Mapping and monitoring woody vegetation in Namibia
Namibia has experienced extensive bush encroachment which has negative economic impacts on livestock production and water availability. However, the bush encroachment also provides positive opportunities for biomass-based energy production. Current de-bushing efforts are carried out without reliable maps of woody vegetation to aid planning and policy. The objective of our research project was to develop a system which can map and monitor woody vegetation cover and biomass at national scale. The system uses large tracks of high resolution airborne LiDAR data as training for machine learning models which then predicts and maps woody cover using Synthetic Aperture Radar (SAR) data.
Woody cover change maps were calculated by subtracting an earlier woody cover map from a later map (e.g. 2015-2010). Large sites of debushing were very effectively detected. Increases in cover appeared to have taken place in historically debushed areas. This operational woody vegetation monitoring system is also being applied in South Africa. The project is funded by Southern African Science Service Centre for Climate Change and Adaptive Land Management (SASSCAL) of the German Federal Ministry for Education and Research.