Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/34141
標題: 九份二山崩塌區位植生復育與堰塞湖淤滿年限之研究
A Study of Vegetation Recovery in Chiufenershan Landslide Area and Life Span of Landslide-dammed Lakes
作者: 許銘峰
Hsu, Ming-Feng
關鍵字: landslide area;崩塌區位;landslide-dammed lakes;vegetation recovery;堰塞湖;植生復育
出版社: 水土保持學系
摘要: 
Large-scale landslide, caused by the catastrophic 921 earthquake, occurred nearby the foot of Kan-Dou mountain at Guoshing township in Nantou. Two landslide-dammed lakes were formed at the Chiutsaihu and Satsikeng creek respectively. Areas of denudation are urgent to be restored for secondary disaster prevention in the following rainy seasons. Satellite images and digital terrain model(DTM) were used to process the vegetation index analysis for identifying landslide sites and to extract topographic information of the areas. This research applies information of DTM and satellite images to monitor and/or assess vegetative restoration ratio for the landslide. The functions of site analysis, dynamic watershed query, revegetation monitoring, sediment yield and life span evaluation of the landslide-dammed lakes in Chiufenershan watershed are all integrated in this study
Vegetation analysis show that there exists a good trend of vegetation recovery (C factor changing from 0.79 to 0.47 and VRR=59.9%) at the landslide sites. The better restorative sites are located at the filling areas with elevation of 500-700m, gentle slope (< 30%), no obvious aspect. The worse sites are at areas of dip slope with elevation of 700-900m, east and/or southeast aspect.
The estimated life spans of Satsikeng and Chiutsaihu landslide-dammed lake are 12-18 years and 10-16 years. The corresponding annual watershed erosion depth is 0.92cm and 1.38cm, which are derived from USLE and sediment delivery ratio at watershed scale.

921集集大地震造成南投縣國姓鄉崁斗山山麓一帶大規模的崩塌,於韭菜湖溪及澀仔坑溪形成兩處堰塞湖,為防止崩塌土體受雨水沖刷並減免其危及下游地區民眾的生命財產安全,崩塌區位之植生復育及防災工作極為重要。本研究利用數值地形模型及衛星影像資料,萃取集水區之地文與水文資訊,並針對崩塌區位進行植生復育監測,量化分析崩塌區位之植生復育指標,探討植生復育之影響因子。另由集水區泥砂遞移率及土壤流失量之推估,以計算堰塞湖集水區泥砂產量,作為堰塞湖淤滿年限之推估。
經以植生覆蓋因子(C值)與植生復育率進行探討崩塌區位之植生復育情形,結果顯示平均C值已從地震後之0.79逐漸回復至0.47,而崩塌區位之平均植生復育率也已提高至59.9%,表示崩塌區位之植生復育情形已有良好之效果。復育較佳之區位多在高程500~700m之堆積區域,坡度在30%以下,而坡向則較無顯著之現象。但植生復育較差之坡向多分佈在東及東南向之順向坡;而高程多在700~900m之間。
利用兩處堰塞湖上游集水區之土壤流失量所推估之泥砂產量及堰塞湖容積,以估算堰塞湖淤滿之年限及集水區沖刷深度,結果顯示:澀仔坑堰塞湖淤滿年限約為12~18年,集水區年平均沖刷深度約為0.92 cm/yr;韭菜湖堰塞湖淤滿年限約為10~16年,集水區年平均沖刷深度約為1.38 cm/yr。
URI: http://hdl.handle.net/11455/34141
Appears in Collections:水土保持學系

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