Effects of raindrop temperature on the contributions of slaking and mechanical striking to aggregate disintegration during splash erosion

The influence of raindrop temperature on the soil erosion process has been reported. However, the role of raindrop temperature in aggregate disintegration is unclear. The aims of this study are to investigate the effects of raindrop temperatures on soil aggregate disintegration and to evaluate their effects on the contribution of slaking and mechanical striking to splash erosion. Deionized water and ethanol (95%) were employed as raindrop materials to quantify the effects of raindrop temperature on the contributions of slaking and mechanical striking to splash erosion. Raindrop temperatures were set to 2 °C, 10 °C and 20 °C, and the rainfall heights were set to 0.5 m, 1.0 m and 1.5 m. The results showed that the splash erosion rate decreased with increasing temperature in the Loam1 and Loamy sandy. The breakdown rate decreased with increasing temperature in ethanol tests. The influence of temperature on slaking was greater than that on mechanical striking. The contribution rates of mechanical striking and slaking decreased and increased with increasing temperature, respectively. Slaking contributed more to aggregate disintegration at 10 °C and 20 °C, while mechanical striking was the primary contributor at 2 °C in the Loam2 and Loamy sandy. The results provided a deeper understanding of the mechanism of splash erosion and contributed to improving soil erosion prediction models.