Evaluating Slope Stability Under Rainfall: The Role of Various Vegetation Types

Rainfall-induced shallow landslides affect nearly ۲۰% of the global land surface, playing a crucial role in both the hydrological and mechanical behavior of unstable slopes. In regions prone to geological hazards, understanding the hydrodynamic response of slopes covered with different vegetation types under rainfall conditions is essential. This study examines the hydraulic stability of soils with varying vegetation coverage during rainfall events and their subsequent impact on slope stability. To achieve this, soil-water characteristic curves and the stability of soil aggregates in three vegetation types were analyzed. A two-dimensional finite element model was employed to simulate slope stability under extreme rainfall scenarios with different durations.The results indicate that soils with trees retain higher matric suction and have more stable soil aggregates than those covered with shrubs or grass. Analysis of plastic strain distribution revealed that the highest deformation occurred at the toe of the slope. Furthermore, slopes with trees exhibited a shallower potential slip depth compared to those covered with shrubs or grass. Under both rainfall durations, the factor of safety (FoS) of tree-covered slopes varied by only ۰.۰۶, whereas the FoS of slopes with shrubs and grass fluctuated by ۰.۱. These findings provide critical insights into the influence of vegetation on slope stability under different rainfall intensities. The study underscores the importance of ecological strategies for mitigating mountain hazards and offers a scientific foundation for implementing effective land management practices, particularly in regions susceptible to rainfall-triggered landslides, such as mountainous terrains in Iran.

کلیدواژه ها:

precipitation ، vegetation types ، slope stability ، unsaturated soils ، soil aggregate ، matric suction