Damage information derived from multi-sensor data of the Wenchuan Earthquake of May 2008

Abstract

The Wenchuan Earthquake of magnitude 8.0 struck Sichuan Province in south-west China on 12 May 2008. This paper presents an overview of the use of multi-source satellite images in investigating the influence of this earthquake around the epicentral area. The results show the capability of remote sensing technique for damage detection in quake-hit areas. Optical satellite images (FORMOSAT-2 and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)) provide useful information, although rain and cloud limit the availability of satellite data. However, the Synthetic Aperture Radar (SAR) sensor provides information in all weather conditions. Combined optical satellite and SAR data have been used to assess the damage of earthquakes, including landslides, barrier lakes and collapsed buildings. From the interferogram of two phased array type L-band SAR (PALSAR)/Advanced Land Observing Satellite (ALOS) images, more than 100 cm of ground displacement was found in Beichuan County, one of the worst-affected earthquake areas. These examples show the use of satellite images in post-disaster damage assessment and planning during the rescue operation soon after a major event such as the 12 May 2008 earthquake.