2004 Volume 17 Issue 5 Pages 459-467
Global vegetation and land cover changes from 1982 to 2000 are analyzed by using PAL (Pathfinder Advanced Very High Resolution Radiometer Land data sets). Annual integrated NDVI (ΣNDVI), annual maximum NDVI (NDVImax), standard deviation of ΣNDVI (NDVIstd), annual maximum surface temperature (Tmax), and annual trajectory in Ts (surface temperature)-NDVI space (TRJ) are adopted as parameters that reflect surface conditions, and examined their linear trends from 1982 to 2000. As a result, non-random spatial patterns are obtained. Part of which can be explained by climate-driven trend as stated in previous papers, however, obvious human-driven trend can be detected. Causal analyses on vegetation and land cover changes requires the consideration of both climate-driven causes and human-driven causes, and the viewpoints of different spatial scales are necessary to understand environmental changes. The signals concerning changes in heat budget by agricultural practices in relatively large spatial extent are important findings that suggest the effect of human activities to local climate.
