Comment on “Characterizing detachment and transport processes of
interrill soil erosion, Geoderma 376 (2020) 114549”
Abstract
Zhang et al (2020) measured soil splashed and washed by rain-impacted
flows on surfaces where 4 sections were exposed in sequence during a 1
hour rainfall event. In one treatment, upslope areas were protected by a
tarp, and in the other, protected by a gauze screen. Comparison between
the amounts splashed and eroded by the rain-impacted flow were used to
determine if detachment by surface water flows occurred. In this
comment, the conclusion that flow detachment occurred in all the screen
experiments and in all the tarp experiments on the 27 % slope and the
tarp experiment with 120 mm h-1 rain on the 18 % slope is shown to be
unsound for two reasons. Firstly, the conclusion is unsound because it
is well known that not all the material mobilized by raindrop impact is
lifted into that air and transported aerially over the surface in
raindrop splash. Secondly, the conclusion is unsound because the
equation used to determine apparent soil loss rates in the screen
experiments does not estimate the contribution of erosion in the
sections to the sediment discharged from the eroding surfaces.