Limitations of crowdsourcing using the EMS-98 scale in remote disaster sensing

The combination of crowdsourcing and high-resolution aerial and satellite imagery have recently been explored in applications of post-disaster damage assessment and analytics. The large scale and distributed nature of these tasks produce overwhelming amounts of information that can be used to quickly assess post-disaster damage. While crowdsourcing provides fast, scalable analysis of a disaster area, the accuracy or usefulness of the data collected is not well understood. This paper investigates the variability and limitations in user assessment as observed by a standard damage assessment metric EMS-98, for each of the five damage categories. A case study is provided through the crowdsourced damage assessment of a region along the eastern shore of Japan that was effected by the 2011 earthquake and tsunami. High-resolution satellite imagery was captured after the event and was used to provide the images needed for damage assessment.