Cornerstones and epilogue of the GRFM Africa project: a gallery of regional scale vegetation maps

The Global Rain Forest Mapping project (GRFM) is an initiative started by the National Agency for Space Development of Japan (NASDA) in 1996 with the main goal of creating a wall to wall radar map of the tropical belt with homogeneous and consistent characteristics. GRFM Africa-the part of the project related to tropical Africa-has evolved through several years to the stage where significant thematic products have been generated. It is maintained that these products bear relevance to global change studies and to the sustainable management of local resources in the tropics. The objective of this paper is to lend support to this proposition by illustrating through a few examples the results achieved so far. In particular two land cover maps are presented covering respectively the Central Congo basin, and the Gabon country. Validation of these large-scale high-resolution products poses a challenging problem. The method adopted in GRFM Africa is outlined. It is based on comparison with independent thematic information with known error budget, derived from a combination of optical remote sensing observations, national forestry maps and ground surveys.