Detecting long-term global forest change using continuous fields of tree-cover maps from 8-km advanced very high resolution radiometer (AVHRR) data for the years 1982-99
Detecting long-term global forest change using continuous fields of tree-cover maps from 8-km advanced very high resolution radiometer (AVHRR) data for the years 1982-99
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DOI：
10.1007/s10021-004-0243-3
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发表时间：
2004-11-01
期刊：
影响因子：
3.7
通讯作者：
DeFries, RS
中科院分区：
文献类型：
--
作者：
Hansen, MC;DeFries, RS
本文描述了全球森林覆盖的变化，从1982年至1999年的基础上，8公里的探路者高级甚高分辨率辐射计（AVHRR）数据集。该程序涉及到使用回归树预测百分之树覆盖率为1982年至1999年。训练数据是从高分辨率图像中生成的，并与从年度高级甚高分辨率辐射计时间序列中得出的物候指标一起使用。使用18年的估计树木覆盖，并根据阈值的方法，我们确定了树木覆盖发生变化的位置。然后将变化地点与一组高分辨率森林砍伐分析进行比较，以产生森林砍伐和再生的面积估计。从1980年代到1990年代，全球树木覆盖率下降，与联合国粮食及农业组织（粮农组织）报告的全球森林覆盖率增加形成对比。拉丁美洲和热带亚洲是两个主要的毁林区域。巴拉圭的森林砍伐率在时间序列中最高，而印度尼西亚在1980年代至1990年代期间的森林砍伐率增幅最大。我们还建议，百分之树木覆盖率地图可用于标准化国家森林统计，作为一种客观的手段，确定热点变化，并促进生态系统监测。
This paper describes global changes in forest cover from 1982 to 1999 based on the 8-km Pathfinder Advanced Very High Resolution Radiometer (AVHRR) data set. The procedure involves the use of a regression tree in predicting percent tree cover for the years 1982-99. Training data are created from high-resolution imagery and used with phenological metrics derived from the annual AVHRR time series. Using the 18 years of estimated tree cover, and based on a thresholding approach, we identified locations where change in tree cover has occurred. The change sites were then compared to a set of high-resolution deforestation analyses to yield area estimates of deforestation and regrowth. Percent tree cover was found to have decreased globally, from the 1980s to 1990s, in contrast to United Nations Food and Agriculture Organization (FAO) reports of a global increase in forest cover. Latin America and tropical Asia are the two dominant deforestation regions. Paraguay shows the highest rate of forest clearing over the time series, while Indonesia had the greatest increase in deforestation from the 1980s to 1990s. We also suggest that the percent tree-cover maps can be used in standardizing national forest statistics, as an objective means of identifying hot spots of change, and for facilitating ecosystem monitoring.