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您的检索式：作者名="Dabney, S. M."
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| 1 | CONTROL OF GULLY EROSION USING STIFF GRASSES显示文摘Concentrated flow can cause gully formation on sloping lands and in riparian zones. Current practice for riparian gully erosion control involves blocking the gully with a structure comprised of an earthen embankment and a metal or plastic pipe. Measures involving native vegetation would be more attractive for habitat recovery and economic reasons. To test the hypothesis that switchgrass (Panicum virgatum L.) hedges planted at 0.5-m vertical intervals within a gully would control erosion, a series of hedges was established in four concentrated flow channels. Two of the channels were previously eroded trapezoidal channels cut into compacted fill in an outdoor laboratory. The other two channels were natural gullies located at the edge of floodplain fields adjacent to an incised stream. While vegetation was dormant, artificial runoff events were created in the two laboratory gullies and one of the natural gullies using synthetic trapezoidal-shaped hydrographs with peak discharge rates of approximately 0.03, 0.07, and 0.16 m3/s. During these tests flow depth, velocity, turbidity, and soil pore water pressures were monitored. The fourth gully was subjected to a series of natural runoff events over a five-month period with peaks up to 0.09 m3/s. Flow depths in all tests were generally < 0.3 m, and flow velocities varied spatially and exceeded 2.0 m/s at the steepest points of the gullies. Erosion rates were negligible for controlled flow experiments, but natural flows in the fourth gully resulted in 1 m of thalweg degradation, destroying the central portions of the grass hedges, most likely due to the highly erodible nature of the soils at this site. Geotechnical modeling of soil steps reinforced with switchgrass roots showed factors of safety > 1 for step heights < 0.5 m, but instability was indicated for step heights >1 m, consistent with the experimental observations. | F. D. SHIELDS Jr. S. M. DABNEY E. J. LANGENDOEN D. M. TEMPLE | 2005 | International Journal of Sediment Research2005，20，4： | 0 |
| 2 | MANAGEMENT AND SUBSURFACE EFFECTS ON RUNOFFAND SEDIMENT YIELD FROM SMALL WATERSHEDS显示文摘Research on erosion plots and small watersheds with upland loessal soils containing hydraulically-controlling subsurface horizons showed that as scale increases so does the amount ofarmual runoff Theamount of runoff from 2 to 3 ha watersheds was twice that from 0.008 ha plots. However, the ratio ofrunoff from watersheds to plots was 3.0 from Dec through March, and only 1 .7 during the rest of the year.Georeferenced penetrometer resistance measurements documented the presence of restrictive layers within1 m of the soil surface. Observation wells showed the presence of spatially varying perched water tables.We propose that the runoff difference between plot and watershed scales was re1ated to the increasingimportance of hydraulically restrictive subsurface horizons, especially during the winter months. Waterinfiltrated into linear backslope areas that the plots represent may converge in concave toe slopes areas,creating wetter antecedent conditions and return flow contributions to surface runoff No-tillmanagement reduced sediment production by about 90% on plots and by at least 95% on watersheds; notill reduced runoff about 10% from both plots and watersheds in this study. Conservation managementaffected hydraulic resistance at the soil surface rather than the permeability of deep restrictive layers. | Dabney, S. M. L. D. Meyer C. E. Murphree( USDA-ARS, National Sedimentation Laboratory, Oxford, MS, USA)R. L. Raper(USDA-ARS, National Soil Dynamics Laboratory, Aubum, AL, USA) | 2000 | International Journal of Sediment Research2000，15，2： | 0 |
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