An information network analysis approach to assessing the processes of issuing evacuation instructions: a study of evacuation cases in Japan

Issuance of evacuation instructions is a complex process based on a multifaceted decision-making process involving various stakeholders and information. This study presents a network analysis framework to statistically understand the types of stakeholders involved and the necessary information to be transmitted among them in the decision-making process for issuing evacuation instructions. The framework identifies the roles of stakeholders and the characteristics of information types involved in issuing evacuation instructions. An illustrative case study involving 215 disaster cases was conducted to demonstrate the modeling framework. Through analysis of these cases, 18 types of stakeholders and 20 types of information relevant to evacuation decision-making were identified. Nonlinear interdependencies of causation and topological characteristics among the stakeholders and information types were delineated, revealing an information network with 18 nodes and 200 links. Information flows among stakeholders were identified and visualized, and cohesive subgroups of significant stakeholders and information types were identified respectively. These significant stakeholders and information types play central roles that collectively contribute substantially to the decision-making processes involved in issuing evacuation instructions. This study provides insights into information flow dynamics and enhances understanding of decision-making topologies among stakeholders in the issuance of evacuation instructions. Statistical network analysis reveals occurrence frequencies and interdependency strengths, enriching comprehension of evacuation management processes. The findings underscore opportunities to enhance decision-making efficiency by focusing on critical stakeholders and information, thereby facilitating timely issuance of evacuation instructions.A network diagram is constructed to represent the decision-making process in issuing evacuation instructions.The frequency and looping of interdependencies in decision-making are investigated.Significant stakeholders and the information required for issuing evacuation instructions are identified.Cohesive subgroups of stakeholders and information are revealed.The modeling framework is illustrated through a case study.