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.