Abstract
A mathematical model was developed to simulate soil erosion and sediment transport along rills in a field. For the model, a continuity equation for sediment with a term for the sediment transport capacity of rill flow was used. The Yang sediment transport equation was used to estimate this capacity. First, the equation of the model was solved under various intensities of rainfall events occurring during the observation, and the characteristics of the sediment load distribution along the rill in the field for study were clarified based on the results obtained. Second, net rill erosion at many positions along the rill was calculated using the solutions of the equations. Due to the good agreement between the calculated and observed values, the sediment transport model was found to be valid. Third, the effect of the sediment transport rate on the detachment rate along the rill was analyzed. The results showed that the effect was not appreciable in the case of moderate or higher rainfall intensity throughout the rill, while it became more pronounced when the distance along the rill increased under low intensity rainfall.
