The deceleration processes of debris flows and their depositions due to the change of channel width, at the flume which has constant bed slope, are experimentally studied.
Change of the front velocity of debris flow is explained as a hypothetic model in conjunction with decrement of the concentration in the front of debris flow. The deceleration along the channel are different according to the incremental ratio of channel width represented by T. As the T increases, the possibility to abate the impactive force and the velocity is improved to some extent.
Also, characteristics of residual deposits in relation to T or Cd are discussed.
