Case Study of Ji-Lou Landslide Triggered by Typhoon Morakot

摘要

Typhoon Morakot brought tremendous rainfall to southern Taiwan. Itrncaused many villages and towns to be flooded in low-lying areas asrnwell as numerous landslides and debris flows in mountainous areas.rnTherefore, the disaster resulted in severe casualties and propertyrndamage. This paper presents a case study of Ji-Lou landslide triggeredrnby Typhoon Morakot. A series of hydrogeological investigations, insiterntests, and laboratory experiments were carried out to establish thernhydrogeological conceptual model of Ji-Lou landslide. Coupledrnanalysis of rainfall, infiltration, seepage, slope stability, and sloperndeformation was used to estimate the slope stability of Ji-Lou landslidernduring Typhoon Morakot. For the active landslide analysis, a twodimensionalrnnumerical program, GeoStudio, was employed to performrnthe modeling practice. The results show the F.S. of Ji-Lou landslidernreduced from 1.57 to 0.97 during Typhoon Morakot. In addition, thernresults of coupled analysis demonstrated good agreement between thernpredicted results and the data from field monitoring of the typhoonrnevent. Further, it is expected the landslide initiation, enlargement, andrnreactivation can be more confidently predicted through using thernaforementioned physics-based models.