Promoting effect of vegetation on the initiation of landslides induced by typhoon rainstorms

Vegetation is widely used to prevent landslides worldwide. However, rainstorm-induced landslides frequently occur on vegetation-covered slopes during the typhoon season in the southeastern coast of China. The results of a wind tunnel test reveal the effect of typhoon-induced loads on a slope through vegetation. Under a wind speed of 17m/s, the wind load can increase the sliding force by over 10%. Strong typhoon-induced loads cause the vegetation to exert a strong torque on the soil via roots, resulting in crack development. These cracks provide paths for rainwater infiltration and increase the soil permeability coefficient by over 10-fold when the typhoon passes. Therefore, special attention should be paid to the potential impacts of vegetation, especially large trees, on slope stability.