Submitted to: Proceedings Mitteilungen Der Deutschen Bodenkundlichen Gesellschaft
Publication Type: Proceedings
Publication Acceptance Date: July 30, 1999
Publication Date: September 30, 1999
Interpretive Summary: Sediment movement from upland areas is determined by many factors, including soil and soil surface conditions, rainfall regime, surface topography, soil and cropping management, and mechanical control practices. Rills and ephemeral gullies are the major sources of sediment on sloping land of field-size areas. Their development depends on slope topography, soil type, surface roughness, and many other factors. This report summarizes the experimental results of a simulated rainfall study conducted at the National Sedimentation Laboratory of rill development and soil loss in relation to soil properties, slope steepness, and surface roughness. It was written for a German-speaking audience and was intended to familiarize this audience (The German Soil Science Society) with ongoing research. This information has been presented in more detailed form elsewhere in English journals.
The development of rill pattern was studied for different soils, surface roughness, and slope steepness and related to the measured soil losses. The results indicate that changes in the developing rill pattern is greatest during the early stages of the rainfall-runoff process, but that the development tends to an equilibrium condition. This equilibrium is independent of the initial conditions and varies within a narrow range depending on factors such as slope, soil properties, and surface roughness. Soil loss is highest when runoff shows the greatest changes. Otherwise, deviations from the runoff equilibrium determine the magnitude of soil loss.