ANALYSIS OF THE SPECTRE OF URBAN DENSITY FROM THE PERSPECTIVE OF COMPACTNESS OF FORMS A response to a new urban vulnerability

The concepts of density and urban morphology are today at the centre of debates on architecture and urban planning. The concept of density provides a solution to the issue of urban sprawl and, consequently, offers a way of rethinking sustainable urban and rural development. The densifi-cation of urban centres makes it possible to reduce a vulnerability related to the excessive use of suburban areas. However, densification is not a “turnkey ” solution. Numerous criteria relating to its use are poorly understood. As numerous contemporary experiences have demonstrated, urban densification exposes space systems to new, unknown forms of vulnerability. First, we will define the concept of vulnerability, specifically that of urban vulnerability, as well as related concepts, such as those of risk, hazard and challenges. Secondly, we will pinpoint forms of vulnerability inherent in the over-densification paradigm: this will involve determining the spe-cific hazards, challenges and risks of this space system. Thirdly, we will demonstrate how the concept of compactness makes it possible to review at the different urban levels the densification processes of territories and urban areas. Finally, we will propose a tool for the optimisation of compact urban morphologies for use in countering the related hazards and risks. 1