On the Time Variation of RiLL Patterns and Sediment Out of Bare Slope

Small channels generated on bare slope by rainfall grow with time. Sediment run-off from the slope also increases with change in the plane patterns of the channels. In order to estimate the sediment run-off from bare slopes. It is important to know the relationship between the characteristics of run-off and the geometric properties of channel patterns. In this study, experiments were carried out using Masa soil while supplying artificial rainfall on the slope. The time variations of semident run-off were measured. As well, time variations of plane patterns of channels were photographed, and the degree of complication of the patterns was described as fractal dimensions. As a results of both experiments and analysis, it is clear that the total plane area of channels was eventually close to constant. But the sediment run-off from slope gradually increased with time. The fractal dimention of channel patterns increased and decreased with time in the case of a gentle slope angle, but did not change with time in the case of steep angle.