Multi-level systematic analysis of sheet erosion mechanism on steep
slopes covered by grass
Abstract
The erosion mechanism on steep grass slopes is the basis and difficulty
of grassland erosion model, but few related studies.The erosion
mechanism on steep slopes covered by grass was studied by artificial
rainfall experiments. Results showed the following: (1) The
contributions of the Rω(reduction of stream power) and RK(reduction of
soil erodibility) to the decreasing erosion modulus (REM) are 61.02%
and 33.55%, respectively, totalling to 94.57%. This finding indicates
that herbaceous vegetation decreases the interrill erosion mainly by
decreasing the stream power.(2) The relationship between the Rω and
grass cover, and phytyl cover can be described with logarithmic
equations.The calculation under different rainfall intensities or slopes
showed contribution rates of 82.86%-97.51% or 86.36%-97.51%, and
1.48%-14.82% or 1.48%-20.44%. (3) The relationship between the RK
androot volume (RV), and soil bulk density (SD) can be described with
binary logarithmic equations.The calculation showed contribution rates
of 73.61%-97.94, and 0.04%-0.22%. (4) In-depth analysis found the
regulation effect of grass on stream power is mainly achieved by grass
cover, and the regulation effect of grass on soil erodibility is mainly
achieved by root volume. The research focus should be on the impact of
vegetation layout, vegetation types, vegetation density, and soil
properties on soil erosion under large-scale conditions.