Very high spatial resolution images and flood risk

Abstract

The very high spatial resolution (VHSR) aerial or satellite images contribute to environmental studies providing the vision of human size features. To process these thin resolution images, the most efficient approaches are not based on automatic classification any more but on computer assisted photointerpration. This paper presents two applications, which illustrate the potential of these images in the case of flood risk. The first one is related to the vulnerability: the useful objects for management are first classified into 3 hierarchical levels, in order to better compare the interest of VHRS images with the existing geographical data bases and the intermediate resolution images. The second one deals with the characterization of the flood phenomenon through an original use of aerial photographs to obtain the water height for any flooded point. That constitutes a quantitative valorization under GIS of aerial photographs archives and soon, of VHSR satellite images.