Codified Hashtags for Weather Warning on Twitter: an Italian Case Study

Area of Science:

• Social Media Analysis
• Emergency Communication
• Information Science

Background:

• Social media platforms are crucial information sources during emergencies.
• Codified hashtagging on Twitter aids message coordination and information retrieval.
• This study examines codified hashtags for weather warnings in Italy.

Purpose of the Study:

• To assess the effectiveness of codified hashtags in aligning formal and informal information sources during weather emergencies.
• To analyze the role of user-generated content in emergency communication.
• To evaluate the impact of institutional support on hashtag effectiveness.

Main Methods:

• Collected 35,558 tweets using specific weather warning hashtags (#allertameteoTOS, #allertameteoLIG, #allertameteoPIE) over one month.
• Analyzed tweets from 7,361 unique authors, manually coding users, hashtags, and content.
• Developed an R-package to support data analysis for this study.

Main Results:

• Tweets predominantly contained situational updates and geo-location information.
• Individual users acted as active information hubs during emergencies.
• Communication patterns varied across the three studied regions.

Conclusions:

• Codified hashtags effectively convey useful information from both formal and informal sources on Twitter.
• Institutional promotion of hashtags, as seen in Tuscany, resulted in highly focused situational updates (>90%).
• The use of codified hashtags can enhance automatic information retrieval systems during disasters.