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 47

4.1 Introduction

Sanriku is well known as one of the areas in Japan most frequently hit by tsunamis,
having experienced two great local tsunamis in 1896 (Meiji-Sanriku) and 1933
(Showa-Sanriku) as well as the far-fi eld tsunami from Chile in 1960. Figure 4.1
shows recorded historical tsunami heights (two events in 1896 and 1933) in the
south of the Sanriku area of approximately 10 m or less (Suppasri et al. 2013 ). In
contrast, the 2011 Great East Japan tsunami reached as high as 20 m and was higher
than 10 m in most areas. Furthermore, the tsunami inundation area caused by the
2011 tsunami was particularly large compared to the impact from the tsunamis in
1896 and 1933. As a result, many areas were greatly damaged by the 2011 tsunami
(Suppasri et al. 2013 ). Based on a study of the Government of Japan's Cabinet offi ce
( 2011a ), relocation was one countermeasure implemented after the 1896 tsunami,
with seven of the 43 villages reported as having implemented group relocation.
After the 1933 event, all 38 villages in Iwate prefecture relocated as a group,
whereas 11 of 60 villages were reported to have relocated in Miyagi prefecture. In
addition, land elevation was increased in one village after the 1960 Chile tsunami.
The objective of this chapter is to examine relocation efforts in the Sanriku area
following the 2011 tsunami, including a comparison with the area's past experience.
We focused on interviewing fi shermen as aquaculture is the main productivity in
these small villages. In addition, fi shermen are more vulnerable to tsunami because
they work at the sea and many of them are likely to drive their boats off shore to save
their boats against tsunami. Based on contact availability and participation, inter-
views of 20 fi shermen were conducted during June and July of 2013 in three target
villages: Tadakoshi (Kesennuma city), Nirahohama (Minami-Sanriku town) and
Yagawa (Ishinomaki city), as shown in Fig. 4.1 .

Fig. 4.1 Study areas in the southern Sanriku area and maximum tsunami runup heights