Skip to main content
ARS Home » Midwest Area » West Lafayette, Indiana » National Soil Erosion Research Laboratory » Research » Publications at this Location » Publication #90111
Title: NEAR-SURFACE HYDRAULIC GRADIENT AND EROSION PROCESSES

Author
item WELLS, L - PURDUE UNIVERSITY
item HUANG, CHI-HUA - PURDUE UNIVERSITY
item Norton, Lloyd
item GABBARD, D - PURDUE UNIVERSITY

Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: 5/26/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Different near-surface hydraulic gradients, especially due to seepage and drainage, representing conditions that occur at different locations on the hillslope may have a profound effect on the dominant erosion processes. A laboratory plot-box system was designed to recreate hillslope hydrologic processes and quantify effects of near-surface hydraulic gradients on erosion. The plot-box system consists of two soil boxes: a 1.8-m long sediment feeder box and a 5-m long test box, which can be set to either seepage or drainage conditions. Different combinations of rainfall, slope and hydraulic gradients were used to simulate hydrologic conditions of a 5-m segment of a hillslope. Results showed that under seepage conditions, rilling occurred, and runoff from the feeder box caused additional sediment transport, indicating a transport limited sediment regime. Under drainage conditions, erosion was limited to surface scour and the added feeder sediment was deposited in the test box despite sediment concentrations at 20 to 50 percent of those under seepage condition. These results demonstrated that changes in the near-surface hydraulic gradient affected not only the dominant erosion processes, but also the sediment transport and deposition regimes. Spatial and temporal variability in hillslope erosion processes can be attributed to changes in the near-surface hydraulic gradient on the landscape.