“…Indeed selective transportation of fine particles through surface and interrill flows enriched the sediment yield in fine particles and enhanced coarse particles in the eroded soil relative to the original soil (Foster et al, 1995). This result is in contradiction to previous observations that showed that on plot scale, silt and very fine sand are the most susceptible soil particle sizes to be detached and transported by water erosion processes (Wischmeier andSmith, 1978, Bonilla andJohnson, 2012). Although, clay minerals mostly improve soil aggregation in the semi-arid regions (Vaezi and Akbari, 2015), most of aggregates in the area are generally unstable due to the very low organic matter content (Vaezi and Abbasi, 2012).…”