抄録
Movable bed experiments using a wide laboratory flume without influence of fixed side walls were carried out in this study in order to observe the long-term deformation process of channel plane forms. The channel plane form deforms with bank erosion, braided streams and bed geometry in the channel. In this experiment, the initial straight channel changed to the plane shape with narrow parts (nodes) and wide parts (anti-nodes) finally. The plane shape with narrow parts and wide parts was seen several times during the deformation process. The formations of the former watercourses were also seen in the process that the channel plane shape shifts to a renewed plane shape with different phase.