Slope failure resulting in debris-flow disaster of Atsumari River Basin
@A debris-flow disaster occurred in the Atsumari River Basin, Minamata City, Kumamoto Prefecture, in the early dawn on July 20, 2003. A slope failure of unstable and jointed andesite lava near a knick point in the midstream segment of the Atsumari River Basin immediately resulted in the debris flow. The slip occurred around the boundary between the andesite lava and the underlying weathered tuff breccia acting as a permeable layer and an aquiclude, respectively.