A Study of The Impact of Landslides on The Occurrence Debris of WatershedFlows: An Example from Ai-Liao River
| Autor: | Chi-JenTsai, 蔡啟仁 |
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| Rok vydání: | 2010 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 98 In this study, by using the concept of stream order and working in the platform of geographic information system (GIS),six periods of FORMOSAT 2 images taken from 2005 to 2009 that covered four typhoon events are used to identify landslides and debris flows in the Ai-Liao River watershed. In the images taken after the Typhoon Bergonia in 2005, 638.38 ha landslides was recognized. Additionally, 604.08 ha induced by the Karmeigi in 2008, 478.31 hectares triggered by the Typhoon Sinlarku in 2008 and 4324.05 hectares landslides are induced by the Morakot in 2009. For debris flows triggered by the Bergonia, Karmeigi and Sinlark, there are 26 debris flows in gullies with a stream order 1, 13 in gullies with a stream order 2, 6 in gullies with a stream order 3, and 4 in gullies with a stream order 4. For the Typhoon Morakot, there are 91 debris flows to be recognized in gullies with a stream order 1, 101 in gullies with a stream order 2, 53 in gullies with a stream order 3, and 20 in gullies with a stream order 4. For all events, most of debris flows were recognized to occur in slate belt. In addition, compared to the gullies without debris flows, the landslide density in the catchments of gullies with debris flow is significantly higher than that without debris flows. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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