Abstract：In order to reveal the raindrop splash erosion characteristics and evolution process of loess in Yan'an hilly region, the authors selected the soil of Late Pleistocene as the research object, and used self-made raindrop simulation test device with controllable rain diameter and rain intensity to conduct the raindrop splash erosion test on the raw loess collected from the shallow surface of the slope and investigate the influence law of rainfall intensity and rainfall duration on the erosion characteristics of loess. The results show that an approximately circular spattering pit is gradually formed on the surface of undisturbed loess under the continuous impact of raindrops, and the pattering pit changes from shallow to deep and from small to large. The development process of erosion depth with different rainfall duration can be described as rapid growth stage (0-10 min), slow growth stage (10-40 min) and stable development stage (40-60 min). The development of erosion depth, erosion damage diameter and erosion diffusion diameter with different rainfall duration showed a power function growth trend, and 0-10 min is the main growth stage of erosion deformation. The greater the rainfall intensity is, the more significant the soil erosion is. The erosion depth of 0-10 min accounted for more than 81% of the total erosion depth, and the lateral erosion range on the splash surface is stabilized gradually after the rainfall lasted for about 10 minutes. The erosion depth, erosion damage diameter and erosion diffusion diameter are positively correlated with rainfall intensity, and the erosion diffusion diameter D is about 2.71-3.55 times the erosion damage diameter D0. The heavy rainfall is an important factor that induces erosion disasters and water and soil erosion on loess slope, so the it is recommended to take protective measures to enhance the slope anti-erosion ability, including green planting, reinforcement and waterproof and drainage, which can reduce the occurrence of shallow water erosion disaster on loess slope. This research can provide reference for rainfall erosion disasters in loess region.
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2023, Vol. 10 
