ABSTRACT
In 1990, the European Commission (EC) issued a green paper on urban environment (Green Paper on the Urban Environment, 1990) addressing the main problems in urban areas and the need to monitor their environmental conditions. This document covered the environmental effects of urban growth not only in Europe, but also in other parts of the world. For environmental management and sustainable development, accurate and comprehensive spatial data are critical. The lack of appropriate data is a major hindrance for policy makers and the scientific community. In the light
of sustainable development, comparable information is essential, which requires a collective effort from various players.
