| Abstract |
Deforestation, caused both by clearing of fields and by excessive wood harvesting, has been reported to be widespread in the north-central communal areas in Namibia, yet little quantitative information is available on the severity of this form of land degradation. The two biodiversity observatories Ogongo and Omano go Ndjamba are located in the Omusati Region, taking advantage of the unique situation at the Ogongo Campus of the University of Namibia, where the vegetation is protected in a near-pristine condition. The Omano go Ndjamba observatory is situated about 5 km to the west of this, within the typical communal subsistence agriculture land use system found in the region. High-resolution aerial surveys have been undertaken during March 2017 at both observatories. From the resulting images, normalised excessive green index maps (exG2) have been calculated and individual woody plants were delineated. The woody cover and height of plants could be determined at both observatories using the exG2 index and a DSM generated from the aerial images. Direct deforestation (i.e., the clearing of natural vegetation) occurred on 2.5% of the total area in the Ogongo observatory, and on 13.1% at the Omano go Ndjamba observatory. Forest degradation through wood harvesting, however, is of a far greater concern: whereas the woody cover at Ogongo is on average 43.3%, this has been reduced to between 17.7% and 7.5% (depending on land use) at Omano go Ndjamba. This trend is also associated with a reduction in plant height, with tall shrubs and trees being replaced by short coppicing shrubs at Omano go Ndjamba. The impacts of this forest degradation are a loss of provisioning ecosystem services and the potential for total desertification of the area. The use of UAV (drone) aerial images proved to be very suitable for a quick assessment of degradation states, provided a suitable baseline is available. |
? |
| Citation |
Strohbach, B.J. (2018) Determining the degree of deforestation in the Omusati Region, northern Namibia, with the aid of drone imagery In: Climate change and adaptive land management in southern Africa – assessments, changes, challenges, and solutions (ed. by Revermann, R., Krewenka, K.M., Schmiedel, U., Olwoch, J.M., Helmschrot, J. & Jürgens, N.), pp. 370-377, Biodiversity & Ecology, 6, Klaus Hess Publishers, Göttingen & Windhoek. doi:10.7809/b-e.00348 |
? |
