Tsunami early warning chain assessment utilizing social network analysis

Abstract

Abstract The application of rapid and accurate disaster early warning information has served as the key to successful mitigation for natural disaster. For example, in a tsunami disaster condition, precise information from authorized stakeholders must be immediately and accurately conveyed to the people potentially affected by the disaster. However, in practice in the field, the disseminated information has been however uncertain, failing to reach the lowest level of society. For this reason, a study is required to identify the information network that existed in the community when the tsunami disaster occurred. One method in determining this information includes Social Network Analysis (SNA), referring to a study method of structural relationships among the interacting network members, involving: individuals, organizations, or institutions. In this study, a survey was conducted to 90 respondents at the disaster location. From the results, it was found that 14 actors were involved in disseminating information on the tsunami disaster in the lowest community. The result of the Social Network Analysis indicated that the value of the degree of centrality, actor of mosque information obtained the highest value of 0.231, implementing that most of the community at the lowest level received tsunami information from announcements disseminated through information from mosques. Meanwhile, the lowest value of network closeness centrality was hamlet (RT/RW), having a value of 0.876, indicating that information from the mosque was beneficial as disaster early warning information. Upon calculating the degree of centrality and closeness at the lowest level of society, information from mosques and hamlet (RT/RW) serves as the most influential actor in disseminating tsunami information in Pandeglang Regency, Banten, Indonesia.