台東地區土砂災害之生態環境脆弱度評估

Assess Eco-environmental Vulnerability of Debris Disaster Areas in Taitung County

陳桂嘉(Kuei-Chia Chen) ； 吳守從(Shou-Tsung Wu) ； 陳朝圳(Chaur-Tzuhn Chen)

《航測及遙測學刊》 15卷1期 (2010/03) Pp. 51-64

https://doi.org/10.6574/JPRS.2010.15(1).4

摘要

知本溪與太麻里溪爲台東縣較嚴重的莫拉克颱風土砂災害集水區，崩塌是該集水區內最嚴重的土砂災害類型。本研究目的在於發展土砂災害集水區的生態環境脆弱程度評估模式。研究方法係整合GIS與RS技術，利用因素分析求解崩塌地影響因子權重，並以環境脆弱度指標，評估集水區生態脆弱區域，同時建構以自然環境潛在因子，以及保全對象危害度因子爲基礎的崩塌地復育需求模式，並利用莫拉克颱風造成的崩塌地區作爲脆弱度區域之驗證。研究結果顯示，除了環境區位因子的干擾外，人爲開發亦爲崩塌地發生的重要影響因子；在脆弱度分析方面，兩個集水區均顯現崩塌地確實是處於高危險且高脆弱之地區，其中又以太麻里溪集水區最爲嚴重，整個區域內被歸類於極脆弱等級之崩塌地高達41.35%。依據本研究所建立的崩塌地復育需求評估模式，顯示太麻里溪集水區崩塌地有較高的復育處理需求，因此研究結果有助未來集水區進行治理及崩塌地植生復育之參考。

關鍵字

生態環境脆弱度 ； 土砂災害 ； 植生復育評估 ； 集水區 ； 莫拉克颱風

並列摘要

Among the watersheds in Taitung County, the river watersheds of Zhiben and Taimali are more serious natural disaster areas on typhoon Morakot, in which landslide is the most serious type of sediment disasters in those watersheds. The purpose of this study was to develop a model of eco-environmental vulnerability for the landslide disaster watershed. First, we used the factor analysis to get the weights of landslide causing impact factors. After this, we used environmental vulnerability index (EVI) to assess the eco-environmental vulnerable area of watershed. We also created the assessment model of vegetation recovery that was based on the natural potential environmental factors and the protected object factors. Finally, we used the disasters areas which Morakot created to confirm the frailty region the accuracy. The results indicated that not only landslide occurred was base on the watershed environment at factors, the impact of human activity was also an important factor in these two watersheds. In vulnerability of this study indicated that the landslides were located in high-risk and high-vulnerability areas. Especially, Taimali river watershed was the gravest, and there was 41.35% of landslide belonging extreme level. According to the landslide vegetation recovery assessment model, the First Score (FS) was know that landslide of Taimali river watershed is necessary to give the precedence action. This research can give the guideline of vegetation recovery in future.

並列關鍵字

Eco-environmental vulnerability ； Debris Disaster ； Vegetation recovery assessment ； Watershed ； Typhoon Morakot