Automated Hazard Assessment Techniques Using Satellite Images Following the 2008 Sichuan China Earthquake

Abstract

ABSTRACT Rapid seismic hazard assessment is crucial for accurate damage estimation right after earthquakes. New technologies provide faster damage detection compared to the traditional, manual assessments. One of the new technologies includes using satellite images. Pre- and post-earthquake satellite images can be used to identify damage patterns. One of the recent disastrous earthquakes occurred in Sichuan (Mw = 7.9) on May 12, 2008. Records show that 5 million buildings have collapsed, and more than 21 million buildings were damaged. This article presents an approach for earthquake hazard assessment using a change detection method applied to pre- and post-earthquake satellite imagery of Sichuan. The damage inspection for the identified areas was carried out performing image analysis of the pre- and post-event satellite images. In this study, a novel automated image analysis technique was developed to assess the impact of the earthquake on the flooding of the area's rivers as well as the tectonic movement of mountains. The technique was used to quantify the flooding and movement of mountains in Sichuan right after the earthquake. The proposed methodology utilizes satellite images and may potentially be used as a rapid procedure to quantify damage soon after an earthquake.