Promoting effect of vegetation on the landslide induced by typhoon rainstorm

Vegetation is widely used for preventing landslides around the world. However, an amount of rainstorm-induced landslides occurred frequently on vegetation-covered slopes during the typhoon season in the coast of Southeastern China. In order to investigate the effect of vegetation on the development of landslide under the condition of typhoon and rainstorm, the authors in this paper simulated the effect of wind load and vegetation swaying on stability of landslide through wind tunnel physical simulation tests. The results show that the load exerts on the slope by typhoon through vegetation shouldn’t be ignored. The wind load can increase the sliding force by more than 10% under super typhoon (with wind speed of 17 m/s). Meanwhile, the strong torque was loaded the on soil via the vegetation root, resulting in cracks in the soil. These cracks provide fast paths for rainwater infiltration, and the permeability coefficient of soil increased more than ten times later. Therefore, special attention should be paid to the potential implications of vegetation in the future, especially the high trees, which have disadvantages on landslides during typhoons.