The ability of geographic information systems (GIS) to store, integrate, analyze, and display spatial attributes of socioeconomic and environmental data has meant that they are increasingly applied to environmental impact assessments (EIA). According to Antunes et al.(1996: 451) attempts to employ GIS in EIA have demonstrated that “GIS can have a wide application in all EIA stages, acting as an integrative framework for the whole process, from the generation, storage and display of the thematic information relative to the vulnerability/sensitivity of the affected resources, to impact prediction and finally for their evaluation for decision support.” However, despite this acknowledged potential, it is unclear if in practice much of the use of GIS by EIA practitioners is restricted to map production and report preparation. If it is the case that GIS are mainly used as sophisticated mapmaking tools, and the powerful capabilities of data modeling and analysis are disregarded, then GIS are not being used to their full capacity and surely less complex (and cheaper) systems could frequently be used instead.