Serious Erosion of the Southern Sendai Coast Due to the 2011 Tohoku Earthquake Tsunami and Its Recovery Process - Post-Tsunami Hazard: Reconstruction and Restoration - page 225

Table 15.1 Number of fl ora and fauna species before and after the 2011 Tsunami

After 2011
Tsunami Place Survey items Before 2011 Tsunami

Abukumagawa
River mouth

Fishes 34 (1) in 2004 30 (0) in 2012

36 (2) in 2009

Benthos 40 (2) in 2004 33 (0) in 2012

48 (2) in 2010

Plants 144 (6) in 2001 228 (8) in 2012

213 (7) in 2007

Birds 48 (4) in 2000 37 (4) in 2012

39 (1) in 2005

Amphibians, reptiles, and
mammals

6 (0) in 1998 10 (0) in 2012

8 (1) in 2003

Land insects 224 (26) in 2002 230 (21) in 2012

331 (31) in 2008

Plants 67 (4) in 2002 No data (4) in 2011
248 (11) in 2012
Birds 37 (4) in 2002 55 (7) in 2011
45 (5) in 2012
Land insects 147 (23) in 2002 229 (25) in 2012
Numbers in parentheses indicate the number of important species (Source: Tohoku Regional
Bureau, Ministry of land, Infrastructure, Transport and Tourism of Japan. http://www.thr.mlit.
go.jp/sendai/kasen_kaigan/fukkou/image/04data.pdf)

Beaches from
Sendai Port to
Isohama Port

Abukumagawa River mouth, the number of fi sh, benthos, and land insect species
decreased after the tsunami from 34 in 2004 and 36 in 2009 to 30 in 2012, from
40 in 2004 and 48 in 2010 to 33 in 2012, from 224 in 2002 and 331 in 2008 to 230 in
2012, respectively; but those of other species did not show clear changes after the
tsunami.
The 2011 tsunami caused great damages in the study area but simultaneously left
many datasets such as tsunami runup and inundation heights (Mori et al. 2012 ),
damages of coastal structures (Anawat et al. 2012 ), coastal morphology change
(Tanaka et al. 2012 ; Udo et al. 2012 ), and ecosystem change. The monitoring sur-
veys of coastal morphology and ecosystems will continue for at least several years.
It is required to continue the surveys on the coastal morphology and ecosystems for
decades and evaluate the effects of the tsunami and reconstructions of coastal struc-
tures on them.

15.5 Conclusions

This study elucidated the characteristics of coastal morphology changes caused by
sediment transport on the southern coast of Sendai Bay by analyzing the topograph-
ical measurement data before and after the 2011 tsunami and aerial video taken