This study was designed to evaluate the nature and magnitude of spatial variations in soil physical and hydrologic properties in relation to the "partial contribution (source) area" concept of generation of overland flow and soil loss from a Typic Hapludalf at Columbus and an Aquultic Hapludalf at Coshocton, Ohio. In addition, the impact of landscape position on soil erodibility on hillslopes of Mt. Elgon, Uganda, and Columbus, Ohio, were also investigated.;In order to characterize the source areas, research plots at the Columbus site and a watershed at the Coshocton site were cropped to corn under similar management. Areas (subplots) presumed to respond differently hydrologically were identified and ranked into categories on the basis of corn height measured 8 weeks after planting. Soil measurements were taken across, and down the predominant slope and from within the subplots. Rainfall simulations and infiltration tests were conducted within the demarcated subplots at the Columbus site.;The spatial structure and magnitude of variability in soil properties were analyzed using variograms. Significant spatial variability in soil properties were found at a microscale (e.g. at the Columbus site, saturated hydraulic conductivity, K;Based on these findings, it is envisaged that in the 21st century, management efforts and resources to conserve soil and water will be more efficiently tailored to the vulnerable source areas rather than entire watersheds.;Results from the studies of the impact of landscape position on erodibility, highlighted the complexity of the nature of hydrologic processes on hillslopes.
展开▼
