COMPARISON OF IMPACT FORCES GENERATED BY DEBRIS FLOWS USING NUMERICAL ANALYSIS MODELS

Climate change has caused localized torrential rainfall and typhoons to occur more frequently, increasing the damage to both life and property. In particular, debris flows have caused damage not only in mountainous areas but also in urban centers. Many studies have been carried out about this, due to rising concern about debris flows. These studies applied different debris flow models and conducted analyses on the behaviors of debris flow as well as forecasting. Given this, however, the subject of the impact force of debris flows should also be taken into consideration. Thus, this study applied RAMMS and FLO-2D: two models used for the numerical analyses of debris flow to analyze impact force. In this paper, the selected study areas are Umyeonsan Mountain in Seoul and Majeoksan Mountain in Chuncheon, where damages on debris flows were caused by localized heavy rain in 2011. To identify a debris flow–triggering rainfall, we used and applied rainfall calculations carried out at different frequencies (30-year, 50-year, 100-year, 200-year). This study calculated and compared impact forces produced by the two models at any point in the study areas. Identifying impact forces based on the comparison of the two models will be useful in selecting materials and equipment appropriate when installing facilities in mountainous regions.