Crowdsourcing of Twitter Social Media Data to Analyze the Hail Disaster in Surabaya

The purpose of this study is to describe the use of crowdsourcing data sources from social media, especially Twitter, in carrying out an initial analysis of an extreme weather event, in this case, hail which occurred in the city of Surabaya on February 21st, 2022. The method used in this study is data mining using data sourced from Twitter with the keywords "hujan AND es" (“Rain AND Ice”) . The initial data withdrawal was carried out twice. The first only pulled data from tweets sent from the Surabaya area and its surroundings, while the second pulled data from tweets sent from all locations. Tweet count aggregation and early tweet detection were used to estimate the time of occurrence. Extracting location data from tweets is used to map the location of the incident. Adding supporting data in the form of data on weather conditions at the time of the estimated event is carried out to enrich the information and validator information obtained through crowdsourcing on social media. Meteorological analysis was carried out at the incident's time and location based on the analysis's results using social media. The supporting data used in conducting meteorological analysis are data on air temperature, air humidity, wind speed at several locations of automatic weather stations. Based on Twitter data crowdsourcing, this study's results, hail in Surabaya on February 21st, 2022, occurred at around 14:50 Local Time (LT) and was located in the western part of Surabaya