Including runoff in USLE-type empirical models is expected to improve plot soil loss prediction at the eventtemporal scale and literature yields encouraging signs of the possibility to simply estimate runoff at thesespatial and temporal scales. The objective of this paper was to develop an estimating procedure of eventsoil loss from bare plots (length = 11–44 m, slope steepness = 14.9–16.0%) at two Italian sites, i.e. Masse,in Umbria, and Sparacia, in Sicily, having a similar sand content (5–7%) but different silt (33% at Sparacia,59% at Masse) and clay (62% and 34%, respectively) contents. A test of alternative erosivity indices for theMasse station showed that the best performances were obtained by the USLE-MM, originally developed atthe Sparacia station. This model includes an erosivity index equal to a power (exponent > 1) of the runoffratio, QR, times the single-storm erosion index, EI30. The fitted models at the two stations were found tocoincide for highly erosive events (i.e., QREI30 > 6 MJ mm ha−1 h−1). A parallelism of the two models wasdetected for low erosivity events. In conclusion, runoff was an important predictor of soil erosion, and localsoil characteristics had a more noticeable effect on soil loss for events with a relatively low soil detachmentand transport ability. A wider applicability of the USLE-MM scheme can be suggested than for the Sparaciastation alone. Additional testing of the model in other environments and development of accurate proceduresto estimate plot runoff coefficient at the event temporal scale are required.
|Numero di pagine||7|
|Stato di pubblicazione||Published - 2013|
All Science Journal Classification (ASJC) codes