基于EOS/MODIS 数据的NDVI 与 EVI 比较研究

作为NOAA/AVHRR 归一化植被指数(NDVI) 的延续和发展, EOS/MODIS 归一化植被指 数(NDVI) 和增强植被指数( EVI) 在许多领域得到广泛应用。应用数理统计和地统计学方法对二 者进行的对比研究表明: NDVI 在植被生长旺盛期容易达到饱和, 而EVI 则能克服这一现象, 比 较真实地反映植被的生长变化过程; 相同空间分辨率下, EVI 取值范围、标准差与变异系数均高 于NDVI, NDVI 数据比较均一, 其空间相关性高于EVI, EVI 更能反映研究区域内植被空间差异。 关键词:MODIS; 归一化植被指数(NDVI) ; 增强植被指数( EVI) ; 对比

Comparison of NDVI and EVI based on EOS/MODIS data

As the continuation and development of NOAA/AVHRR NDVI,the normalized difference vegetation index(NDVI) and enhanced vegetation index(EVI) of MODIS have been comprehensively used in many fields.In order to investigate the difference between NDVI and EVI derived from MODIS,comparative study of these two vegetation indices was conducted by statistics and geo-statistic methods(semi-variance function).By the comparison of the two kinds of vegetation index distribution maps in different period,it is demonstrated that EVI improve the sensitivity for well-vegetated areas where NDVI is saturated when plants grow well,which will be helpful in monitoring plants growth status.At same resolution,i.e.250m,500m and 1000m,by means of the geo-statistics,the results show that range,variance and variation coefficient of EVI is higher than that of NDVI,the value of NDVI is even,and its spatial relativity is higher than that of EVI,which all show that EVI is more sensitive to the spatial heterogeneity of plants in research area.