Do we need a global human settlement analysis system based on satellite imagery?

Urbanization figures that document the rapid urbanization of this century are derived from census data and available from population figures aggregated at the administrative level. These invaluable figures for reporting purposes are unsuited for the operational physical analysis of the global built environment. The rigorous quantification of the built up environment is required for city and regional planning, national comparative built up analysis within cities and rural areas, global built up assessment for climate change models and for environmental change adaptation measures especially in coastal areas, as well as proxy to exposure in disaster early warnings systems and disaster loss models. The paper briefly analyses the potential alternative sources for physical built up and identifies the advantages of aerial and High Resolution satellite imagery for this task. The paper provides an analysis of the required data needed to monitor urbanization. This paper introduces the GHSL used to process imager for the analysis of the built environment. It then focuses one processing products that derives human settlement information from the processing of Very High Resolution imagery. The paper shows with an example, the potential of such systems and shows the strategies to measure the extent of built up areas and also support the criteria to validate a future global human settlement layer.