Building Damage Assessment with VHR Images and Comparative Analysis for Yushu Earthquake, China

In the aftermath of a disaster, one urgent need is to estimate the degree of structural damage to physical infrastructure with adequate reliability and rapidity. The new generation of very high-resolution imagery (VHR, with a spatial resolution of 1 m or less), if acquired after an earthquake, can be used to assess structural damage at the building level. This paper presents the experience of post-earthquake building damage assessment for the Yushu earthquake using VHR imagery by three organizations: the Center for Earth Observation and Digital Earth, Chinese Academy of Sciences (CEODE), the German Aerospace Center (DLR) and the Joint Research Center, European Commission (JRC). The data sources and methodologies employed for building damage evaluation are presented. To assess the reliability of these sources and methodologies, damage assessment maps produced are compared. The intercomparision results indicate that damage assessment maps based on satellite VHR data are capable of capturing the damage distribution. However, these maps are not suitable for providing accurate information on the damage intensity as the results tend to be underestimated in areas where the damage is moderate and overestimated in areas with