Real-time vegetation monitoring with NOAA-AVHRR in southern Africa for wildlife management and food security assessment

The monitoring of vegetation in Southern Africa with satellite data has become increasingly important over the past decade because it is linked to variation in agricultural production and climate change with implications for wildlife management and tourism. This study shows how maps of vegetation status were produced in near real time from NOAA images acquired from the local receiving stations in Etosha National Park, Namibia and in Zambia. Map products based on the NDVI were put into historical context and stratified to remove effects of the main vegetation types in order to assess vegetation status. The historical data were extracted from the FAO ARTEMIS NDVI archive and processed to obtain a statistical distribution of the NDVI for each 10-day period of the year and vegetation type by applying techniques commonly used in hydrology for the prediction of extreme events. The quintile probability ranges were used to define five classes of a Vegetation Productivity Indicator (VPI). LAC NDVI images obtained in real-time from the receiving station were processed to derive a VPI map for each 10-day period. In Etosha National Park and in Zambia, the VPI was strongly related to the rainfall and the VPI maps provided improved information on the spatial variations. The weighted average VPI for the main agricultural region of Zambia was significantly correlated with maize production.