A vegetation map of Central Africa derived from satellite imagery

Abstract

Aim: This paper presents the Joint Research Centre's TREES Project satellite derived Vegetation Map of Central Africa, at 1:5,000,000 scale, with a detailed description of the vegetation classes and their distribution. The information content of the map is compared with other conventional and satellite derived maps of the region for validation and evaluation purposes. Location: The map focuses on the Guineo-Congolian ecological domain and covers the following countries: Cameroon, Central African Republic, Republic of Congo, Equatorial Guinea, Gabon and the Democratic Republic of Congo. Methods: Using coarse resolution satellite imagery a map of vegetation cover has been produced based upon the spectral response of the vegetation cover. Digital image processing and geographical information systems techniques were employed, together with local knowledge, high resolution imagery and expert consultation, to compile a cartographic map product. Results: The TREES Vegetation Map of Central Africa has been shown to be strongly correlated with the FAO Forest Resources Assessment for 1990. Comparison with other map sources indicates that the map contains greater spatial detail and is more consistent than conventionally compiled maps. The conventional maps however, contain more thematic information content relating to vegetation type. Main conclusions: The map improves our state of knowledge of the vegetation cover of Central Africa and presents the most consistent and spatially detailed view yet published at this scale. Thematic information content on forest type is limited but should be improved in the near future with the inclusion of data from new satellite sensors. This first version of the map and future planned updates should provide an important input for regional stratification and planning purposes for forest resources, biodiversity and climate studies.