Effect of Rainfall Intensity on Channel Sediment

Soil erosion is one of the most influential problems of land degradation worldwide. Soil erosion has many forms, such as splash erosion, inter-rill erosion, rill erosion and gully erosion. Rills caused by runoff over erodible soil are usually irregular in profile and cross section and may not approximate any regular geometrical shape. Therefore, the flow hydraulics in rills may differ greatly from the hydraulics of large channel flow. In this study, the experimental rainfall simulations were conducted to investigate the change of channel sediment discharge by rainfall intensity due to the formation of inter-rills, rills, gullies, and streams. Four rainfall events conducted with two rainfall intensities (2.33 and 2.67 mm.min
^-1
), each rainfall intensity is applied with two model cases (first is natural soil, and the second contains 50% natural soil+ 50% sand), with land slope 10
^o
, rainfall duration was 90 min, and the flow velocity of the channel is 0.1 m.s
^-1
. The results show that the cumulative sediment amount increases with the an increase of rainfall intensity, the channel sediment increase with the initiation of rills.