Model Experiment Study on the Anti-Erosion Capacity of Loess Slope Considering Moss Biocrust Coverage and Slope Gradient

Abstract

Moss biocrusts play a significant role in enhancing the anti-erosion capacity of loess slope. The coverage of moss biocrusts and the slope gradient may be key factors controlling soil erosion on loess slopes. To investigate the ecological protection effect of moss biocrusts on loess slopes, this study conducted erosion experiments on loess slopes with different angles under moss biological crusts of various coverages. The controlled variables included moss biocrust coverage rate and slope angle. The moss biocrust coverage rates were 0%, 30%, 60%, and 90%, while the slope angles were 30°, 45°, 60°, and 75°. The results show that moss crusts can delay the initiation of runoff, hinder the velocity of runoff and sediment transport, and utilize their spring-like form to reduce the impact force of raindrops on soil particles. Compared to bare soil slopes, slopes covered with moss crusts exhibit significantly reduced erosion damage areas and significantly lower sediment yield (0.0963 kg·m^-2-43.7185 kg·m^-2). Considering the combined effects of crust coverage and slope steepness, this study preliminarily established a soil erosion equation based on moss crust coverage and slope gradient: z = -0.4102 + 0.0119x + 0.3991exp(-0.7060y). When the crust coverage reached a critical threshold of 60%, the improvement in slope erosion resistance reached its maximum, after which the rate of improvement gradually declines. The research findings provide crucial reference data for promoting the application of moss biocrusts in the Loess Plateau region to implement sustainable soil and water conservation practices and strengthen ecological slope protection.