On the Characteristics of Yucheliao Landslide inTaiwan by Remote Sensing and Numerical Simulation

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In August, 2009, the Typhoon Morakot hit Taiwan and induced many landslide hazards. An induced landslide event happened near the Yucheliao settlement, Meishan town, Chiayi county, Taiwan. According to data and research after Typhoon Morakot, slopes near Yucheliao are considered as potential region for deep-seated landslide. In this study, the characteristics of the Yucheliao Landslide event is examined with the particle image velocimetry (PIV) analysis and numerical simulation. The PIV results show that the landslide block slipped southwardly after triggered. The block slip is 40 m averagely in horizontal distance, and the maximum slip is 60 m. However, the inaccuracy of the results occurs in the PIV analysis due to severe change in land cover and large interrogation window size. From the numerical simulation, it is estimated that both the slope with homogeneous rock and slope with layered rock are more stable than the slope with pre-existing slip surface. The slip surface could be roughly interpreted by surface displacement with numerical modeling, but the depth and geometry have obvious differences from real situation. By considering the underground deformation of the landslide, the accuracy of interpreting potential slip surface could be improved when other approaches are applied.