Data entry, modeling and graphical output for the Uganda case study have been carried out with the ARC/INFO Geographic Information System on a PRIME minicomputer. Most of the basic datasets were digitized from the Atlas of Uganda (1964 and 1967 editions). More recent data for the whole country were not available; layers such as land use and forest reserves are out of date. However, the majority of data entered can be assumed unchanged (geology, terrain, soils), and some of the outdated layers were compared with more recent satellite imagery in order to map temporal changes. Derived datasets have been grouped into two classes: 1st and higher order. In 1st order derivations, only attribute information has been added or changed, for example the map of soil productivity. In higher order derivations, boundaries have been changed, and entirely new entities created.