A preliminary impact assessment of typhoon wind risk of residential buildings in Japan under future climate change

This paper performs a quantitative impact assessment of
the climate change on typhoon wind risk, focusing on
residential buildings in Japan. The risk is assessed based on
(1) the typhoon event set extracted from the simulation by
the super-high resolution atmospheric general circulation
model developed within the KAKUSHIN program; (2) the
probabilistic typhoon modeling scheme developed by our
group; (3) a fragility model empirically estimated on the
basis of the damage report of typhoon Songda in 2004 and
the reproduced wind field by a mesoscale meteorological
model; JMA-NHM. The main results are that in the future
(2075–2099) at most locations of Japan: (1) extreme wind
events (10-minute sustained wind speed exceeding 30 m/s)
are more likely to occur; (2) the median of the annual
maximum wind speed decreases; (3) the expected number
of damaged residential buildings decreases, assuming that
the profile of the building portfolio remains unchanged.
Based on these results, the assumptions and inputs to the
assessment are critically reviewed. Thereby, the needs of
further research efforts toward more credible and
comprehensive assessment are addressed.