Effectiveness of Real-Time Near-Field Tsunami Inundation Forecasts for Tsunami Evacuation in Kushiro City, Hokkaido, Japan - Post-Tsunami Hazard: Reconstruction and Restoration - page 168

Fig. 11.14 Tsunami inundation area ( blue area ) forecasted by the NearTIF algorithm. Locations
of the participants of the tsunami evacuation drill in Kushiro City; the high and elementary school
buildings designated as tsunami evacuation buildings by the Kushiro City Offi ce (Source: NHK
Television Network 2013 )
building was an elementary school building located farther inland, approximately
3.7 km from the shoreline, and 3.5 m above the mean sea level (Fig. 11.14 ).
In the tsunami evacuation drill, we assumed that the JMA works as it should and
delivers the tsunami messages to the residents of Kushiro within 3 min after the
earthquake. Upon receiving the announcement of the tsunami warning, the partici-
pants immediately evacuated to the nearest evacuation building. At this point in
time, they did not know the tsunami fl ow depth at their exact position or the limit of
the tsunami inundation. That information was not given because we preferred to
wait until we had more data so we could obtain more reliable earthquake source
parameters, and we needed more time to obtain the tsunami inundation forecast map
from the NearTIF algorithm. At 10 min after the initial warning, both groups receive
new information for the tsunami inundation forecast map. They viewed the map via
Google Maps over the Internet on a tablet computer (Fig. 11.15 ). The two groups
made different decisions based on their own situations.
The fi rst group was just in front of the high school building when they received
the newly available tsunami inundation forecast. According to the tsunami inunda-
tion forecast, the building they were about to use as an evacuation building could be
inundated by the incoming tsunami, and the tsunami at that building could be 3 to
4 m high. They considered the position of the evacuation building that is 2.8 m
above mean sea level, the height of the building, and the tsunami inundation fore-
cast (Fig. 11.14 ). They also considered evacuating to another evacuation building
that would not be inundated by the tsunami, according to the tsunami inundation
forecast. However, their fi nal decision was to go to the initial evacuation building