Leveraging publicly available tweets or other social media posts could help disaster response agencies quickly identify impacted areas in need of assistance, says a new study.
By analysing the September 2013 floods in Colorado, US, the researchers showed that a combination of remote sensing, Twitter and Flickr data could be used to identify flooded areas.
"FEMA (the Federal Emergency Management Agency), the Red Cross and other response agencies use social media now to disseminate relevant information to the general public," said Guido Cervone, associate professor of geography at Pennsylvania State University (Penn State).
"We have seen here that there is potential to use social media data from community members to help identify hotspots in need of aid, especially when it is paired with remote sensing imagery of the area," Cervone noted.
After a disaster, response teams typically prioritise rescue and aid efforts with help from imagery and other data that show what regions are affected the most.
Responders commonly use satellite imagery, but this on its own has drawbacks.
"Publicly available satellite imagery for a location isn't always available in a timely manner -- sometimes it can take days before it becomes available," Elena Sava from Penn State explained.
The 2013 Colorado flooding was an unprecedented event. In nine days in September, the region received nearly the same amount of rainfall it normally receives in a year. Officials evacuated more than 10,000 people and had to rescue several thousand people and pets.
Because the flooding occurred in an urban setting, the researchers were able to access more than 150,000 tweets from people affected by the flooding.
The findings, published in the International Journal of Remote Sensing, confirmed that Twitter data could serve to identify hotspots for which satellite imagery should be acquired.
