|Wang, Bin - Beijing Forestry University|
|Zhang, Fenli - Northwest Agricultural & Forestry University|
Submitted to: Earth Surface Processes and Landforms
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/12/2017
Publication Date: 4/12/2017
Citation: Wang, B., Steiner, J.L., Zhang, F., Gowda, P. 2017. Impact of rainfall pattern on interrill erosion process. Earth Surface Processes and Landforms. doi:10.1002/esp.4140.
Technical Abstract: The impact of rainfall pattern on the interrill erosion process is not fully understood despite its importance. Systematic rainfall simulation experiments involving different rain intensities, stages, intensity sequences, and surface cover conditions were conducted to investigate the impacts of rainfall patterns on interrill runoff and erosion processes. Five rainfall patterns designed with the same total kinetic energy and precipitation amount (i.e. increasing pattern, decreasing pattern, rising-falling pattern, falling-rising pattern and constant pattern) were randomly delivered on a pre-wet clay loam soil surface at 10° slope gradient. Significant differences in soil losses were observed among different rainfall patterns and stages, but no obvious difference was observed in runoff. Kinetic energy (KE) could enhance sediment transport capacity of raindrop-impacted flow, and soil losses were nine times higher with constant rainfall pattern (CST) than that with no KE. Varied-intensity patterns promoted erosion regime transforming from detachment-limited condition to transport-limited condition in the interrill area. The critical values of flow shear stress (t), stream power (') and unit stream power (uS) were 0.29 Pa, 0.002 N/m·s and 0.001 N/s. In particular, these hydraulic variables might be enhanced in high-intensity events. This study not only expanded the understanding of the mechanism of interrill sediment transport capacity and detachability, but also provided a useful database for developing event-based interrill erosion prediction models.