Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/3/1996
Publication Date: N/A
Technical Abstract: Different hydrologic conditions, especially seepage and drainage gradients near the surface, have a profound effect on the dominant erosion processes. A laboratory study was designed to quantify sediment delivery under different levels of exfiltration (seepage) and infiltration (drainage) gradients. Results showed that severe rilling occurred under seepage conditions and sediment delivery rates were 5 to 10 times greater than those obtained under drainage conditions. Even under drainage conditions, there was a significant reduction in sediment delivery from a free-drainage situation when an assisted-drainage condition was created with the water table maintained at 10 cm below the soil surface. Changes in the near-surface hydraulic gradients changed both soil erodibility and the dominating erosion processes although the soil was unchanged.