The science community is in no doubt that extreme weather events like hurricanes, floods and windstorms are increasing in intensity and frequency. Emergency management agencies are therefore turning to radar satellite imagery to obtain useful geographic information rapidly.
Floods in Andalusia - Meteosat satellite image, 27/02/2010
Spain drenched by torrential rains
During the winter of 2009-2010, rains are lashing the Iberian Peninsula.
In February 2010, torrential downpours persist for several weeks in Andalusia, normally a very dry region of the country.
The human and economic impacts are heightened when the Guadalquivir River bursts its banks, forcing the authorities to evacuate populations and to close motorways and Jerez airport.
Request from the Andalusian water agency
EGMASA, the Andalusian environment and water agency, is tasked with providing environmental protection support in emergency situations.
The agency was required to supply a map to the Junta de Andalucía during the emergency phase of the crisis.
To rapidly survey flooded areas, it requested radar data from Airbus Defence and Space in Barcelona.
TerraSAR-X Programmation form February 27th to March 8th
Emergency imaging of five areas
The TerraSAR-X satellite was immediately tasked to acquire imagery of 4 areas along the Guadalquivir—at Lora del Río, Seville, Cordoba and Andujar—and of another area further south at Jerez de la Frontera. The 1st images were delivered to the agency within 24 hours. Acquisitions were spread over 10 days, from 27 February to 8 March.
Automatic vectorisation of flood areas
Standing water has a characteristic spectral signature in radar images. Flood areas were extracted from the radar image by segmentation and then vectorised. The vector layer was checked and then draped over an optical satellite image. A 1:25 000 map was generated to highlight the impact of the floods.
Map of floods on February 27th 2010 in Lora del Rio
Delivery in 48 hours
Maps of the flood areas were delivered within 48 hours of image acquisition.
Thanks to the radar sensor technology and automated data production process, accurate wide-area geographic information was supplied rapidly in the heat of the crisis.
The radar sensor “sees through” clouds to provide a picture of the situation on the ground.