Landslides are one of the main reasons for the soil erosion of a watershed and increases in sediment yield. To explore the effects of landslides on soil erosion and sediment yield, a physiographic soil erosion–deposition model was used in conjunction with a Geographic Information System to simulate soil erosion and sediment yield caused by the typhoon rainfall events and heavy rainfall. The results indicated that the soil erosion and sediment yield
of landslide areas were both significantly higher than those of areas without landslides by 1.1-7.7 and 1.3-9.1 times,
respectively. The trend of increasing soil erosion and sediment yield is consistent with change in the trend of the landslide ratio in the watershed. Although the distribution of soil erosion areas had a similar trend in areas influenced and not influenced by landslide, the depth of erosion in landslide areas was more severe. According to area statistics on erosion depth, compared with the area without landslide, the area of erosion depth of <0.5 cm is reduced; landslide ratio and erosion depth increase with an increase in accumulated rainfall. The total area of erosion did not increase, but the erosion depth increased. The results from the study will aid management units in the development of reference adaptation strategies.
Key Words: Landslide Ratio, Physiographic Soil Erosion–Deposition Model, Soil Erosion, Sediment Yield