SPOT 衛星影像之崩塌地自動分類研究

Automatic Classification of Landslides on a SPOT Image

劉守恆(Shou-Heng Liu) ； 林慶偉(Ching-Weei Lin)

《航測及遙測學刊》 9卷2期 (2004/06) Pp. 9-22

https://doi.org/10.6574/JPRS.2004.9(2).2

摘要

本研究主要探討使用單幅SPOT衛星影像資料進行自動辨識崩塌地的可行方法，並分析其適用性與準確度；同時以地震前後多時期SPOT衛星影像資料進行崩塌地自動判釋，分析921地震事件對於濁水溪流域內崩塌地發育之影響。
一般影像自動判釋工作常以影像之分類法來完成，本研究經由理論方法的計算，發現在研究區域內以航空照片判釋所得之崩塌地為比對的基準下，以SPOT影像資料為基礎的分類法其生產者與使用者準確度之平均值可達到70%，但是在實際應用上卻與理論值有20%~40%的誤差，無法滿足實際應用的要求。
本研究中利用SPOT影像波段3與波段2之比值進行比值轉換處理可有效提升判釋之準確度，分類後生產者準確度可提高到50%。並用坡度因數將坡度小於10度之非崩塌地濾除，可以進一步提升生產者準確度到76%。此外，研究中還對崩塌面積及不同坡度分佈下的判釋準確度變化進行探討。綜合分析的結果，以衛星影像進行崩塌地自動判釋不但分析迅速，又具有相當的實用性，確實為一項研究坡地相關災害的有力工具。

關鍵字

崩塌地 ； 自動分類 ； SPOT衛星影像

並列摘要

The main purpose of this study is to evaluate approaches of automatic classification for landslide on a SPOT image. Additionally, 8 SPOT images that taken from 1996 to 2001 were used to understand the impact of the Chi-Chi Earthquake on the occurrences of landslide in the Choushuichi watershed.
Compared to the interpretation of aerial photos, theoretical calculation shows that the average of producer's and user's accuracy in automatic classification of landslide can reach 70%. However, in comparison with theoretical calculation, 20-40% errors can be produced when we apply these techniques. In this study, the producer's accuracy can be increased to 50% when the ratio of band 3/band 2 is applied in vector image transformation. Besides, the produce's accuracy can further significantly be increased to 76% if the hill slope is used as a filter to delete the areas with similar characteristics as landslides when its slope is less than 10°. Although the accuracy of automatic classification of landslides in a SPOT image is still less than that identified from aerial photos, it is a fast, economic, and powerful tool to continuously monitor occurrences of landslides.

並列關鍵字

landslide ； automatic classification ； SPOT image