最近18年来中国植被覆盖的动态变化

DYNAMIC VEGETATION COVER CHANGE OVER THE LAST 18 YEARS IN CHINA

基于遥感和地理信息系统技术，利用ＮＯＡＡ－ＡＶＨＲＲ数据对我国最近１８年（１９８２～１９９９）来的植被覆盖的动态变化进行了分析。结果表明：我国植被覆盖的动态变化受气候波动的影响十分显著，并且这种变化的区域性差异明显。１８年来，ＮＤＶＩ减小的地区主要分布在西北地区和青藏高原，而ＮＤＶＩ增加的地区主要发生在东部地区；２０世纪８０年代和９０年代的ＮＤＶＩ变化趋势之间存在较大差异；９０年代ＮＤＶＩ减小的区域明显地比８０年代增加，特别是西北干旱地区ＮＤＶＩ的下降趋势明显。我国珠江三角洲和长江三角洲地区是１８年来植被覆盖下降趋势最明显的地区，表明快速城市化的影响。

Dynamic changes in Chinese terrestrial vegetation over the last 18 years from 1982 to 1999 and their spatial patterns were explored, using NDVI (normalized difference vegetation index) data derived from remote sensing imagery (NOAA/AVHRR), along with the information of vegetation distribution and climatic records. As a result, the dynamic vegetation cover change was closely coupled with climatic fluctuation, and showed a remarkable regional difference. In the past 18 years, regions with significant decline in NDVI appeared in Northwest China and Tibetan Plateau whilest a marked increase occurred in eastern regions of the country. The trends in interannual NDVI change displayed a large discrepancy between 1980's and 1990's; areas with decline in NDVI in 1990's was considerably larger than in 1980's, especially for northwest arid region. Due to rapid urbanization, Zhujiang River delta and Changjiang River delta showed a sharp drop in NDVI during the past 18 years.