ANALYZING TIME SERIES OF VEGETATION INDEX AND LAND COVER FOR VEGETATION CHANGE DETECTION OVER CONTINENTAL US

摘要

Global climate change has attracted increasing attentions in recent years as a challenge facing human life. Accurately mapping, quantifying and monitoring changes in the physical characteristics of vegetation cover is a key element in the study of global climate change.rnThe normalized difference vegetation index (NDVI) has been used extensively in ecosystem and climate monitoring. This paper examined vegetation change over the last 27 years (1981-2007) over Continental US. Using history of the values of the normalized difference vegetation index (NDVI) which is extracted from satellite sensor data acquired by the National Oceanic & Atmospheric Administration - Advanced Very High Resolution Radiometer (NOAA-AVHRR), long time series of satellite-derived vegetation index has been studied showing the increasing trend of vegetation index over Continental US from 1981 to 2007. The results demonstrated that the change of NDVI shows an increasing trend which might be induced by the global warming. The comparison of the land cover data in 1981 and 2001 validated the uptrend of NDVI.