6533b839fe1ef96bd12a5a0e

RESEARCH PRODUCT

Compared regimes of NDVI and rainfall in semi‐arid regions of Africa

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description

Bi‐monthly normalized difference vegetation index (NDVI) at an 8 km spatial resolution from the advanced very high resolution radiometers (AVHRR) was used from 1981 to 1995 to analyse the vegetation response to rainfall supply in semi‐arid regions of Africa. Within the 200–600 mm annual rainfall belt, for which the apparent NDVI response to rainfall was the strongest, three regions were selected which exhibited different patterns in their NDVI regimes and/or relationships with rainfall. The regions, located in western, southern and eastern Africa, were split into coherent sub‐regions in terms of mean regime of photosynthetic activity through a cluster analysis. Overall, intra‐regional differences were found to be of relatively minor importance compared with inter‐regional differences. The mean annual rain‐use efficiency (RUEa) was the highest in southern Africa, followed by that in eastern Africa, and it was the lowest in western Africa. In eastern Africa, a distinctive feature was found which consisted o...