應用遙測技術監測澎湖銀合歡擴散之研究

Application of Remote Sensing on Monitoring the Dispersal of Leucaena Leucocephala in Penghu Area

10.30064/QJCF.201103.0011

陳奐潣(Huan-Min Chen)；羅漢強(Hann-Chung Lo)；鄭祈全(Chi-Chuan Cheng)；吳治達(Chih-Da Wu)

遙測 ； 地景指數 ； 銀合歡 ； 擴散 ； 物種入侵 ； Remote Sensing ； Landscape Indices ； Leucaena leucocephala ； Dispersal ； Species Invasion

中華林學季刊

44卷1期（2011 / 03 / 01）

133 - 144

繁體中文

本研究旨在應用遙測技術監測澎湖地區銀合歡之擴散變遷情形。研究過程係利用1993和2005年SPOT-2衛星影像，經影像分類處理以獲取澎湖地區之土地使用圖和銀合歡空間分佈圖，並採用檢核區方式評估其分類準確度；之後，利用地景指數分析澎湖地區的地景結構及銀合歡的空間分布特性，並監測其擴散變遷情形。研究結果在影像分類方面，澎湖地區的土地使用型分爲銀合歡、草生地、農地、水域、造林地、聚落與裸露地七類，其1993年和2005年之整體分類準確度分別爲88.74%和86.94%。至於在地景結構和銀合歡擴散監測方面則發現，澎湖地區銀合歡從1993年到2005年確實有逐漸擴散的趨勢，並有入侵其他土地使用型的情形，該擴散情形經Shannon多樣性t檢定法檢定後亦顯示銀合歡的擴散已對澎湖地景造成顯著的影響，因此，相關單位應及早預防銀合歡的過度擴散，做好監控與防治措施，避免銀合歡擴散造成澎湖地區的生態失衡。

The objective of this study focuses on the application of remote sensing on monitoring the dispersal change of Leucaena leucocephala in Penghu area. The research processes include using SPOT-2 images from 1993 and 2005 to generate the land-use map of Penghu area and spatial distribution map of Leucaena leucocephala, and then assess the accuracy of classification map according to the selected test areas. The quantified landscape indices (e.g., number of patch, Shannon diversity index, shape index) are then calculated for analyzing Penghu's landscape structure, spatial distribution and dispersal change of Leucaena leucocephala. The results obtained from image classification indicated that the study area was classified into six categories (i.e., Leucaena leucocephala, grassland, farmland, water, forest, and building). The overall classification accuracies for 1993 and 2005 land-use maps are 88.74% and 86.94% after the assessment of test area. As for the analysis of landscape structure and dispersal monitoring, the result shows that the dispersal trend of Leucaena leucocephala increases from 1993 to 2005, which has also affected other surrounding land-use types. Besides, Shannon diversity t-test has been applied to further investigate the dispersal effect on Penghu's landscape. The result did show a significant effect. Therefore, the result obtained from this study can be a reference for the related forest management units to prevent from over dispersal of Leucaena leucocephala.