A typical pattern of vegetation conditions in southern Africa during El Nino years detected from AVHRR data using three-channel numerical index.

The 1997-98 El Nino is one of the strongest events of the last 50 years. Its absolute magnitude, areal extent, and rapid development have raised a serious concern among decision makers because of its possible impact on global ecosystems. In this study, El Nino consequences for land ecosystem were examined using the new AVHRR-based three-channel index (VT), widely used for monitoring drought around the world. The VT index was used to identify a typical pattern of vegetation conditions in southern Africa during the recent El Nino years. Features and trends of the 1997-98 El Nino including its intensity, extent, and impact on vegetation are also discussed.