Development of a global land cover characteristics database and IGBP DISCover from 1 km AVHRR data

produced a 1 km resolution global land cover characteristics database for use in a wide range of continental- to global-scale environmental studies. This database provides a unique view of the broad patterns of the biogeographical and ecoclimatic diversity of the global land surface, and presents a detailed interpretation of the extent of human development. The project was carried out as an International Geosphere–Biosphere Programme, Data and Information Systems (IGBP-DIS) initiative. The IGBP DISCover global land cover product is an integral component of the global land cover database. DISCover includes 17 general land cover classes de � ned to meet the needs of IGBP core science projects. A formal accuracy assessment of the DISCover data layer will be completed in 1998. The 1 km global land cover database was developed through a continent-bycontinent unsupervised classi � cation of 1 km monthly Advanced Very High Resolution Radiometer (AVHRR) Normalized Di � erence Vegetation Index (NDVI) composites covering 1992–1993. Extensive post-classi�cation strati � cation was necessary to resolve spectral/temporal confusion between disparate land