The satellite-derived normalised difference vegetation index (NDVI) offers new opportunities to assess the impact of year-to-year climate fluctuations. In this study the NDVI is mapped over southern Africa for the period 1981-1994. Sharp upward and downward trends follow the cycle of summer flood and drought. January to March NDVI values are correlated at +0.82 with harvested maize yield for the North West Province of central South Africa. Departures of late summer NDVI from the historical mean illustrates the distribution and intensity of the influence of the Southern Oscillation, in alternating seasons of vegetative growth and depletion. The first principal component of the NDVI field time series contains a broad signal covering all of Africa south of 15 degrees S, and appears related to the low frequency component of the global El Nino phenomenon.
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