| dc.description.abstract | In the regions neighboring the Xinwulu River, flowing along the eastern part of the Southern Cross-Island Highway, high uplift and erosion rates were calculated in previous studies. Landslides and debris flows, often following heavy rain, occur on slopes near the highway, causing damages of life. In this study, we used aero photos, digital elevation models, field investigations and slope stability analysis to study how geologic structures and materials on slopes affect the slope instabilities along the section of the highway between Xiangyang and Chulai, trying to find out the ways landslides might occur.
In our study area, instable slopes are categorized into three types: 1) combinations of the attitude of geologic structures and slopes in bedrocks causing instable slopes; 2) slopes composed of poorly cemented materials; 3) fractured rocks affected by shear zones or faults. According to our observations and analyses, most landslides are developed along major faults or shear zones. In Xinwu and Lidao, the positions of landslides form linear patterns, corresponding with the shear zones. Landslides are generally facing southeast in this area, coinciding with dip directions of most faults and shear zones. While considering the lithology, few landslides are distributed along the area majorly consisting of schists between Xinwu and Wulu, whereas most of these features are developed in sandstone beds interlayered with slates or phyllites. Thus, we conclude that the distribution of landslides is highly related to geologic structures and lithology along the Southern Cross-Island Highway. The results provide us a concept which can be applied to hazard evaluation and prevention in the future. | en_US |