Can Social Media Enable Flood Risk Mitigation? Evidence using propensity score matching

Abstract:

This study is the first to investigate the role of social media in enabling households to reduce disaster losses. The historic 2011 Bangkok flood is utilized as a case study. This event was one of the first major disasters to affect an urban area with a substantial population connected to social media. The role of online information is investigated with a mixed methods approach, using both quantitative (propensity score matching) and qualitative (in-depth interviews) techniques. The study relies on two data sources – survey responses from 469 Bangkok households and in-depth interviews with twenty-three internet users who are a subset of the survey participants.

Propensity score matching indicates that social media use enabled households to reduce mean total losses by 37%, using a nearest neighbor estimator. Average loss reductions amounted to USD 3,708 to USD 4,886, depending on the matching estimator.

Social media offered information that was not available from other sources, such as localized and nearly real-time updates of flood location and depth. With knowledge of current flood conditions, Bangkok households could move belongings to higher ground before floodwaters arrived. These findings suggest that utilizing social media users as sensors could better inform populations during natural disasters, particularly in locations that lack real-time, accurate flood monitoring networks. Expanded access to social media might be useful in developing countries, ungauged basins, and complex urban environments. Overall, the study reveals that online information can enable effective disaster preparedness and reduce flood losses.