Abstract
A field experiment was planned and carried out in the catchment area of Shichigashuku Reservoir in order to study the transport of fine suspended materials (wash load) contained in flood water. In data processing, focus is made on the difference of behavior between relatively coarse component and finer one: A careful check is made on the conservation of each component by time integration of its flux across the measuring stations so that sorting process at the upstream end of the reservoir is clarified. The most interesting output of this study is that a percentage of relatively coarse component has a peak with a time lag of few hours after the peak of flood discharge.
