以MODIS植生指標監測森林健康

Using Modis Vegetation Indices to Monitor Forest Health

沙學均(Hsueh-Chun Sha) ； 魏浚紘(Chun-Hung Wei) ； 劉宜婷(Ying-Ting Liu) ； 陳朝圳(Chaur-Tzuhn Chen)

《中華林學季刊》 45卷1期 (2012/03) Pp. 109-120

https://doi.org/10.30064/QJCF.201203.0009

摘要

台灣地區森林覆蓋面積約佔陸域面積58.5%，雖擁有豐富之森林資源，但森林面積之20%人工林約42萬ha，因未施行中後期撫育作業與其生育地不適應關係，導致林分生長競爭與森林劣化。人工林劣化監測為目前重要工作，本研究以多光譜MODIS衛星遙測影像，利用林木葉片葉綠素含量及水分含量高低光譜特性推導森林健康指標，包括葉片葉綠素含量之常態化差異植生指標（Normalized Difference Vegetation Index, NDVI）及重新常態化差異植生指標（Renormalized Difference Vegetation Index, RDVI），與水分含量有關之常態化差異水分指標（Normalized Difference Water Index, NDWI）及總體植生水分指標（Global Vegetation Moisture Index, GVMI），比較不同季節影像對於人工林林分健康程度監測的穩定性及其可用性。結果顯示四種以遙測影像所建立之森林健康指標，可以有效地鑑別森林健康狀態，而以冬季影像對於檢測森林健康狀態之差異性最為敏感。

關鍵字

森林健康 ； MODIS衛星影像 ； 植生指標 ； 葉綠素 ； 水份含量

並列摘要

Although there are approximately 58.5% forest cover and abundant forest resource in Taiwan, but which has 20% artificial forest about 420,000 ha without execute the tending or non-adaptive site that had occurred growth competition and become forest degradation. Currently how to detect forest degradation is an important issue for artificial forest. This research use the relational spectrum of chlorophyll content and canopy water content of MODIS satellite data to assess the forest health index that included Normalized Difference Vegetation Index (NDVI), Renormalized Difference Vegetation Index (RDVI), Normalized Difference Water Index (NDWI) and Global Vegetation Moisture Index (GVMI) to monitor the health condition for large area of artificial forest. Results show all of indices are more sensitive variation in winter season that indicated the winter's satellite imagery could be applied effectively to detect variations in forest health condition.

並列關鍵字

Forest health ； MODIS-Terra image data ； Vegetation index ； Chlorophyll ； Moisture