摘要
为了了解西北地区MODIS/NDVI和MODS/EVI 2种植被指数的特点,利用2003年植被生长期TERRA/MODIS资料和西北地区植被类型数据,分析了西北地区MODIS/NDVI和MODIS/EVI空间分布特征和不同类型植被随时间变化特征,比较了大气订正对NDVI和EVI的影响。结果表明:NDVI和EVI空间分布格局一致,与降水空间分布形式比较一致。NDVI与EVI值的差异随着植被覆盖度的增加而增大。不同类型植被NDVI和EVI变化特征一致。大气对NDVI和EVI的影响较大,大气订正前许多地区NDVI值小于EVI值。大气订正使NDVI增大,EVI减小,大气订正后NDVI值普遍大于EVI值。通过对大气气溶胶粒子较多地区的NDVI和EVI值的对比分析,EVI具有较好的抗大气气溶胶的作用。
Using TERRA/MODIS data in some typical vegetation regions during plant growth period in 2003 and vegetation type data, the spatial and temporal characteristics of MODIS/NDVI and MODIS/EVI in Northwest China and the influences of atmosphere correction on the two vegetation indexes were analyzed in this paper for comparing the differences between NDVI and EVI. The results show that distributions of NDVI and EVI are consistent in space and nearly the same as that of precipitation. The difference between NDVI and EVI is larger as vegetation coverage increases. In addition, the influence of atmosphere on NDVI and EVI was obvious, and atmosphere correction made NDVI values increase and EVI values reduce; the values of NDVI are smaller than those of EVI before atmosphere correction; while after the correction, values of NDVI are larger than those of EVI in most regions. By comparing NDVI and EVI in those regions containing more aerosols, we found that EVI had a good performance in removing the influence of aerosols.
出处
《干旱气象》
2007年第1期38-43,共6页
Journal of Arid Meteorology
基金
国家自然基金项目(40375011)资助
