Analysing land cover changes in the Caprivi Strip, Namibia, using Landsat TM and Spot XS imagery

Abstract: The Caprivi area, situated in the north-eastern part of Namibia, Africa, has experienced a high population increase during the latest ten years. Studies have shown that the vegetation has been influenced as the woodlands, that provide the population with timber and charcoal, have been cut down. Also, the fires have increased in the area, as the people need to cultivate the land in a higher degree. Since the country is widespread, remote sensing is an alternative to field studies in order to survey the extent of vegetation changes. It was suggested by the NRSC (National Remote Sensing Centre) in Namibia, that a vegetation change method in the area was to be studied. The method should be swift and yet accurate. Using two different satellite scenes, one SPOT XS from 1992 and one Landsat TM from 1994, a method analysing signatures with a paired t-test was used. Three spectral band were examined, the green, the red and the near infrared, in each scene. Together with a signature separability test, the t-test showed if changes had occurred or not in each band and which signatures that were separable. Using literature studies, the result was analysed and interpreted. Both the vegetation change method and precipitation data from the area showed that the climatic conditions has become drier during the time period, as the green vegetation cover has decreased and become more senesced. The short time duration did not prove any substantial human influence on the tree cover.