ABSTRACT
To develop and/or improve process-and event-based erosion models fundamental pathways and processes influencing interrili erosion must be defined and understood. Plot-based erosion experiments conducted under controlled laboratory setting provide the best scenario for isolating and investigating these pathways and processes. We investigated 1) which interrili erodibility (Ki) calculation best represents the overall Ki for a given soil, 2) how Ki values for different soil surface conditions (seedbed, sealed, crusted) vary with time, and 3) how seal/crust formation influences changes in detachment and transport processes during a simulated rainfall event. Five U.S. soils and four Austrian soils, ranging in texture from sandy loam to clay, were exposed to sequences of simulated rainfall of varying intensities and durations. Soil loss and runoff were measured at 5 min intervals from three soil surfaces: seedbed, wet sealed, and dry crusted conditions Ki values were calculated from two equations (E = Kii P Sf and E = Kiq I q Sf) using measured soil loss (E), rainfall intensity (I), flow discharge (q), and a slope factor (Sf). The interrili erosion equation, E = Kiq I q Sf, provided the best description of sediment delivery from interrili areas. Ki values for initially air-dry, wet sealed, and dry crusted soil surface conditions did not differ significantly, however, Kİ values calculated for selected times during each rainstorm varied between soils. Energy associated with simulated rainfall broke down weakly aggregated soils and contributed to the formation of well-developed, high strength surface seals and crusts, resulting in detachment-limiting soil surface conditions.
