Abstract
Typhoon No. 14 moved along the west coast of Kyushu from 4th to 7th September 2005 and caused severe damages at many locations mainly in Miyazaki-prefecture, Kagoshima prefecture and Oita prefecture. This typhoon moved at a very slow speed of travel varying from 25 km/h to 30 km/h in Kyushu area and this caused successive formation of strong clouds for a long time in the east side of the Kyushu Mountain Region which exists on the right side to the direction of this typhoon. According to AMeDAS data, the rainfall at Osumi in Kagoshima prefecture exceeded 900 mm and at Mikado in Miyazaki prefecture exceeded 1300 mm since the beginning of the rainfall. This typhoon is characterized by heavy rains and many places in the south and east of Kyushu have exceeded the maximum record of rainfall. Flood disaster hit many places along the Oyodo River and Gokase River including their tributaries and more than 6000 houses suffered from inundation above floor. Geodisasters also occurred at many places due to this typhoon and 22 lives were lost and some villages had been isolated for a long time. In this paper, the mechanisms of slope failure observed in the geodisasters in Kyushu area caused by Typhoon No. 14 in September 2005 are mainly outlined in relation to the rainfall characteristics and geological and soil mechanical aspects.
