SIR-C/X space shuttle images contribution in assessment of flood risk. The case of Athens basin

This study describes the investigation conducted for flood risk assessment in urban areas using SIR-C data. The Athens basin is a densely populated area with approximately four million inhabitants, affected very often by destructive flash-floods. These flood phenomena occur mainly at the margins of the urban area very close to the surrounding mountains. The SIR-C image, acquired on October 2nd, 1994, has been processed for speckle reduction and additionally a non-linear stretching has been applied. After the first observations at every single image, a false colour composite image was created using L-band HV, C-band HH, and L-band HH as R,G,B. The captured information concerns morphology (topography, slopes, gullies), land use and land cover, drainage characteristics and building shell extension, density and block orientation.