| dc.description.abstract | Landslides, which result in numerous casualties and significant property losses, are a major natural disaster in Taiwan. Traditional landslide studies focused on heavy rainfall, geological condition and topographical condition as trigger factors, often overlooking the impact of strong winds. However, typhoons often bring intense wind gusts that can severely sway trees, leading to the soil disturbance which decreasing the slope stability. Additionally, some landslide events occurred on broad-leaved forest along the slopes where were primarily affected by strong winds of the typhoon rather than its heavy rainfall.
We examined the significance of the combined rain-wind influence on landslides by Three-dimensional (3D) Histogram and Mann-Whitney U test. The Mann-Whitney U test results reveal that wind and rain conditions are both significant differences at a significant level of P≤0.001 between typhoon-induced landslide events and non-landslide events. And 3D Histogram results demonstrate a positive skewed distribution similar to the rainfall direction in strong wind duration axis, which implies that the probability of landslides occurring increased with an increase in the duration of strong wind. Furthermore, we construct machine learning Random Forest models based on factors, such as heavy rain, strong wind, traditional geological conditions, and topographical factors. The model that includes strong wind factors shows better accuracy than the model that does not include strong wind factors. Therefore, apart from heavy rainfall, strong wind is also one of the important factors that may increase or trigger the risk of landslides. Ignoring the effect of strong wind when investigating typhoon-induced landslides might lead to severe damage. | en_US |