Forest map of southern Africa with the aid of LANDSAT imagery

Abstract

Even after 300 years of indigenous forest protection as well as 100 years of plantation forestry, no forestry map of South Africa was available. The development and availability of LANDSAT images in the early 1970s opened up possibilities to use satellite data. A project was initiated in 1981 to compile a forestry map of southern Africa (Republic of South-Africa, Swaziland, Lesotho, Ciskei, Venda, Transkei and Bophuthatswana). A portfolio of 31 maps on a scale of 1:250 000 has now been produced. Three examples of these form part of this report. A combination of LANDSAT and field data was used to bring about this set of maps. A number of teething problems were experienced, e.g. mountain shadow; distinction between pine and wattle; no tree canopy before about 10 years of plantation growth. In this report the procedure is discussed in detail. Problems are stated and solutions offered. Both sophisticated computer classification and qualitative approaches were used. The experience related in this report will be of considerable benefit to many other researchers and planners contemplating the inclusion of satellite data in their particular application fields