南部板岩地質區地震及豪雨誘發山崩之地形特徵－以隘寮溪流域為例

Topographic Characteristic of the Landslide Induced by Earthquake and Rainfall in Slate Stratum in South Taiwan-Case of Ai-Liao Catchment

10.6574/JPRS.2014.18(2).2

陳天健(Tien-Chien Chen)；李明熹(Ming-Hsi Lee)；曾勛苑(Xun-Yuan Zeng)；顏宏諭(Hong-Yu Yen)；李宗聯(Zong-Lian Li)；林意修(Yi-Siou Lin)

山崩 ； 地震 ； 颱風 ； 板岩 ； 地形 ； Earthquake ； rainfall ； landslide ； slate ； topography

航測及遙測學刊

18卷2期（2014 / 05 / 01）

79 - 92

繁體中文

本文以台灣南部高屏溪支流之隘寮溪流域為研究區，應用GIS結合航照、災前後DEM或光達數值地型，就集集地震與莫拉克颱風事件之二千多筆崩塌地，進行地震及豪雨誘發山崩地形特性研究。成果顯示地震之崩塌坡度主要分佈於30-50度，75%位於山脊或山腹，90%崩塌之面積小於10公頃；而颱風之崩塌坡度則主要分佈於20-40度，81%位於山腹或坡趾，且中大型崩塌面積明顯增多，52%崩塌之面積大於10公頃；颱風引致大型崩塌之數量較地震事件顯著。就地形分析方面，斜交坡地形之崩塌趨勢為最；大型崩塌地之曲率達1×10^(-4)時，崩塌顯著增加。大型崩塌地滑動前，坡體均已具某種程度之撓曲變形，顯示大型崩塌呈漸進式變形，其地形曲率隨時間逐漸增大，最終乃至坡體快速滑動。

The paper draws the topographic characteristics of the landslide induced by Chi-Chi Earthquake and Typhoon Morakot in Ai-Liao catchment, in slate stratum. The result from topographic analysis on the DEM shows 90% landslides induced by earthquake are small than 10 ha, the average slope is 30-50°, and 75% of landslide locates at the ridge or the mountainside of the slope. Oppositely, the 52% landslides induced by typhoon are large than 10 ha, the average slope of landslide is gentle to the one of earthquake landslides and 81% of landslides locates at the mountainside or the toe of slope. The analysis result also demonstrated that a certain degree of deflection usually occurs before a sliding initiation that suggests the deformation (and the subsequent damage) of the massive landslide is progressive. Moreover, the profile curvatures of landslide cases are close to the curvature 1×10^(-4) (1/m), the landslide possibility rises up at where curvature beyond the value.