Hydrological and mechanical effects of vegetation on slope stability

Abstract

Hydrological and mechanical effects of vegetation with different root characteristics on shallow slope stability are investigated in the study. Vegetation with more roots concentrated on the soil surface has prominent effects on slope stability than uniform distributed roots. The relative importance between the hydrological and mechanical effects on slope stability mainly depends on root architecture, transpiration rate, root diameter, slope angle, and soil type. At drying conditions, mechanical effect of roots is more important in slopes with larger inclination angle, while it is the opposite for the hydrological effect. In humid areas (i.e. transpiration rate < 2 mm/day), the mechanical effect of roots dominates slope stability. After rainfall, the hydrological effect of root vanishes almost entirely inside root zone, so hence the enhancement of slope stability within root zone mainly relies on the mechanical effect of roots. The coarse-grained soil should be planted with vegetation to prevent soil shallow slope failure.