 9.0 at
14:46:18 JST according to Japan Meteorological Agency) on March 11, 2011 generated a hugetsunami, which caused catastrophic damages in a vast areas of Tohoku and Kanto. The number ofhuman lives reached 15,845 fatalities and 3,380 missing according to an announcement made by the
National Police Agency (January 23rd, 2012)1. The tsunami inundated a large area, and destroyed ahuge number of houses, buildings and infrastructures, such as railways, roads, bridges and quay walls.
The tsunami also severely damaged various lifeline systems, water, sewer, electricity andtelecommunication. The accident at the Fukushima No. 1 nuclear power plant, which was caused by
the earthquake and the tsunami, created the most serious damage and continues to be in a criticalsituation. As many as 50,000 residents within 30 km (19 miles) of the plant have been forced to move
far from the contaminated area. Furthermore, the in the refuge areas is supposed to continue for an
extended time. However, we have to find the future directions to create a safer and more secure society
against future earthquakes and tsunamis based on the lessons from this disaster.

1

The National Police Agency (http://www.npa.go.jp/archive/keibi/biki/higaijokyo.pdf)

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Table 1 Summary of damages in the 2011 Great East Japan Earthquake
Earthquake

Magnitude

The 2011 Great East
Japan Earthquake

9.0

Meiji-Sanriku(Estimated Damage)

8.6

Casualty(Death/Missing)
19,8006,315
11,618
1,843
2,700
2,100
360
60

Inundation
area (㎢)

Areawhole Japan
Iwate Pref.
Miyagi Pref.
Fukushima Pref.
whole Japan
Iwate pre.
Miyagi pre.
Fukushima pre.

561
58
327
112
270
50
60
20

Structure
Damages
113,300
20,20975,391
17,740
9,400
6,400
2,000
300

(Source) [Tohoku district Pacific offing earthquake]
Magnitude: Japanese Meteorological Agency "the 2011 off the Pacific coast of Tohoku Earthquake (15th report)" (2011.3.13)
Inundation area:Geographical Information Authority of Japan"Inundated areas caused by the tsunami (5th report)”(2011,4, 18)
Casualty/Structure damages: National Police Agency “Damage situation and Police Countermeasures associated with 2011
Tohoku district-off the Pacific Ocean Earthquake” (September 26, 2011)[Meiji-Sanriku (Estimated Damage)]
Magnitude: Trench-type earthquakes around Japan Trench∙Kuril Trench (H18.1.25), p67, (calculated value from a fault
model)
Inundation area: the assumed value for assumption damage from the Meji-Sanriku type earthquake with dikes
Casualty/Structure damages: Specialized investigation committee for Trench-type earthquakes around Japan Trench∙Kuril
Trench (January 25, 2006), p 55, p 57

HUMAN IMPACTS OF THE DISASTER
The escalation of natural disasters in 2011 brought many concerns with Japan’s earthquake which wasan unprecedented event. However, the loss of humans as a result of earthquakes is avoidable andpreventable. A mitigation of deaths and injuries is of a primary concern to all disaster prevention
efforts2. The focus of the present study is on the death tolls of human lives because of the huge numberof death in wide inundated areas (56 ㎢, 6 prefectures, 62 cities)3 is still in an ongoing classification.
Cause of death
The earthquake triggered powerful tsunami waves that caused extensive and severe damages in Japan.
Of the 13,135 fatalities recovered by 11 April 2011, 92.5% died by drowning and others were caused
by non-tsunami reasons, like being crushed or injured, and by fire4.
Table 2 Cause of death
Cause of Death

NumberDrowning

12,143

92.4%

Crushing, Injury

578

4.4%

Fire

148

1.1%

Unknown266

2.0%

13,135

100%

Total
2

Percentage

Earthquake Casualties Research and Public Education, M. Petal
Geospatial Information Authority of Japan (http://www.gsi.go.jp/common/000059939.pdf)
4
Asahi newspaper (http://www.asahi.com/special/10005/TKY201104190477.html)
3

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Across twelve prefectures, the earthquake and tsunami left enormous damages to wide area.
Table 3 Damages breakdown by twelve prefectures5
Prefecture

Death

Missing

Complete
destruction

Hokkaido

100

Aomori

3

1

307

Iwate

4,665

1,383

20,209Miyagi

9,505

1,878

75,391

Yamagata

2

037

Fukushima

1,605

220

17,740

Tokyo

7

0

0

Ibaraki

24

1

2,799

4
1
20
4
15,841

0

262
0
797
0
117,542

Tochigi
Gunma
Chiba
Kanagawa
Total

2
0
3,485

City
(Prefecture)
Kamaishi(Iwate)Rikuzentakada(Iwate)Ofunato(Iwate)Kesennuma(Miyagi)
Ishinomaki(Miyagi)
Onagawa-cho(Miyagi)
Matsushima(Miyagi)
Soma(Fukushima)

Rate of
Casualty

Casualty
NumberPopulationof 2010

2.78%

1,091

39,508

8.37%

1,951

23,302

1.11%

452

40,738

1.89%

1,407

74,247

2.44%

3,927

160,704

9.70%

975

10,0510.01%

215,0891.21%

459

37,796Regarding the age of the victims6 in the affected three (Iwate, Miyagi, Fukushima) prefectures,
24.0% were 70-79 years old, 22.1% were more than 80 years old, and 19.1% were between 60-69
years old. Victims aged 60 or older accounted for 65.2% of the deaths with 45.5% of total victims
being men and 53.6% female.
MENTIONED CAUSES OF HUGE DAMAGES
According to The Central Disaster Management Council, this devastating effect has resulted fromthree aspects: unprecedented wide range and magnitude, unexpected scale of the earthquake, and thetsunami heights that significantly exceeded the expected height.
Inaccurate Prediction for future earthquakes
Before the occurrence of the 2011 Great East Japan earthquake, the Central Council of Japan for
Disaster Prevention had been warning about five big earthquakes, which have a high probability ofoccurring in near future and may cause a serious damage. Among these earthquakes, the magnitude ofthe earthquake at Off-Miyagi Prefecture was estimated as a medium size earthquake of magnitude 7.5.
However, the magnitude of the actual event was 9.0, that is 180 times larger than the predictedearthquake. Even though the prediction was inaccurate, we would not have known what sort ofearthquake could happen.

5

http://www.bousai.go.jp/jishin/chubou/higashinihon/12/3.pdf
Until 11th April, 2011, the National Police Agency confirmed and announced cause in the 13,135 deaths. In prefectures of
Iwate/Miyagi/Fukushima, the analysis by age: Cabinet Office in Ministry of Internal Affairs and Communications.
6

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Tsunami is rare event with extreme consequence
Unfortunately, the tsunami wave height falls into the category of an unexpected and extraordinary
curve since the earthquake occurred7. In addition, tsunami has different waves that repeat itself manytimes. The first wave of a tsunami is not always the drawback wave, but can be the run-up wave.
Moreover, the second, third or subsequent waves can, in some cases, be bigger than the initial wave.
Due to the characteristics of the tsunami, a threshold return period exists and the expected tsunami
wave height and times are insignificant.
COMPARATIVE STUDY: THE 2004 INDIAN OCEAN EARTHQUAKEAs the 2011 Great East Japan Earthquake tragically demonstrated a rare and extreme tsunami eventthat might have caused thousands of fatalities. In the Indian Ocean Earthquake Mw 9.3 on December
26, 2004, the tsunami devastated shores of the Indian Ocean. The number of victims, dead and missing
together, is estimated 230,0008. Many researches and media mentioned the impacts and scenes of theabove two disasters are similar to one another. While each disaster is unique to its time and place, theprocess of its recovery, reconstruction, and preventive steps against future disasters have someresemblance to each other. Therefore, cross national and comparative studies provide a lens into themechanisms used to understand, manipulate, or evaluate them in disaster consequences and its
recovery. In addition, post-disaster behavior and institutions are often a function of pre-disastercondition. It can help the researcher ascend from the initial level of exploratory case studies to a moreadvanced level of general theoretical models and invariances, such as causality or evolution. Whether
quantitative or qualitative, comparative analysis allows us to explain the variation through the cases
providing patterns that suggest the course of future events based on the past ones. In this chapter, an
ongoing research, comparing disasters in India and Japan, show how comparative analysis can provide
insight and improve our understanding of natural disasters. In Japan from the 2011 disaster, rubble is
4.5 times more than the 10,000,000m³ in India, and is 1.8 times more than the 15 million tonnes of
wreckage from the 1995 Kobe earthquake.
Table 4 Comparative Study: the 2004 Indian Ocean Tsunami
2011 Tōhoku
earthquake and tsunami

Damages

Death: 15,841 / Missing: 3,485 /Injured: 5,894

Death: 127,707/ Missing: 93,285 (in 2004)

Collapse

Totally: 78,641 / Half: 30,278 /Partially damages: 240,378/
Non-dwelling: 25,987

Burn down

Totally and Partially: 260

Swept out-

249,190(small/medium businesses:104,500/
Houses: 139,000 /Worship places: 1,089 /School facilities: 3,415 /Health facilities: 517 /Government buildings: 669)

Inundated

Above floor level: 4,222 /Below: 4,435-

Roads: 3,970 / Bridges: 71/ Railways: 26

Kilometers of road destroyed: 2,618 /Bridges: 119 / Railways and Airports: 8

Human

Housings
andBuildings

Bridges

2004 Indian and 2005 Nias
earthquake and tsunami97Death: 979(850 in Nias) / Injured: 11,579

On Tsunami Risk Assessment for the West Coast of Thailand (Farrokh Nadim & Thomas Glade,2006) ECI Conference on
Geohazards
8International Federation of Red Cross and Red Crescent Societies, World Disasters Report. (Kumarian Press), 2005, 246 p.
9
Source: SERI BUKU BRR

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Embankments/ Landslides

Break of dikes: 4/ Landslides: 184

Ports destroyed: 22

Tsunami Waste

27million ton=45,762,711m³(10*average 0.59 t/m³)

400,000 m³ (max: 10,000,000 m³)

On March 21st, the World Bank estimated that Japan’s massive earthquake and tsunami could costits economy up to $235 billion, or four percent of output with reconstruction that could take five years.
By contrast, the damage resulting from the 1995 temblor totaled around 10 trillion yen. Hyogo
prefecture, which took a big hit, accounted for about four percent of the nation’s total output at thetime. But, the prefectures of Aomori, Iwate, Miyagi, Fukushima and Ibaraki, which bore the brunt of
the recent quake, make up roughly seven percent of national output, leaving a larger mark on theoverall domestic economy. Moreover, a heavy concentration of parts and materials manufacturers
make their home in northeastern Japan and other disaster-stricken areas closer to Tokyo, resulting inshortage of supplies to a wide range of industries.
Table 5 Comparative Study: the 1995 Kobe earthquake

DamageDeath toll
Cost to private insurance
National budget for reconst
ructionThe 2011 Great East Japan
Earthquake$122 to 235 billion(2.5 to 4 percent of GDP)

$100 billion(around 2 percent of GDP)

15,214 (dead and mission)

6,434

The 1995 Kobe earthquake$14-33 billion*$783 million*Note: AIR World estimate$12 billion from current budget
much more FY 2011$38 billion over 2 fiscal years

Shown in Table 6, recoveries came despite the different levels of domestic and international aid toindividuals, families, and businesses. It reveals that although Tamil Nadu was the poorest of the three,
its business, shops, and housing rebounded with more resilience than New Orleans. Furthermore,
Kobe did quite well despite immense damage, both in terms of deaths (6,500, the highest of thesethree) and property damage ($ 180 billion, the highest again).
Table 6 One year after the disaster
Case

Business Sector

Shops / Schools

Housing

Kobe, Japan

80% experts, 90%
manufacturing restored

80% shops, majority ofschools reopened

Close to 85%
in permanent housing

Tamil Nadu,
India

Almost all fishermen backat work

Old schools rebuilt,
new schools created

50% housing restored

New Orleans,
LA

Unemployment at double
the national average

50% schools, 40% of
shops rebuilt

100,000 households in trailers

Tohoku,Japan1124% Agriculture, 66% ofFisher ports restored

Industrial Production Index:
86.5 in affected areas (before disaster: 96.9) /90.4 in other (97.9)

68% of tsunami waste rem
oved. 52,182 households in
temporary houses(678 in shelter)

10
11

Inoue et al. (2007) estimated debris volume/weight: an average specific gravity of 0.59 t/m³ during transportation.
METI announced (http://www.reconstruction.go.jp/topics/120116_sashikae%28data%29.pdf)

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DISASTER MITIGATION STRATEGY
The past decade has shown an increase in the severity of natural disasters: during the period in 2004
–2007, nine earthquakes of magnitude 8 or greater occurred in the Indian and Pacific Oceans. All ofthese natural disasters generated tsunami in which six were large enough to cause damages. While it is
impossible to prevent a natural disaster from occurring, risk of damages can be prevented or reduced.
This indicates that the human behavior plays a significant role in natural disaster preparedness, as well
as structural and non-structural efforts.
Disaster mitigation
Mitigation plans form the foundation for a community's long-term strategy to reduce disaster losses
and break the cycle of disaster damage, reconstruction, and repeated damage. Hamada and Yun (2011)
stated the following measures and researcher should be strongly promoted: a) survey on traces ofhistorical tsunamis in the world from geological view point, b) establishment of information gatheringand transfer system to grasp the situation of wide spread tsunami-hit areas, c) research on tsunami
resistant buildings and infrastructures, d) town planning to strengthen the tsunami resistance(evacuation, construction tsunami resistant buildings, selection of residential areas, etc.), e) relief
activity immediately after the disaster (evacuation warning, tsunami warning), f) enforcement ofresistance of lifeline systems and quick recovery, and g) Disaster education and training.
 Structural mitigation (Hardware-side efforts): structural safety measures by constructing
facilities for disaster prevention. For example, strengthening buildings and infrastructure
exposed to hazards by means of building codes, engineering design, and construction practices
to increase the resilience and damage resistance of the structures, as well as building
protective structures such as dams, levees and seawalls
 Nonstructural mitigation (Software-side efforts): avoiding hazardous areas by directing new
developments away from the known risky locations (e.g. hazard maps). This can be done
through land use plans and regulations; in addition, relocate the developments with existingdamages to safe areas following a disaster. Public education can emphasize knowledge andskills to help identify items that can slide and fall, to secure tall and heavy furniture,electronics and appliances, to keep exit pathways clear, fasten hanging objects, store heavy
objects lower down, place beds away from windows, and use tempered glass.
In order to minimize the damages from a large-scale disaster, structural and non-structural measures
should be considered and implemented. Moreover, based on the results of post-disaster surveys,
human behavior plays a significant role in natural disaster preparedness, as well as structural andnon-structural efforts.
 Behaviors on evacuation: response skills and provisions against disasters. In spite of tsunami
warning system in Japan, people experiencing the disaster showed unexpected responses.
According to Weathernews survey, only 11% of people immediately evacuated from theaffected coastal areas. Moreover, Cabinet Office in Japan commented that it is necessary toreview assigned evacuation buildings and locations to see whether they are suitable for people.
The damage of the Great East Japan Earthquake is still being adequately investigated and analyzed,
and improvements will be made. In addition, three efforts should merge together to find linkages
between them. Furthermore, key variables will be examined for quantitatively assessing theeffectiveness of promoting disaster management measures.
Structural investigation
Much of works on infrastructure in disaster focused on understanding the mechanics of how
components of infrastructure systems (e.g., bridge piers) perform when subject to extreme forces orconditions. According to the investigation report from the Japan Bridge Association (JBA), 190
bridges (6%, higher than I level) of total 3,004 targeted ones were clarified to need some treatment for1671

trafficability (走行性), and 299 bridges (10%, over than B level) were judged of necessary repairs forload resistant capacity (耐荷性)12. Moreover, most wooden houses on the flat affected area wereentirely flooded. Reinforced concrete (RC) buildings were damaged, but it did not collapse. Also, anumber of destroyed vehicles, ships, and houses were observed to be floating out on the road13.
Some of buildings and concrete bridges which located in the tsunami inundated area survived from thetsunami attack as shown in Figure 1. The concrete building shown in Figure 1 has a five-story, and thefifth floor was flooded. In other words, the water flew through the whole building. However, any
structural damage to the super structure and concrete piles foundation was not found.

Figure 1 Survived a Five-story Concrete Buildingat Rikuzentakada, Iwate Prefecture in Japan(2011)

Figure 2 Survived the Baiturrahman Mosque,Banda Aceh in Indonesia (2004)

Same thing was observed in Banda Ache of Indonesia during the 2004 Indian Ocean Tsunami. Figure
2 shows a survived mosque from the tsunami, which located along the shoreline. The examples ofsurvived buildings shown in Figure 1 and Figure 2 suggest us a possibility of the construction of
concrete buildings which can withstand tsunami attack. Then, when those kinds of characters apply tolarger and taller building along the shoreline, the building can be a safe haven for evacuees fromtsunami. Moreover, lots of bridges survived the tsunami as shown Figure 3. This bridge wasconstructed by steel girders with concrete slab for a road. The tsunami exceeded the bridge’s height,
but no structural damage was observed. Same thing was reported from the Indonesia in 2004. A
concrete bridge in Band Ache shown in Figure 4 is also entirely survived from the tsunami. Thisbridge has concrete shear keys to prevent lateral movements of the girder, which might resist tsunami
force. The examples shown in Figure 3 and Figure 4 also give us some insights into the possibility of
the construction of bridges against tsunami.

Figure 3 Survived the Bridge in Japan (2011)12
13

Figure 4 Survived the Concrete Bridge at Banda
Aceh in Indonesia (2004)

http://www.jasbc.or.jp/images/imageparts/title/release/ppt/2011/H23_0_1.pdf
http://www.pari.go.jp/en/files/items/3496/File/20110325.pdf

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Non-structural investigation
Tsunami Warning System
The Japanese Tsunami Warning Center established back in 1952 and is being maintained by the Japan
Meteorological Agency (JMA). The agency operates about 187 14 seismic stations, 42 real-timeobservations, and monitors the water level stations 15 . On March 11, 2011, JMA provided theinformation, within three minutes after the earthquake had occurred, to all the areas that were
expecting severe treat. To maximize the time for evacuation, the first warning was released quickly16.
28 minutes later, the second report was announced with the expected height of the tsunami being morethan 10 meters. Table 7 shows the tsunami warning system operation.
Table 7 Tsunami Warning Situation in Kesennuma city on March 11, 201117
Time

Contents

Remarks

14:46

Earthquake occurred (Japanese Seismic intensity, 震度６弱)

14:46

Power in the government office and whole city was out

14:48

Radio announcement from disaster prevention: "There isrisk of tsunami, evacuate to the higher place"

14:49

JMA announced big-tsunami warning

14:52

Evacuation commands to citizens by radio announcementfrom disaster prevention

15:00

6 meter of big-tsunami alarm is officially announced

15:20
15:24
15:30
16:35

JMA announced alarm of big-tsunami with more than 10
meter
Miyagi Prefecture identified tsunami of 10 m or more, at 15:14
evacuation command announced
Oil tank outflew. Black smoke started from behind the country
government office building(国合同庁舎)
200 people evacuated to the prefectural government officebuilding (県合同庁舎)

Disaster Response & Recovery
Headquarters was established

Arrival expectation: 6m of tsunami in theprefecture would reach around 15:00
Approximately 30 times of evacuationcommand announced

120 people evacuated to the country
government office building(国合同庁舎)

17:40

Magnitude is revised to 8.8

17:50

Fire at sea occurred

19:13

People evacuated to the roof of the central community center(1st floor was flooded) and to Yayoi food company

450 people in central community center,
400 people in Yayoi food company

22:09

Evacuated to the roof of Mukainada Senior High School

49 people evacuatedDisaster prevention training
Ministry of Education, Culture, Sports, Science and Technology (MEXT) has been developed disastereducation to foster the viability with three major efforts: effort in nation, effort in the community, andeffort in school. From 2008 to 2010, it conducted a project to support regional disaster education
business that is consist of (1) writing disaster reduction-related materials, (2) design training andeducation curriculum development for school staff including teacher, and (3) development morepractical disaster education programs. According to survey (Kamaishi’s shelters), 21% of respondents(total: 322) answered the experiences of disaster education and drill18.
14

http://www.jma.go.jp/jma/press/1110/07a/tsunami-kansoku.pdf (184 →187, JMA released in October 7, 2011)
http://nowphas.mlit.go.jp/index_eng.html
16
http://www.bousai.go.jp/jishin/chubou/higashinihon/1/2.pdf
17
http://www.fdma.go.jp/disaster/chiikibousai_kento/houkokusyo/sanko-2-2-1.pdf
18
Ministry of Land, Infrastructure, Transport and Tourism (2011.7.6）
15

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Kamaishi city: education for children
Since 2005, Kamaishi has been implementing training sessions with active cooperation by Professor
Katada in Gunma University. Its slogan is “safety of the children.” Three evacuation principles for thedisaster prevention training are the following: (1) do not trust unquestioningly in any experience andassumption, (2) do your best under the situation, (3) take the lead and encourage evacuation. As theresult, 5 out of 3,244 children are victims (survival rate: 99.8%) while the casualty is nearly 1,000 in
Kamaishi. Even though it has been introduced as “a miracle of Kamaishi,” the staffs mentioned it is
not just a miracle. It was an accomplishment of disaster prevention efforts.
Education in Kesennuma city
Kesennuma city delivers the education under the slogan "disaster mitigation by self-act and help one
another." The city developed a program and its material while considering age, curriculum, andlocation etc. In order to enforce how to effectively react to the disasters, the city conducts disasterprevention workshops and lectures for the public and elementary schools. Roughly 30 hours per year
are allotted for disaster prevention education at school. Lower grades levels are connected to theregional upper grades that are in charge of leading the lower grades during disasters. Therefore, twelveout of 6,054 students are victims by this disaster.
Behavior of evacuation
Residents’ disaster preparedness capabilities need to be enhanced and combined with other structuraland non-structural aspects. Evacuation actions taken by residents are fundamental to human damage
mitigation measures against disaster. For example, the initial step in protecting human lives from atsunami is evacuating to a higher ground swiftly and autonomously, without hesitation, as soon as astrong or an extended shaking is felt.
Although the engineering effects of the earthquakes within the individual buildings have been
extensively studied in recent years, little work has been done in documenting precisely how people
behave during an earthquake. More detailed information is needed because knowledge of what people
do during and immediately after a severe earthquake can assist researchers in giving advice andtraining residents on how to act in ways that will reduce panic, injury or death in future events.
Studies of residents’ behaviors in the 2011 Great East Japan Earthquake
Using a questionnaire designed to grasp the relationship between evacuation behaviors and tsunami
damages, the investigators interviewed 870 refugees from Iwate, Miyagi, and Fukushima prefecture.
Then, they analyzed their behaviors (Joint investigation by JMA, Fire and Disaster Management
Agency, and Cabinet Office of Japan)19. The results revealed that among 496 immediate evacuees and267 delayed evacuees, 48 percent said they instinctively knew a big tsunami could come after this kindof shaking. 35 percent of evacuees were motivated to evacuate due to the appeals from people aroundthem such as their family (20%) and neighbor (15%). Lastly, 16 percent evacuated because of thetsunami alarms warning. On the other hand, 31 percent of the evacuees, after some hesitation, and 11
percent of respondents, who did not evacuate, were not able to withdraw immediately. The 34 percent
went back to their house to look for or pick up family members. Moreover, 11 percent believed that itwas not possible for a big tsunami to come to their area, given the past experiences, or other reasons,like due to the strong breakwaters. However, the survey illustrated a worst case scenario. The
evacuation led the some hesitant evacuees to go to an undesignated location or to the upper floors of
the same building. Moreover, 57 percent of them evacuated using their cars; and more than one thirdof their cars were in congestion.
19

Survey participants: 870 refugees who have been in Iwate, Miyagi, and the coastal area of Fukushima prefecture (Iwate:391, Miyagi: 385, Fukushima: 94) / Research method: visiting the temporary housing (dwelling) /shelters and conducting
interview face to face (bring the questionnaires and write the answers / Period: from early July by the end of July, 9:00 am 6:00 pm, 30 minutes to 60 minutes per a person

1674Previous researches
This is an overview of the tsunami in Japan since 1980. Twenty eight times of alarms were released;
and four out of those alarms were for tsunami with more than 3 meters. Table 8 illustrates the detailsof the four big tsunamis that were announced along with the earthquake, as well as its results of the
conducted surveys from the affected residents.
Table 8 Comparative Study: Evacuation behaviors during earthquake and tsunami
Name ofthe earthquake

Middle Japan Sea
Earthquake

Hokkaido-NanseiOki Earthquake

Middle part coast
earthquake in Chile

2011

Time of occurrence
Magnitude
Tsunami warning
Max tsunami height(place)Number of Fatalities
and missing
Investigation place(the number of thesamples)
Evacuation Rate (%)

1983.5.26 11:59
7.7
Big tsunami

1993.7.12 22:17
7.8
Big tsunami

2010.2.27 15:34
8.8(*1)
Big tsunami

2011.3.11 14:46
9.0
Big tsunami

1.94m (Noshirokou)

1.75m and more (Esashi)

1.28m (Susakikou)

9.3m (Soma)

104

230

0

Opportunity ofevacuation

Reason of notevacuating

Issues on evacuation

Noshiroshi (1,000)

Okushirichou (204)

3.6%

89.2%
1. Experience of Middle
Japan Sea Earthquake(50.5%)
2. Appeal from the family(39.0%)
3. Appeal from relative,
neighborhood (19.8%)--

Approximately 40% of
the people who heard atsunami warning(54.2%) replied thatsuch a big tsunami
would never come
here.

-

The obtained ratio of
information evacuation
was low (18.1%), but
approximately 80% of
people evacuated before
tsunami arrival because of
the experience of 1983
Middle Japan Sea
Earthquake.

36 cities&village in Aomori& Iwate & Miyagi pre.(5000)
37.5%
1. Appeal from the cities andtowns (47.1%)
2. Experience of 1980 Chile
earthquake and tsunami(44.0%)
3. Big-tsunami alarm (41.3%)
1. Thought that place would
never be inundated fromtsunami (52.7%)
2. The tsunami height of otherarea was not high (19.2%)
3. There was big-tsunami
alarm, but they thought only
the tsunami smaller than 3m(16.5%)In spite of a remote placeearthquake, lifeline andwell-functioned
communication infrastructure,evacuation rate remained injust 37.5%.

19,225870 (3 Prefectures:
Iwate/Miyagi/Fukushima
Prefecture)57%
1. Instinctive thought thattsunami will come after
such a big shaking (48%).
2. Appeal of family,
neighborhood (20%)
3. Hear or see big- tsunami
warning (16%)
1. Go back home (22%)
2. Look for or go to meetfamily (21%)
3. Check their family’s
safety (13%)
Compared to theevacuation rate in 1993,
the rate in 2011 isrelatively low. Based on
surveys in 2006 and 2007,
the evacuation rate in 2006
was nearly half (46.7%)
and one in 2007 was
31.8%. Likewise, despite a
big tsunami alarm in 2010,
the real wave was lesser
than expectation. One year
later, the big-tsunami
alarm might remind of thelast insignificant tsunami.

In particular, the evacuation rate in 1993 was 89.2% compared to the rate in 2011, which was
relatively low at 57%. Considering the results from surveys in 2006 and 2007, the evacuation rate in2006 was nearly half (46.7%) the one in 2007 (31.8%). The reason why they did not evacuate in 2007
was because the tsunami in 2006 was not insignificantly big. It was smaller than estimated height(more than 3m). Likewise, although there was a big tsunami alarm in 2010, the actual wave was lessthan the announced height. Approximately one year later, the same big tsunami alarm might havereminded people of the last trivial details of the tsunami height. Therefore, this was one of the reasons
why they did not evacuate.

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Data from Weather news
From March 14, 2011 to May 10, 2011, information were gathered from 88,604 witnesses fromTohoku (9,136 near the coast of Aomori/Iwate/Miyagi/Akita/Yamagata/Fukushima prefectures) to
Kanto area. Seventeen-question questionnaire consists of time to learn about the tsunami andearthquake, method (e.g., TV, radio), behaviors during the event, and two open-ended questions.
Weathernews, specializing in dealing with disaster data, conducted surveys and collected the datausing the internet and mobile web sites called “Weather Widget”, a smart phone application.
Methodology
The collected open-ended questions in the surveys inform us with valuable information. This study
used text mining for big data analysis. Text mining, also known as text data mining or knowledge
discovery from textual databases, generally refers to the process of extracting interesting andnon-trivial patterns or knowledge from unstructured text documents. Some scholars argue that human
discourse and action can be better explained through qualitative methods instead of natural sciences.
Miles and Huberman20 (1994) stated: “With qualitative data one can preserve chronological flow, seeprecisely which events led to which consequences, and derive fruitful explanations… Words,
especially organized into incidents or stories, have a concrete, vivid, meaningful flavor that often
proves far more convincing to a reader – another researcher, a policy maker, a practitioner – thanpages of summarized numbers.” (p.1) For example, Adam and Muraki analyzed 250 Twitter users’
text-based posts of up to 140 characters, known as tweets, which included the word `earthquake` onMarch 11, 2011. Through a qualitative analysis of the tweets and open-ended responses, the authors
found most of the tweets in the devastated areas were about (a) warnings, (b) help requests, and (c)reports about the environment (tsunami, fire and communication) and themselves.
More than thousands of data are desired as target documents (corpus) when using text mining foranalysis purposes. Therefore, using Weathernews' low data and the number of target documents areenough in this study. The four steps of analyzing the documents for this study is the following: (1)Select key words for two groups, (2) sort the comments into two groups, (3) run statistical analysis(e.g., cross-tabulation analysis or cluster analysis).
Research Questions
Since the past studies do not provide any qualitative assessments on how people proceed to behave
during the disaster, two research questions are: a) what kind of messages did they post about theearthquake? b) two groups (the death/missing, the survivors) show significant differences on behavior
during disasters?
First, we qualitatively analyzed the comments sent from Tohoku area. To analyze, we ran a text
mining tool in Japanese, MeCab and RMeCab, with selected key words `missing`, `corpse`, `deadbody` for a group of the death/missing21. Here are some of the comments from the results of MeCab.
・There were 42 refugees and two employees of the local government on the roof of town
municipal office. Because of the disaster prevention radio announcement (female staff who
was broadcasting is missing), it was able to know the quick invasion of tsunami. Despite badweather, tsunami, and aftershocks, there were encouragements among refugees each other.
When all of family met again, tears did not stop.
・Grandparent picked up their grandchild from kindergarten then went back to house to getluggage. They left the grandson in the car and the tsunami swept out them.

The following table illustrates an example of the results from data based on the Japanese words, its
translation into English, and the frequency of the words.
20
21

Miles, M.B. and Huberman, A.M. (1994) Qualitative Data Analysis, 2nd ed., Sage, Thousand Oakes.
In Japanese, (行方)不明, 死体, 遺体1676

Word in Japanese
行方不明
助かる
遺体
家族
近所

Word in English
Missing person
Be saved or be helpful
Dead body
FamilyNeighborhood

Frequency of word
98
1,091
22
4,506
3,050

It is quite difficult to interpret Japanese words when using text mining tool, even with simple
word’s meaning definition. For example, depending on the sentence, the word `助かる` was translated
into two meanings, (1) be saved and (2) be helpful. With its definition written as `be saved`, it could bea suitable target document. On the other hand, `be helpful` is usually used for just describing thesituation. Therefore, it is necessary to consider how to classify meaningful comments for the analysis.
Gather key words and key sentences
In order to figure out and classify meaningful sentences, it was difficult to extract from the first
Weathernews data. Many of the comments did not contain any actions and expressions of various
emotions. 89.8 % of the comments were reporting about the self or the environment, one percent of thecomments were concerns and condolences, two percent of the data were expressed thank for helping
and for being saved them/their family to God. Negative behaviors included comments were 3.5 % of
the target data and positive behavior ones were 3.7 percent. There, this study analyzed the selected 107
comments regarding death or missing people in the five prefectures (Miyagi 74, Iwate 18, Fukushima
9, Ibaraki 4, Chiba 2). These comments were from the witnesses, which was conducted by
Weathernews within the survey period from May 18, 2011 to June 12, 2011. Here are some comments:
・Fire fighter passed away. He went to close the floodgates, but the gate entirely disappearedwith him. (30-39 years old man, Rikuzentakada, Iwate prefecture)・Appeal for evacuation to neighborhood, but he could not evacuate himself. (60 years oldman, Ishinomaki, Miyagi prefecture)
Result: Ranking of behaviors
In this study, negative behaviors are defined as someone who had that action in which it led to his/her
death. Otherwise, it means that people had positive behaviors. Some comments expressed both
positive and negative behaviors. Therefore, 183 meaningful words and/or sentences were extracted
from the comments by an expert in this field, and classified the comments into groups of negative
behaviors, positive behaviors, reporting self/environment, concern and condolences, and thank topeople or God. In addition, the MeCab and RMeCab were run with the chosen words. As a result, thefrequencies of the each of the behaviors create groups (clusters) according to the definition. The
following Table 9 and Table 10 summarize the ranks of the negative and positive behaviors based on
the frequency of those behaviors.
Table 9 Ranking of the negative behaviors
Rank
1
2
3
4
5
6
7

Behavior
Be tied up on the road traffic jam
Help other people
Do work and duty for rescue
Do not evacuate due to no/wrong information
Find their family/relatives
Ignore the warning based on the past experiences
Leave from the assigned place

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Frequency
26.3%
22.4%
13.9%
13.7%
9.7%
8.9%
5.1%

Table 10 Ranking of the positive behaviors
Rank
1
2
3

Behavior
Immediate Evacuate
Follow other people direction
Remember former disasters

Frequency
52.5%
39.4%
8.1%

Based on Table 10, it is clear that early evacuation is vital for safe state from tsunamis. Moreover,some people who were not expecting a tsunami managed to evacuate as a result of having been
verbally warned by those around them. Therefore, it is crucial for residents who could be affected bytsunamis to understand the importance of early evacuation. Although tsunami warning was announced,
shown in Table 9, many people who were in plains did not have time to evacuate to higher ground.
There were also cases of people losing their lives due to failing to perform necessary evacuation
behaviors. Furthermore, it is important staying in safe and assigned places as well. Figure 5 presents
the number of people in refuge, which shows the people’s behaviors during the 2010 Chile earthquake.
After tsunami alarms, people relocated in refuge, but the number of people in refuge declined overtime. Lots of people came back home while the tsunami warning was still coming out. They went backto their houses before the tsunami completely came to an end. However, Table 9 illustrates thosenegative behavior led to his/her irreversible risk.
３rd
６th

─ ＝measured values＝theoretical values ■＝Number of people in refuge

Figure 5 Number of people in refuge during the 2010 Chile Earthquake (M: 8.8)
Shinmeisaki(神明崎東) in Kesennuma city (気仙沼市), Miyagi Prefecture (宮城県)
Table 11 shows the applied result of the 5,298 data (including 1,998 for the death/missing people)
from Tohoku area by Weathernews.
Table 11 Sort the data into two groups based on the behavior types
Behavior

Negative Behaviors

Positive Behaviors

Total

The Death/Missing

1,543

455

1,998

The Survivor

1,711

1,587

3,298

Total

3,254

2,042

5,296

Group

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In order to verify the significant difference, the cross-tabulation analysis (or cluster analysis) was used,
and the results are shown below in Table 12. The difference of behaviors between group of thedeath/missing and the survivor is significantly distinguished.
Table 12 Sort the data into two groups based on the behavior types
Analysis

Statistic

Analysis

Person χ²

Degrees of freedom

P value2.868

10.090*

CONCLUSION
Full preparation need to be made against earthquake and tsunami since earthquake can occur anywherein Japan. For the huge disasters, it is clear that the different approach in necessary. Instead ofprotecting against any loss of live, trying to save as many lives as possible becomes the mostimportant goal. Based on the prediction for future earthquakes, countermeasures for Tokyo inland
earthquakes will need to examine the earthquake hazard of the size of the 1923 Great Kanto
earthquake. First thing which we have to do is to carefully grasp the whole aspect of the disaster and todeliver the exact information to the researchers in the seismological and earthquake engineering allover the world. It is important to communicate to the international community correct information on
safety and security. Also, investigation reports of impacts of this catastrophic disaster will provide topeople around world. Second thing is to investigate into study on the causes of the disaster. It isnecessary to study what are the differences between the causes of the 2011 East Japan earthquake fromthe previous ones. Moreover, although tsunami warning was announced, many people who were inplains did not have time to evacuate to higher ground. There were also cases of people losing theirlives due to traffic jam. It is necessary to consider a smooth evacuation way using car. Moreover,instead of relying on hardware approach such as improving and strengthening buildings, the disasterprevention puts emphasis on software approach such as improvements to warning systems and morethorough evacuation education. The following future researches are now in progress: (a) role of social
network and ties have explained speed of rescue during disasters and of recovery after disaster. For
example, the twitters’ users retreated messages to call for help in Kessennuma city, then they could
rescued by helicopter, (b) it is necessary to modify guidelines of evacuation behaviors in disasterprevention training and drill based on actually taken actions. It is difficult changing human behavior,
but the rewards are worth the effort.
ACKNOWLEDGMENTS
The authors thank for Weathernews/Mr. Honda Shinichi for vast and necessary data and SEC/Mr. Doi
Norio, Dr. Ishino Fukuya, Waseda University/Professor. Yoshie Osamu for text mining techniques inJapanese. Professor Charles Scawthorn, Mr. Koji Simo, Ms. Dogo Hitomi for proceeding this study.
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M.Hamada and N.Y. Yun. (2011). “Future Directions of Earthquake-Tsunami Disaster Reduction
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Miles,M.B. and Huberman, A.M. (1994) “Qualitative Data Analysis, 2nd ed.”, Sage, Thousand Oakes.
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Inoue, M., Matsufuji, Y., Yanase, R. (2007). “Waste management and countermeasures of earthquake
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