Articles | Volume 14
04 Apr 2017
 | 04 Apr 2017

Italian codified hashtags for weather warning on Twitter – who is really using them?

Valentina Grasso, Alfonso Crisci, Marco Morabito, Paolo Nesi, Gianni Pantaleo, Imad Zaza, and Bernardo Gozzini

Abstract. During emergencies, an increasing number of messages are shared through social media platforms, becoming a primary source of information for lay people and emergency managers. Weather services and institutions have started to employ social media to deliver weather warnings even if sometimes this communication lacks in strategy. In Twitter, for example, hashtagging is very important to associate messages with certain topics; in recent years, codified hashtagging is emerging as a practical way to coordinate Twitter conversations during emergencies and quickly retrieve relevant information. In 2014, a syntax for codified hashtags for weather warning was proposed in Italy: a list of 20 hashtags, realized by combining #allertameteo (weather warning) + XXX, where final letters code the regional identification. This contribution presents a monitoring of Twitter usage of weather warning codified hashtags in Italy (since July 2015) and an analysis of different contexts. Twitter messages were retrieved using TwitterVigilance, a multi-users platform to crawl Twitter data, collect and store messages and perform quantitative analytics, about users, hashtags, tweets/retweets volumes. The Codified Hashtags data set is presented and discussed with main analytics and evaluation of regional contexts where it was successfully employed.

Short summary
Twitter has proved to be an important source of information during emergencies. In Twitter hashtags are used by users to improve information retrieval and coordinate conversations. A set of 20 hashtags to be used during weather warnings was proposed in Italy in 2014. This study presents a one-year monitoring of the Italian codified hashtags. Different regional contexts are presented and main findings are discussed. Institutions have a crucial role in the stable adoption of a codified hashtag.