Articles | Volume 15, issue 5
Nat. Hazards Earth Syst. Sci., 15, 947–961, 2015
Nat. Hazards Earth Syst. Sci., 15, 947–961, 2015

Research article 07 May 2015

Research article | 07 May 2015

Interdependence and dynamics of essential services in an extensive risk context: a case study in Montserrat, West Indies

V. L. Sword-Daniels1,2, T. Rossetto2, T. M. Wilson3, and S. Sargeant4 V. L. Sword-Daniels et al.
  • 1Centre for Urban Sustainability and Resilience, Department of Civil, Environmental and Geomatic Engineering, University College London, London, UK
  • 2EPICentre, Department of Civil, Environmental and Geomatic Engineering, University College London, London, UK
  • 3Department of Geological Sciences, University of Canterbury, Christchurch, New Zealand
  • 4British Geological Survey, Murchison House, West Mains Road, Edinburgh, UK

Abstract. The essential services that support urban living are complex and interdependent, and their disruption in disasters directly affects society. Yet there are few empirical studies to inform our understanding of the vulnerabilities and resilience of complex infrastructure systems in disasters.

This research takes a systems thinking approach to explore the dynamic behaviour of a network of essential services, in the presence and absence of volcanic ashfall hazards in Montserrat, West Indies. Adopting a case study methodology and qualitative methods to gather empirical data, we centre the study on the healthcare system and its interconnected network of essential services. We identify different types of relationship between sectors and develop a new interdependence classification system for analysis. Relationships are further categorised by hazard conditions, for use in extensive risk contexts.

During heightened volcanic activity, relationships between systems transform in both number and type: connections increase across the network by 41%, and adapt to increase cooperation and information sharing. Interconnections add capacities to the network, increasing the resilience of prioritised sectors. This in-depth and context-specific approach provides a new methodology for studying the dynamics of infrastructure interdependence in an extensive risk context, and can be adapted for use in other hazard contexts.

Short summary
There is a high degree of dependency between different critical infrastructures, which can pass on disruptions between interconnected sectors. This empirical study presents a new qualitative methodology for exploring the complexities of interdependent systems in a real-world context. We identify many different relationships across a network that transform in type and number when exposed to hazards, which add capacities to some sectors. This improves understanding of infrastructure resilience.
Final-revised paper