22 March 2006: A satellite-based rapid mapping service developed in eastern France is now ready and on call 24 hours a day, seven days a week. This service has been designed to manage floods, one of the world’s most widespread categories of natural disaster. Apart from being applied to risk assessment and prevention efforts, the ESA-backed Flood Plain Monitoring Service aims to deliver map products to end users within six hours during times of crisis, giving emergency responders the ability to track the full extent of floods as they occur.
Developed over three years through the ESA Earth Observation Market Development (EOMD) programme, the service was consolidated with France’s Eastern Defence Zone (EDZ), which is made up of 18 departments with a total area of 105 000 sq. km and a population of 8.3 million people. It also includes four major hydrological basins potentially vulnerable to flooding. The service provider is Strasbourg–based rapid mapping specialist firm SERTIT, with the EDZ Prefecture as partner end-user. The service is based on two types of satellite data. High-resolution imagery from optical satellites is combined with satellite radar imagery, which can be acquired even at night or through heavy cloud or rainfall. The large amount of detail found in optical images is used in advance to create reference land cover maps that can be combined when needed with radar images that are highly sensitive to waterlogged surfaces. These images can also be utilised in conjunction with digital elevation models (DEMs) derived from radar data to help model, which areas are most at risk.