Modeling the impacts of no-till practice on soil erosion and sediment yield with RUSLE, SEDD, and ArcView GIS

The revised universal soil loss equation (RUSLE), the sediment delivery distributed (SEDD) model, and ArcView GIS were used to estimate the impacts of no-till practice on soil erosion and sediment yield in Pataha Creek Watershed, a typical dryland agricultural watershed in southeastern Washington. The results showed that the average cell soil loss decreased from 11.09 to 3.10 t/ha yr for the whole watershed and from 17.67 to 3.89 t/ha yr for the croplands under the no-till scenario. Likewise, the average cell sediment yield decreased from 4.71 to 1.49 t/ha yr for the entire watershed and from 7.11 to 1.55 t/ha yr for the croplands under no-till practices. The major reason why no-till practice can significantly reduce the soil erosion and sediment yield is that it prevents rill generation which through rill erosion ultimately contributes up to 90% of the soil erosion in the Inland Pacific Northwest region. (C) 2004 Elsevier B.V. All rights reserved.