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ARS Home » Midwest Area » West Lafayette, Indiana » National Soil Erosion Research Laboratory » Research » Publications at this Location » Publication #133356
Title: SEDIMENT TRANSPORT FROM INTERRILL AREAS UNDER WIND-DRIVEN RAIN

Author
item ERPUL, GUNAY - ANKARA UNIVERSITY
item Norton, Lloyd
item GABRIELS, D - GHENT UNIVERSITY

Submitted to: Journal of Hydrology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/29/2002
Publication Date: 1/24/2003
Citation: Erpul, G., Norton, L.D., Gabriels, D. Sediment transport from interrill areas under wind-driven rain. Journal of Hydrology. 2003. 276(2003) 184-197.

Interpretive Summary: Soil erosion by water is a serious problem in many parts of the world. It leads to soils degradation and threatens the worlds potential to produce food and fiber. Many factors can either cause an area to erode under rainfall or not. In most rainstorms that produce severe runoff and erosion, high winds are associated with the storm. Little knowledge exists about the effect wind has on soil erosion by water because before researchers did not have the tools to study it. We conducted a study to measure how wind affected soil erosion in shallow flowing water in a unique wind/rainfall simulator facility. We found that wind depending on the direction and speed can have a large impact on the amount of erosion and the time to runoff with the same amount of rain. If a hillslope faces the direction of the wind more erosion occurs because runoff occurs faster and more soil is detached by the raindrops. On slopes facing away from the wind less erosion occurs because it takes longer for runoff to occur and less soil is detached by the raindrops because of the angle of impact. The practical impact of this research is that improved soil conservation techniques can be developed using strategic placement of windbreaks on the landscape relative to the prevailing wind. Also more accurate predictive tools can be developed that include wind as a factor to better target areas on the land for conservation.

Technical Abstract: Wind and water erosion processes have traditionally been separately studied, and independent models were developed to predict soil erosion under either wind or rain. In nature, erosive rainstorms are usually associated with high winds. Therefore, a quantification of wind and rain interactions and the effects of wind on detachment and transport processes provides a great opportunity for a given prediction technology to improve the estimation of erosion. This paper presents experimental data obtained on Interrill erosion processes under wind driven rain. Ina wind tunnel facility equipped with a rainfall simulator, windless rains and the rains driven by horizontal wind velocities of 6, 10, and 14 ms-1 were applied to three agricultural soils packed into 20 by 55 cm soil pan at both windward and leeward slopes of 7, 15, and 20%. Wind-driven rainsplash transport was measured by trapping the splashed particles at distances on a 7-m uniform slope segment in the upslope and downslope directions, respectively, for windward and leeward slopes. The process was adequately described by relating the rainsplash transport rate to the rainfall parameter, fluxes of rain energy or momentum, and wind shear velocity by log-linear regression technique. Sediment transport by rain-impacted thin flow was measured by collecting sediment and runoff samples at 5-min intervals after runoff onset. This process was also adequately described by rainfall and flow parameters. Comparing the process contribution to the total sediment transport, it is concluded that rainsplash transport is a significant process that should not be neglected in accurately predicting Interrill water erosion under wind-driven rain.