Prioritization and Interconnectivity Analysis of Critical Facilities for Volcanic Ash Risk Management in South Korea: An ANP Approach

Volcanic ash from large eruptions in and around the Korean Peninsula poses significant risks to critical facilities. This study employs the Analytic Network Process (ANP) to evaluate the relative importance and interconnectivity of different facility sectors vulnerable to volcanic ash impacts. The analysis focused on 12 facility categories grouped into three main sectors: transportation, infrastructure, and public facilities.

Historical volcanic damage cases were analyzed using data from vHub and the Global Volcanic Program (GVP), revealing that 53.8% of volcanic eruption cases involved ash-related damage. Based on this analysis and expert consultation, a network model was developed to capture the complex relationships between facility sectors. Volcanic disaster experts participated in a survey to assess the relative importance and influence relationships between different facility categories.

The results showed that transportation facilities had the highest importance (0.509), followed by infrastructure (0.354) and public facilities (0.137). Among all subcategories, aviation emerged as the most critical sector with an importance value of 0.246, significantly higher than other facilities. This was followed by electricity (0.117), broadcasting and communication (0.110), and ships and ports (0.103). The high ranking of aviation reflects South Korea's particular vulnerability to long-range ash dispersion effects, similar to the impacts observed during the 2010 Eyjafjallajökull eruption in Europe.

Interconnectivity analysis using a weighted super-matrix revealed significant cascade effects between sectors. Road damage showed substantial influence on medical facilities (42.8%), aviation (27.1%), and railways (15.2%). The electricity sector demonstrated broad impacts across all facilities, with particularly strong influences on broadcasting and communication (23.1%), medical facilities (20.4%), and railways (16.6%). Medical facilities emerged as highly dependent on other sectors, being significantly affected by disruptions to roads, water supply, and electricity.

These findings provide valuable insights for volcanic ash risk management in South Korea, where the threat primarily comes from distant volcanoes like Mount Baekdu. The results highlight the need for targeted mitigation strategies focusing on aviation and electrical infrastructure, while also considering the complex interdependencies between different facility sectors. This study contributes to the development of more effective disaster response planning and risk assessment methodologies tailored to South Korea's specific volcanic hazard context.