Principal Investigator: Shih-Chao Chiang (Georgia Institute of Technology)
Principal Investigator: David E. Radcliffe (University of Georgia)
Principal Investigator: Shih-Chao Chiang (Georgia Institute of Technology)
Principal Investigator: William P. Miller (Georgia Institute of Technology)
Sponsor: GWRI
Start Date: 1987-03-01; Completion Date: 1987-03-01;
Keywords: flocculation, soil erosion, infiltration, permeability
Description:
Lateral movement of infiltrating water frequently occurs at the surface of Southern Piedmont soils and may occur below the surface when dense layers are present at a shallow depth. Our objective was to determine to what extent lateral movement occurred and what mechanisms might be responsible for the low permeability. Because of equipment problems with a field rainfall simulator we were unable to address subsurface lateral flow, but a greenhouse and laboratory experiment provided information on surface lateral flow. In Experiment I., infiltration rates declined steadily in three soils, two of which had final infiltration rates so low that run-off would occur under all but very low intensity rainfalls. The decline in infiltration was attributed to dispersion of soil particles upon impact by raindrops and the formation of a low permeability washed-in layer of dispersed clay particles just below the surface. In Experiment II, it was shown that soil dispersion varied among soils and could be severe when infiltrating water was low in mineral content (eg. rainfall) and soil pH had been raised through liming.