Regional analysis of crop and natural vegetation in West Africa based on NDVI metrics

In West Africa, rainfall variability dynamics are often considered as the major driver of vegetation production. Land use shifts have also to be taken into account when analyzing changes in vegetation production. To study how land use changes may impact vegetation response along a climatic gradient, we used three MODIS NDVI metrics time series (2000-2012) and a land cover map from MODIS Land Cover product. We performed a trend analysis and analyzed temporal profiles of the three metrics according to three climatic zones (Sahelian, Sudanian and Guinean zones). Our results indicate differences in NDVI values of Croplands and Natural Vegetation and that these differences are in connection with climatic zones. In the Sahelian zone Croplands tend to have higher values than Natural vegetation, whereas the opposite is observed for the Sudanian and Guinean zones. These results could help improve the interpretation of vegetation trends in a context of climate and land management shifts.