An analysis of the circumstances of death in the 2011 Great East Japan Earthquake (15th WCEE)

Unit for Liveable Cities, Graduate School of Engineering/Medicine, KYOTO UNIVERSITY

京都大学大学院　工学研究科・医学研究科　安寧の都市ユニット

AN ANALYSIS OF THE CIRCUMSTANCES OF DEATH

IN THE 2011 GREAT EAST JAPAN EARTHQUAKE

M. Koyama, A. Yoshimura & J. Kiyono

Graduate School of Engineering Kyoto University, Japan

N. Ishii

Building Research Institute, Japan

S. Mitani & S. Koh

Graduate School of Medicine Kyoto University, Japan

15th WCEE in Lisbon, 24-28 September 2012 1



Damage summary of The Great East Japan Earthquake of March 11, 2011 Death1) : 16,278 Missing1) : 2,994 Totally collapse1) : 129,198 Washed away houses2) : ~78,000

Purpose of this study We review the circumstances of victims at the time

of death in the damaged area and present a detailed analysis of mortality in the tsunami inundation areas.

Introduction

1) FDMA : Situation Report No.1452) MLIT : Summary of the Field Survey on The 2011 off the Pacific coast of Tohoku Earthquake, No.1.

Tsunami height map by JMA

2



Data sources

FDMA : Situation reports Municipality level damage numbers that are

casualty, building damage, fire, etc…

Prefectural Polices : Casualty information The body-identification information of the

Iwate, Miyagi and Fukushima prefectural police

Geographical inundation digital map Inundation area and washed away area

map

500m grid population data of the census

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0.00%

0.20%

0.40%

0.60%

0.80%

1.00%

1.20%

1.40%

fata

lity

rate

Age

male

female

Fatality rate by age and gender

The death rates of those in the over 60 age classes are sharply higher. Furthermore, as age increase, the death rate of males increases.

4



Spatial distribution of death

Deaths are concentrated in costal inundation areas of the tsunami.

The most of the deaths occurred in the washed-away areas.

Death

Washed-away Area

Inundation Area

5



Fatality rate of inundation situation

The death rates in the age classes of those over 60 were exceptionally high.

0.00%2.00%4.00%6.00%8.00%

10.00%12.00%14.00%16.00%18.00%20.00%

0-4

old

5-9

old

10-1

4 ol

d

15- 1

9 ol

d

20-2

4 ol

d

25-2

9 ol

d

30-3

4 ol

d

35-3

9 ol

d

40-4

4 ol

d

45-4

9 ol

d

50-5

4 ol

d

55-5

9 ol

d

60-6

4 ol

d

65-6

9 ol

d

70-7

4 ol

d

75-7

9 ol

d

80-8

4 ol

d

85 a

nd o

ver

fata

lity

rate

Age groups

Totally inundation area

Washed away area

Inundation Area withoutwashed away area

6



Death toll by inundation situation

Many deaths occurred at altitudes less than 11 meters, and especially of less than 6 meters

0

50

100

150

200

250

300

350

400

Dea

th to

ll

Elevation (m)

Totally inundation area

Washed away area

Inunadation area withoutwashed away area

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Conclusion

We clarified the relationship between inundation/washed-away areas and the situations in which death occurred.

In particular, from the age-classified death rates, we addressed the issue of elderly mortality.

If more important information becomes, a more concrete analysis can be made. Spatial inundation depths, the location of

people at the time of the tsunami’s arrival, and the construction dates, structures, and number of floors of buildings.

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An analysis of the circumstances of death in the 2011 Great East Japan Earthquake (15th WCEE)

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