Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/33942
標題: 烏溪流域植生復育評估系統與降雨逕流模式建置之研究
Establishment of vegetation recovery assessment system and rainfall-runoff model in Wu River Basin
作者: 宋之光
關鍵字: Normalized difference vegetation index;常態化差異植生指標;Vegetation recovery;Landslides;Rainfall-runoff model;植生復育;崩塌地;降雨-逕流模式
出版社: 水土保持學系
摘要: 
中文摘要
烏溪流域位於台灣中部,在經歷九二一集集大地震後產生多處崩塌地,在暴雨期間易造成二次災害,本研究利用常態化差異植生指標(Normalized Difference Vegetation Index; NDVI)量化分析烏溪流域崩塌區位及其植生復育情形,並建置集水區崩塌地植生復育評估系統,作為崩塌地監測之用;另以地理統計推求降雨資料之空間分布配合等集流時間概念修正合理化公式之限制,透過實測流量資料分析推求流域內上、中、下游監測站降雨-逕流歷線之修正值α (洪峰到達時間修正係數)、β (洪峰值修正係數)及退水修正式R,建置集水區降雨-逕流模式。
研究結果顯示九份二山、九九峰崩塌區位於地震後三年之植生復育率有逐年改善之趨勢,九份二山復育率分別為2000年22.9%、2001年37.7%及2002年58.5%,九九峰復育率分別為2000年27.1%、2001年40.3%及2002年52.4%。
由模擬結果可知,集水區降雨-逕流模式之修正係數α與集水區最大降雨強度成負相關,β則與集水區洪峰前累積雨量成正相關;若以不同時期之植生覆蓋狀況予以推估,可得地表逕流量將隨著植生復育改善而降低。
(關鍵詞:常態化差異植生指標、植生復育、崩塌地、降雨-逕流模式)

ABSTRACT
The 921 Chichi Earthquake resulted in lots of landslides in Wu River basin. Satellite image and digital terrain model were used to process the vegetation index analysis for identifying landslide sites and extracting topographic information in this study area.
A system coupled with GIS developed in this research has been effectively used to monitor and/or assess the recovery rate of vegetation for the landslides. Peak flow estimation and hydrograph simulation by the rainfall-runoff model were employed to analyze affecting parameters for flood events.
The correction coefficient (α,β) and the revised recession curve (R) calibrated from the observed data can be as the index of watershed characteristics. The correction coefficient α-value represents water conservation capability; the β-value can be employed as the index of sediment concentration in the runoff.
Vegetation analysis show that there exists a good trend of vegetation at the landslide sites of Chiufenershan (VRR= 22.9% in 2000, 37.7% in 2001, 58.5% in 2002 respectively) and Ninety-nine peaks(VRR= 27.1% in 2000, 40.3% in 2001, 52.4% in 2002 respectively) areas. Simulations shows that there is a negative correlation between α-value and the maximum rainfall intensity while a positive correlation between β-value and cumulative rainfall before peak flow. Better vegetation recovery rate results in less surface run-off in the watershed according to the model simulation in this study.
(keywords: Normalized difference vegetation index, Vegetation recovery, Landslides, Rainfall-runoff model)
URI: http://hdl.handle.net/11455/33942
Appears in Collections:水土保持學系

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