The role of surface microreliefs in influencing splash erosion: A laboratory study

Abstract

The detachment and transport of soil particles from soil mass are important effects of falling raindrops on soil erosion during rainfall. The objective of this study was to determine whether soil microrelief affects the detachability and transportability of soil particles by raindrop splash. Experimental microreliefs were manually simulated by two tillage practices: shallow hoeing, contour chisel plowing, and a smooth slope served as control treatment. The experiment included three simulated rainfall intensities (1.0, 1.5, and 2.0 mm/min). A splash board was used to collect sediment splashed upslope as well as that splashed downslope. Results show that microrelief has a positive effect on detachment rate (DRt) and has a negative effect on net downslope movement rate (SPnet). With the exception of DRt of which hoe treatment was less than smooth at the rainfall of 1.0 mm/min intensity, DRt of hoe and chisel treatments were twice as high as that of smooth to other treatments. For all treatments, SPnet of hoe and chisel treatments were less than half of smooth. Regression analysis showed that DRt change with increasing rainfall intensity could be described by a power function for all treatments. The change of SPnet could be described by a logarithmic function for hoe and chisel treatments, while the change of SPnet of the smooth treatment could not be described by a logarithmic function. Statistical results suggest that DRt was significantly influenced by rainfall intensity, while SPnet was not. Conversely, SPnet was significantly influenced by soil microrelief, while DRt was not.

Keywords

• detachment rate
• soil erosion
• splash board
• raindrop impact