Few data are available for estimating the sediment transport rate on a
steep slope of grass with different covers. In this study, the
artificial simulated rainfall test is used to investigate how rainfall
intensity, slope and cover affect the sediment transport rate.
Simultaneously, the study establishes a model for the sediment transport
rate using shear stress, stream power, unit stream power and unit energy
on steep grassland slopes. Results show that the sediment transport rate
decreases as the vegetation cover increases, as described by linear or
logarithmic equations under different rainfall intensities or slopes.
The sediment transport rate increases as an exponential function
equation with rainfall intensity, slope and cover with a Nash–Sutcliffe
model efficiency (NSE) value of 0.864. The effects of slope steepness
are stronger than the effects of rainfall intensity and cover.
Regression analyses show that the sediment transport rate can be
predicted from the power function equations of shear stress, stream
power and unit energy. In addition, the sediment transport rate can be
fit to unit stream power with linear equation (NSE = 0.840). Further
analysis shows that the sediment transport rate is best modelled by a
power function equation that includes three factors, i.e. rainfall
intensity, vegetation cover and slope.The measurements and calculations
of the sediment transport rate, the calculations of the surface
roughness and characteristic considerations of the vegetation for sheet
flow should be explored in future research, which are important in
improving experimental accuracy and sediment transport rate modell