Infrastructure impacts, management and adaptations to eruptions at Volcán Tungurahua, Ecuador, 1999-2010
This report summarises observations made on a field visit to areas affected by the May 2010 eruption of Volcán Tungurahua, Ecuador. The focus of this trip, carried out in September 2010 by a field team from the University of Canterbury and University College London, was to investigate both direct and indirect effects of ashfall on critical infrastructure, and the management of ashfall events. In particular we paid attention to less-studied areas of interest including electrical power and healthcare systems. All infrastructure topics explored aspects of resilience and adaptation, in the context of ongoing volcanic unrest at Tungurahua since 1999. Research methods were largely qualitative and included semi-structured interviews, observation, water testing and informal conversations and meetings with locals. A good overview of ashfall impacts on electricity networks, healthcare services and emergency management issues was achieved during the trip. The information gathered adds to our knowledge of the possible effects of volcanic ashfall on infrastructure and public services. Further insights into impacts of water, wastewater, transportation and agriculture were gained. Overall, infrastructure seemed to function well during the 2010 eruption, with only minor problems reported. However, the May 2010 eruption generated only minor ashfalls (a few mm) in most locations. Over the past 11 years of volcanic unrest, other events have caused more serious impacts, particularly a VEI 3 eruption on 16-17 August 2006. Electrical supplies suffered few problems, with no reports of electrical flashover from ashfalls. Problems arising from contamination of open water supplies have led to an initiative to cover water supplies. In the transport sector, the 2010 eruption resulted in a two-day closure of Guayaquil international airport due to risks to aircraft. Roads in the Tungurahua region have been frequently damaged by lahars over the past 11 years. The 2010 eruption caused partial damage to 3740 ha of crops. Far more severe, although localised, damage to crops, livestock and rural communities was caused by the August 2006 eruption. Healthcare centres are well-organised and are able to prioritise essential services in the event of an ashfall, and so experience few major impacts, but a variety of minor impacts on facilities and equipment. A variety of public health pathologies have increased by small amounts in the short term after ashfalls, and psychological impacts in communities affected by eruptions have increased since activity began at Volcán Tungurahua in 1999, and have required increased attention from healthcare professionals in the long term. Emergency management insights provide lessons pertaining to the benefits of local engagement and involvement in risk management, including the influential role of the vigìas, who act as observers of volcanic activity and coordinators of voluntary civil defence within the community. The focus on adaptations and responses to the long-term volcanic activity has provided insights into the long-term effects of volcanic activity and helped identify possible mitigation and prevention measures. It is found that in general, increased maintenance of infrastructure now occurs widely across sectors, and cleanup methods for specific sectors have been developed to cope with ashfalls. The cleanup of ash at the municipal level is well organised, and is coordinated with the National Secretariat of Risk Management such that costs are shared with the proportions adjusted according to the severity of the situation. Increased use of personal protective measures (such as masks and goggles) has achieved a reduction in 2011 GNS Science Report 2011/24 vi public health impacts. Healthcare centres are also well organised, forming brigades for rapid response in affected areas, and having a clear hierarchy of health centres within each region so that patients can be transferred if necessary. They have good knowledge of the volcanic alert level system and the protocols required for each alert level change. Emergency management also appears organised. Emergency drills are run in at-risk communities, and contingency plans are updated and revised following eruptions. Hazard warning and shelter signage is also widespread in the Tungurahua volcanic hazard area. Overall, we found clear evidence for increased organisation and improved management procedures in the Tungurahua volcanic hazard area, which should have strengthened societal resilience. Additionally individual adaptive behaviour has included: increased use of personal protective equipment, which has reduced public health effects; farmers growing more ash-resilient crops including onions, and using greenhouses for crop growth; farmers only rearing livestock for a shortened period of time in the area, in order to prevent tooth abrasion; and an initiative to cover water supplies to protect them from contamination by ashfalls. Other examples of adaptations to infrastructure have included: widespread hazard signage; sirens in and around Baños for early warning (with an alternate power supply in case of power cuts, and a contingency emergency services siren system); floodgate design at Agoyan dam for bypassing turbulent water; and the development of plans to relocate electrical transmission towers away from valleys that have, in the past, been affected by lahars. Further studies in the Tungurahua volcanic area would be beneficial, to gain long-term understanding of volcanic ash consequences on a variety of sectors, including those explored in less depth in this study.
- Science: Reports