Abstract:

The temporal and spatial variation characteristics of NDVI and EVI along the Yangtze River in Anhui province are compared by using multitemporal TERRA/MODIS remote sensing images,and the spatial resolution and the atmospheric correction influences on NDVI and EVI are also analyzed in this paper.The results show that the vegetation coverage conditions reflected by MODIS / NDVI and MODIS / EVI are basically the same. The spatial distribution in May shows more obvious differences than that in August,and in vigorous growth period,EVI can reflect the vegetation coverage conditions better than NDVI.In the same spatial resolution (250 m,500 m,1000 m),EVI can reflect the spatial differences of the vegetation coverage much better than NDVI.With the reducing of the spatial resolution,the differences of the vegetation coverage reflected by the two kinds of indexes also decrease.Atmospheric correction has different influences on NDVI and EVI.The values of NDVI are lower than the EVI values before the atmospheric correction,while after the atmospheric correction,the values of NDVI are generally higher than the EVI values.The atmospheric correction has less effect on the NDVI but more significant effect on EVI