Disasters caused by many debris flows and slope failures under the effect of the active baiu-front occurred in the western part of Hiroshima Prefecture on June 29, 1999. The rainfall was characterized by the distribution of very locally heavy intensity of 50 mm/hr. The concentrated damaged areas, where we could easily find out some inherent factors such as geological, geographical and vegetational properties, fitted in such zones of high hourly rainfall. We think that the rainfall patterns as the inducing factors were very important and decisive. Although the scales of most debris movements and slope failures were not very large, many victims and lots of damages were found in the residential areas. So the disaster prevention system must be more intensively promoted with the consideration of ideal land utilization.
