莫拉克颱風引致吉露部落崩塌之案例研究

Case Study of Ji-Lou Landslide Triggered by Typhoon Morakot

鍾明劍(Ming-Chien Chung) ； 譚志豪(Chih-Hao Tan) ； 王金山(Gin-Shan Wang) ； 冀樹勇(Shu-Yeong Chi) ； 蘇泰維(Tai-Wei Su)

《中華水土保持學報》 41卷4期 (2010/12) Pp. 333-342

https://doi.org/10.29417/JCSWC.201012_41(4).0005

摘要

莫拉克颱風不僅在台灣南部地區造成嚴重水患，連日豪大雨更誘發許多大型山崩與土石流災害，造成重大傷亡及經濟損失，其中位於隘寮北溪中游河床傾斜台地的吉露部落，因下邊坡區域產生嚴重崩塌災害，災後即被評定為不安全部落而全體遷村。本研究利用莫拉克颱風期間之降雨量、地下水位等資料，結合降雨入滲－地下水滲流－穩定性－變形性之串聯式分析模式，模擬吉露部落受豪雨引致下邊坡崩塌的機制。研究成果顯示莫拉克颱風前吉露部落下邊坡區域的安全係數為1.57，然於莫拉克颱風期間降低至0.97達到破壞條件。透過現地監測數據及現勘成果比對，可證實本研究所提分析模式具有良好的模擬能力與正確性，研究成果可供往後崩塌地在預測雨量下穩定性評估之參考。

關鍵字

崩塌 ； 莫拉克颱風 ； 吉露部落

並列摘要

Typhoon Morakot brought tremendous rainfall to southern Taiwan. It caused many villages and towns to be flooded in low-lying areas as well as numerous landslides and debris flows in mountainous areas. Therefore, the disaster resulted in severe casualties and property damage. This paper presents a case study of Ji-Lou landslide triggered by Typhoon Morakot. A series of hydrogeological investigations, in-site tests, and laboratory experiments were carried out to establish the hydrogeological conceptual model of Ji-Lou. Coupled analysis of rainfall, infiltration, seepage, slope stability, and slope deformation was used to estimate the slope stability of Ji-Lou tribe during Typhoon Morakot. For the active landslide analysis, a two-dimensional numerical program, GeoStudio, was employed to perform the modeling practice. The results show the F.S. of Ji-Lou tribe reduced from 1.57 to 0.97 during Typhoon Morakot. In addition, the results of coupled analysis demonstrated good agreement between the predicted results and the data from field monitoring of the typhoon event. Further, it is expected the landslide initiation, enlargement, and reactivation can be more confidently predicted through using the aforementioned physics-based models.

並列關鍵字

landslide ； Typhoon Morakot ； Ji-Lou tribe