Impacts of Recent Climate Change on Flood Disaster and Preventive Measures

This paper examines flood disasters caused by climate change focusing on two floods occurring on Japan's southwest island of Kyushu during record precipitation exceeding 1,000 mm. Our examination results emphasize the urgent necessity of implementing dam measures to prevent serious dam accidents at all costs and adequate action against driftwood and other waste materials to prevent them from interfering in dam operation. Changes in natural weather and other patterns, e.g., heavy rainfalls 1,900 mm recorded in the Miyazaki Prefecture during Typhoon 14 in 2005 and 1,200 mm in the Kagoshima Prefecture Sendai River basin in five days of torrential rain in 2006, have made it clear that conventional measures for coping with such occurrences are no longer adequate. Just 300 mm of precipitation during Typhoon 10 in 2003, for example, triggered catastrophic results in Hokkaido, where heavy rainfall rarely occurs and there is non immunity against 300 mm rainfall. Since global warming and its attendant influences are expected to continue and to bring condition of non immunity against an increased potential of disaster to whole country, the need for better knowledge and ideas on disaster prevention are urgently required.