Surfing the Wave: Using Social Media to Gather Usable Data on Flood Extents

Floods, and other natural disasters, present a challenge to local communities: during a major event, the priority is attempting to reduce the damage; however, knowing exactly how widespread the flooding was is necessary to evaluate computer models and plan work to mitigate further damage during future events. Unfortunately by the time the emergency response has been carried out and attention is turned to data collection, evidence and information is often no longer readily available. 

The explosion of social media in recent years has seen a greater number of recorded observations captured by the public during natural disasters that includes precise time and location information with a large geographic distribution. Using social media to solicit photos from the public during a natural disaster provides an opportunity to collect first-hand data that requires minimal effort and financial investment.

Following the widespread flooding in Christchurch on 3-5 March 2014, GHD tested the potential of social media to collect real time data. By using a social media platform, we hoped to reach people where they were – lowering the barriers to participation and broadening the audience.

All photos received through this Facebook page were geocoded, allowing the geographic spread of the data to be easily seen and overlaid with other sources of information. The results show that social media has strong promise in the collection of data during natural disaster events such as major floods.