Assessment of Land Degradation, Its Possible Causes and Threat to Food Security in Sub-Saharan Africa

This chapter aims to use the long-term Normalized Difference Vegetation Index data as a proxy to map the spatial distribution of change in net primary productivity (NPP) for Sub-Saharan Africa. The anthropogenic causes of land degradation are related to an ever-increasing demand for food, fodder, fiber, and fuel, as well as shelter and other infrastructure. Assessing soil degradation at a global, continental, or regional scale is hampered by a shortage of data for long-term quantitative comparisons. Monitoring land degradation using remote sensing of NPP is an easier task, especially since satellite imagery has become publicly available. Some scientists even consider Rain Use Efficiency (RUE) a valid indicator for soil degradation, because a decline in RUE appeared to correspond with modeled soil erosion driven by the same rainfall data. Immediate adaptation strategies are needed in areas characterized by favorable soil and terrain where population pressure is high and degradation is in full progress.