Disaster mapping from medium spatial resolution alos palsar images

All-day and all-weather Synthetic Aperture Radar (SAR) can measure both intensity and phase of the reflected signal. The backscattering coefficients measured by SAR reflect the backscatter characteristics of surface targets. Changes happened to a target´s surface roughness, geometric and structural characteristics will result in the change of its backscattering intensity recorded in SAR image. The 2008 Wenchuan earthquake, China have caused widely distributed geological disasters, such as landslides, mudfloods and barrier lakes, which resulted in the difference between pre- and post-earthquake SAR images. Comparison between the pre- and post-earthquake SAR intensity images will reveal the damage information. In this study, PALSAR Level 1.0 data acquired for the Wenchuan earthquake were used to analyze the geological disasters. Results show that medium spatial resolution SAR data, such as 10 m resolution ALOS PALSAR data, especially when both pre- and post-earthquake images are available, are useful in revealing the distribution of landslides and barrier lakes.