近年の台風による住宅への強風被害の現状とリスク低減のための提案 --台風2018年21号と2019年15号の調査結果を踏まえて--

Abstract

The present report summarizes wind-induced disasters caused by recent two typhoons Jebi (2018) and Faxai (2019). First, the historical changes in numbers of fatality and missing as well as number of damaged houses and economic losses over the last 80 years are illustrated together with those brought by the two typhoons. Thereby, it is emphasized that the society in Japan is still vulnerable when it comes to wind disasters especially in urban areas. Second, the essential outcomes from the surveys conducted by the authors' group are reported; i.e., damage rate is significantly high for old houses and houses with clay tile roof, whilst the rate is low for new houses (especially, constructed after 2000). This leads to the suggestion that wind retrofit of those old houses is necessary and effective to reduce wind induced disaster risk in the future, whereas upgrading of requirements in the building standard code has less impact. Third, important findings after the questionnaire survey on the mind of house owners regarding repair work of damaged house are introduced; e.g. less willingness to upgrade wind-resistant performance even after damage to houses. On these basis, it is proposed that the incentive to upgrade windresistant performance should be developed through subsidies and/or insurance scheme in order to mitigate future wind disasters, in combination with activities for increasing public awareness toward wind disaster.