基于EOF分析的三江源区植被覆盖变化时空分布特征

The vegetation distribution characteristics in the Three-River Headwaters Region in China based on EOF analysis

基于遥感图像1999—2010年SPOT-VEGETATION NDVI数据,利用经验正交函数(EOF)分析方法,研究了近12a来三江源区植被变化的时空分布特征。结果显示近12a来源区植被覆盖呈整体增加趋势:(1)第一特征向量(方差贡献率为45.62%)及对应时间系数表明源区植被覆盖逐渐增加,且增速加快;(2)第二特征向量(方差贡献率为9.77%)及对应时间系数表明东南部和中部植被变化情况以退化为主,而东北部和西南部植被变化情况以增加为主。

Based on SPOT VEGETATION NDVI data from 1999 to 2010, the temporal and spatial distribution characteristics of NDVI in the Three-River Headwaters Region were analyzed by means of the Empirical Orthogonal Function （EOF）. The results showed that （1） the vegetation NDVI of the Three-River Headwa- ters Region had a rising trend, and the first eigenvector（accounting for 45.62% of the total variance） and its temporal coefficients exhibited that the vegetation NDVI was improved with an increasing rate; that （2） the second eigenvector （accounting for 9.77% of the total variance） and its temporal coefficients displayed that the vegetation NDVI was reduced in southeastern and central area, and in contrast, it increased in northeastern and southwestern area.