The world population explosion is accompanied by rapid urbanisation causing urban sprawl. Since 2008, for the first time in the history of humanity, over half the population has been living in an urban environment. In 2050, it is estimated that around 70% of the world’s population will be city-dwellers. This urbanisation will weigh heavily on natural resources globally, with tensions over available land, habitats and biodiversity. Food demands should double, power consumption increase by 80% and water supply needs by 55 %... These huge challenges will only be met if efficient cities are planned, capable of synergy between consumption and production. In view of these challenges, it has become vital for numerous operational applications to monitor artificialisation, and to detect and characterise urban change. In such circumstances, remote sensing represents an extraordinary wealth of information.
Satellite images are a source of value-added information (in terms of spatial, temporal and spectral resolution) that needs to be fully exploited today so as to rise to these numerous challenges.