School of Architectural Engineering, Yan??an University, Yan??an 716000, Shaanxi, China

 In order to clarify the influence of slope degree change on raindrop splash erosion characteristics of undisturbed loess, the self?designed test platform of artificial simulated raindrop splash erosion was used to carry out the experimental research on the evolution rules of undisturbed loess splash erosion under different rain diameters and intensities, and the correlation characteristics between the change of surface slope degree and the degree of soil splash erosion have been analyzed. The results show that the depth of splash pit increases exponentially with rainfall time, and gradually stabilizes after about 40 minutes. The splash erosion depth increases approximately linearly with the rain intensity. The rain diameter has a significant influence on the splash erosion range, the splash damage diameter and splash diffusion diameter increase with the increase of rain intensity, and the splash diffusion diameter D is about 2?? 0 ~ 3?? 5 times of the splash damage diameter D0 . As the slope degree increases, the shape of the splashing pit develops from an approximate “circle” to a “groove” along the direction of slope, while the depth of splashing pit decreases approximately linearly. The range of horizontal splash erosion decreases with the increase of slope degree, the splash erosion range of slope direction shows an increasing trend, and the splash damage range of slope direction is obviously larger than that of horizontal direction.