鍏抽敭璇�: 鍖哄煙妞嶈鎸囨暟 , AVHRR璧勬枡 , 妞嶇墿鐢熼暱鍛ㄦ湡

Abstract: In this paper mean values of normalized difference vegetation index(NDVI) and their standard deviations in 60 counties or cities of the eastern Gansu province using the NOAA satellite AVHRR data selected the clear days during 1991锝�1992 have been calculated.Their temporal profiles and histograms of each county are drawn.Three types of county with major crop,grassland and forest mixed with grassland have been selected and comparatively analysed.The space temporal evolution of vegetation index in county destrict level related to the crop and pasture stage is studied.The status of the winter wheat growth cycle during 1991锝�1992 under serious drought condition is analyzed as a focal point.The results provide the basis of optimum phase and parameters for monitoring drought,crop yield estimation and land use classification.

Key words: Regional vegetation index , AVHRR data , Plant growth cycle