Geographical Information Systems (GIS) have developed rapidly in recent years and now provide powerful tools for the capture, manipulation, integration, interrogation, modelling, analysis and visualisation of data - tools that are already used for policy support in a wide range of areas at almost all geographic and administrative levels. This holds especially for emergency preparedness and health risk reduction, which are all essentially spatial problems. To date, however, many initiatives have remained disconnected and uncoordinated, leading to less powerful, less compatible and less widely...