The spatial and temporal responses of natural landscape ecosystems in the Northeast region of Brazil (NEB) to changes in rainfall conditions over the last two decades of the 20th century have not been fully examined. The NEB ecosystems are highly dynamic landscape responding to weather conditions, of which rainfall is the most important variable. The research described in this book was conducted to test whether or not the impact of rainfall fluctuations on the vegetation dynamics can be spatially and temporally differentiated within the NEB ecosystems. The spatial and temporal consistency of the response of monthly normalized difference vegetation index (NDVI) derived from Advanced Very High Resolution Radiometer (AVHRR) data records to monthly rain gauge data records was assessed. The results suggest that vegetation responses over the NEB ecosystems to changing rainfall conditions, as measured by changes in NDVI to rainfall fluctuations, may have a potential for predicting the impact of rainfall conditions on the NEB landscape dynamics.