Digital Processing and information extraction of multi type and mukti temporal remote sensing images for geological hazard in the Yangtze Three Gorges Project Region, China

International audienceIn this paper, under the RS, GIS and GPS technology, data fusion and orthophotomaps of multi-temporal Landsat TM, SPOT, ERS SAR and RADARSAT images are made. Furthermore a lot of information on geology and structural deformation is extracted. An orthophotomap is a new type of map accurately corrected for geometry and a composite one with a simplified topographic map. In this study, the authors conduct the data fusion of Landsat TM, SPOT and ERS SAR images. Then, utilizing RSthoMapper vl. 0 software explored by themselves, they make three kinds of orthophotomaps, that is 1 : 250 000 map of Kaixian, 1 : 100 000 map of Baishahe and 1 : 50 000 map of Yunyang respectively. The last one is an orthophotomap of fusion image of TM453 and SPOT panchromatic band with 10 m ground resolution, and DEM used in the rectification comes from SPOT stereopairs. Applying the 1 : 250 000 orthophotomap of Kaixian and the theory and method of phase-separation analysis of remote sensing information field, geological and structural features are systematically interpreted and the linear and circular structures are quantitatively analyzed. With a synthesizing analysis of the combined folds, faults and related major joint systems, four periods of structural deformation and the resulted deformation fields are determined. As a result, four tectonic stress fields produced successively during the Yanshanian to Himalayan period are recovered. Through the ARSIS fusion of the Landsat TM 4,5,3 images and SPOT P images, lots of best image results with a high spatial resolution of 10 m and affluent colors are obtained. Many 3-D viewing maps of remote sensing images of the landform relief with a high resolution and projected from different directions are established. With these maps, quantitative analysis as drawing a section of landform and detecting DEM of some objects can be done directly and rapidly