Land use and urban sustainability assessment: a 3D-GIS application to a case study in Gozo

Balancing urban growth and natural resource availability has been recognized as the main challenge of the 21st century from the strategic documents adopted by the recent World Summits. Agenda 21 advocates sustainable land use, as soil is a crucial natural resource to reduce urban vulnerability due e.g. to climate change, energy saving, and natural disasters. In this perspective, this paper aims at supporting local decision makers in identifying the portions and the buildings of an urban area most susceptible to transformation, in order to promote a sustainable land use according to physical and functional characteristics. The proposed methodology combines the 3D modeling of urban settlements and the adoption of the performance-based approach by the urban transformation government, in order to guarantee the satisfaction of the supply–demand ratio through a compatible balance between urban growth dynamics and the overall urban efficiency. The test area was Gozo island, where a significant urban transformation will occur as a consequence of the new Malta-Gozo tunnel construction.