Relocation After Tsunamis in the Sanriku Area and the Condition of Fishing Villages Two Years After the 2011 Great East Japan Tsunami - Post-Tsunami Hazard: Reconstruction and Restoration - page 55

the other hand, in Karakuwa most fi shermen told us that they insist to evacuate
offshore with their boat in case of future tsunamis. The situation we learned from
fi shermen in Karakuwa is quite unique in comparison to other villages in Miyagi
prefecture too.

4.4.3 Difference in Altitude and Distance

of the Relocation Areas

From the examples introduced in the previous section, it is clear that all three
villages had experienced large tsunamis due to their location along the Sanriku
area. They also had experience in individual or group relocation that proved to be
insuffi cient for the 2011 tsunami. Reports from past events also showed that the
residents moved back to low land for various reasons and the villages suffered
again following the 2011 tsunami. The 2011 tsunami was the event that led the vil-
lagers to agree to move the entire residential area to high ground for the fi rst time.
Figure 4.9 shows the average differences in distance and altitude of relocating to
high ground after the 1933 Showa-Sanriku tsunami as reported by Yamaguchi
( 1972 ). This distribution is consistent with the study by Tanakadate and Yamaguchi
( 1938 ) in that most of the data are clustered around a distance shorter than 400 m
and altitude lower than 15 m. Data from the three villages affected by the 2011
tsunami interviewed in this study were added to the same fi gure. It is clear that all
villages have planned to move to areas where the altitude difference is higher than
30 m and the distance is longer than 400 m; such relocation to ensure that all vil-
lages will be safe from future tsunamis because their destination point will be
40-50 m higher than sea level.

60

Niranohama

45

Tadakoshi

Yagawa

30

15

Tsunami in 1933
Tsunami in 2011

0

0 400 1200 1600

800

Difference in distance (m)

Fig. 4.9 Comparison of the difference in distance and difference in altitude between moving to
high ground after the 1933 Showa-Sanriku and after the 2011 Great East Japan tsunami