以多期遙測衛星影像監測臺大實驗林溪頭營林區三處崩塌地災害

Monitoring the Change of Three Landslide Sites in Sites Tract of NTU Experimental Forest by Using Multi-temporal Satellite Images

衛強(Chiang Wei)

《國立臺灣大學生物資源暨農學院實驗林研究報告》 20卷1期 (2006/03) Pp. 1-12

https://doi.org/10.6542/EFNTU.200603_20(1).0001

摘要

本研究利用不同時期之多光譜SPOT衛星影像，結合地理資訊系統之空間圖資、航照圖、地表高程模式等資料，藉由衛星影像資料建立不同之植生指標監測臺大實驗林溪頭營林區內之崩塌地復育情形。研究樣區選定溪頭營林區二林班杉林漢公路旁狗彎、大學坑及四林班內湖國小旁三處崩塌地。研究中使用影像波段比、常態化差異植生指標、綠度指數、亮度指數四項指標來評估崩塌地復原之狀況。經分析三個樣區之四項植生指數，波段比、常態化差異植生指標與綠度指數在進行人工或自然復育後均呈現增加之趨勢；亮度指數則呈現下降之趨勢。而植生剩餘率與921地震前相較，顯示在歷經921地震及桃芝颱風等後續災害，經相關單位進行崩塌地緊急水土保持處理工程後，崩塌地與裸露地已逐漸呈現穩定狀態，植生復育情形良好。本研究利用遙測衛星資料與地理資訊系統資訊，輔以地面實際探勘資料佐証，可有效提供林業管理單位進行崩塌地區變遷監測與管理，並作為未來復育造林之參考。

關鍵字

SPOT衛星影像 ； 崩塌地 ； 植生指標 ； 變遷偵測

並列摘要

Multi-temporal satellite images are used to locate and monitor the changes of landslides by combining the GIS spatial coverage, air photo and DEM data in this study. Vegetation Indices (VI) derived from satellite image are analyzed for the recovery condition of landslide areas. Band Ratio (BR), Normalized Difference Vegetation Index (NDVI), Greenness Index (GI) and Brightness Index (BI) of three test sites located in Sitou Tract are analyzed to evaluate the recovery condition. The result shows that after the remediation by the authorities, the landslide areas and bare land caused by Chi-Chi earthquake and following typhoons remain stable and the Vegetation Remnant Rate (VRR) is also satisfactory. BR, NDVI and GI increase after the natural recovery and artificial remediation; on the contrary, BI decreases. The result indicates that proposed technique combined with remote sensing technology and actual ground survey can efficiently monitor and manage the landslides in forestland, and it also can serve as the future reference for forest administration.

並列關鍵字

SPOT satellite imagery ； landslides ； vegetation index ； change detection