Combining AVHRR-NDVI and landuse data to describe temporal and spatial dynamics of vegetation

A combination of high temporal resolution Advanced Very High Resolution Rad iometer (AVHRR) data (1000 m), and high spatial resolution landuse/landcove r data (200 m) from the Oklahoma Natural Resources Conservation Service (NR CS) were used to investigate the temporal and spatial dynamics of Oklahoma vegetation. The dates and relative magnitudes for onset-of-greenness, peak, and senescence were identified for four major landcover types using a 7-ye ar average of bi-weekly maximum AVHRR Normalized Difference Vegetation Inde x (NDVI) data. While onset and senescence dates were similar for all landco ver classes, the major differences occurred in the magnitudes and time peri ods for the peak NDVI values, It was shown that the hi-weekly maximum NDVI data were capable of discriminating rangelands with different canopy densit ies of tree and shrub species consistently across years. (C) 2000 Elsevier Science B.V. All rights reserved.