Abstract
Temporal responses of sand waves, mean flow depth and reach averaged sediment transportation rate due to periodic change of flow discharge were investigated on the basis of flume tests using the graded and the uniform sediment. They were also predicted by taking the reference grain size for sand wave transformation into account. The predicted results were verified with the experimental results. From the results of experiments and predictions, it was found that the width of loop in the graphs of dischargewave height and discharge-flow depth for the graded sediment were smaller than that for the uniform one under same flow discharge condition. Therefore, time lag of response for the graded sediment is smaller than that for the uniform one. And, the peaks of wave length, wave height and flow depth indicated the positive time-lag to the peak of flow discharge, while the peak of sediment transportation rate indicated the negative time-lag to it.
