Talks and presentations

Clean-up of urban areas after volcanic eruptions

September 07, 2018

Talk, Cities on Volcanoes, Naples, Italy, Cities on Volcanoes, Naples, Italy

A ubiquitous challenge of disaster response and recovery is managing disaster waste. Past volcanic related disasters have demonstrated that these events can create enormous volumes of different types of waste, at times overwhelming existing solid waste management systems. Despite this, disaster waste management is rarely planned prior to a disaster. When disaster waste planning is (exceptionally) conducted, volcanic hazards are often omitted – we suspect because disaster waste management is generally absent from volcanic impact and risk assessments. This omission is problematic as volcanic hazards can present unique challenges that other natural hazards (e.g. earthquake, hurricane, flooding) are unlikely to exhibit. For example, a common strategy is to simply remove hazard-related material, yet the insulating properties of lava mean it can take months to years for lava flows to completely cool down. Consequently, removal may need to be delayed or not undertaken at all. Additionally, uncertainty associated with whether an eruption is over means there can be a substantial amount of time before it is deemed sufficiently safe for personnel to enter a heavily damaged area to begin clean-up operations. Here, we present a multi-volcanic hazard assessment approach to identifying the effects of volcanic hazards on disaster waste management systems. We use case studies to explore these effects and develop a suite of semi-quantitative indicators to assist post-disaster clean-up decision-making. We demonstrate how these indicators can be used by applying them to Auckland Volcanic Field eruption scenarios for the city of Auckland, New Zealand to assess implications for disaster waste management systems. Our work will be beneficial for risk-reduction, emergency response and recovery managers to understand clean-up and restoration requirements for urban areas affected by volcanism.

Embracing deep uncertainties to transparently develop plausible eruption scenarios for volcanic impact and risk assessment

August 18, 2017

Talk, IAVCEI 2017, Portland, Oregon, USA

Volcanic eruptions are multi-hazard events that cause a variety of impacts to exposed societies. One challenge scientists face is communicating intricate interactions between various eruption hazards and societal elements. Complex eruption scenarios that include multiple likely eruption hazards have been found to be an effective tool for communicating this information. These eruption scenarios are of relevance to end-users because they provide a more in-depth picture of a potential future eruption than those analyses that focus on a single eruption hazard. However, deep uncertainties within the analysis must be addressed to unravel the multifaceted interactions between an eruption and societal elements for the development of scenarios. Deep uncertainty manifests when probabilities of an event are poorly constrained, unknown, or unknowable. How can volcanic risk analysts provide appropriate decision support when fundamental probabilistic relationships are unknown or at best poorly understood? What if you must rely on limited information or case studies to develop scenarios? What are the implications if fundamental assumptions or scientific data the analysis heavily relies on turn out to be incorrect? These are some of the challenges volcanic hazard / impact / risk analysts must overcome to develop multi-hazard volcanic eruption scenarios and impact assessments. Here, we propose a transparent and structured framework for scenario development that provides guidance for analysts to not only develop robust hazard, impact and risk scenarios in the face of deep uncertainty, but to also ensure that they accurately report and communicate findings to end-users and the research community. Our approach borrows concepts from traditional gap-analysis methodologies where we identify and rank the degree of scientific knowledge the scenarios are based on. We demonstrate how this process has been used to develop seven new eruption scenarios in the Auckland Volcanic Field.

Cleaning up urban areas after tephra fall: considerations for modelling and contingency planning

November 22, 2016

Talk, Cities on Volcanoes 9, Puerto Varas, Chile

Volcanic eruptions impact urban communities by disrupting transport systems, contaminating and damaging buildings and infrastructures, and are potentially hazardous to human health. Coordinated clean-up operations have demonstratively reduced the impacts that urban communities can experience. Therefore, prompt and effective clean-up measures are an essential component of an urban community’s response and recovery to volcanic eruptions. However, clean-up operations are seldom considered within volcanic response or contingency plans. In order to provide a starting point for communities exposed to tephra fall to begin planning for clean-up, we present the key considerations for planning clean-up operations based on a global review of clean-up operations. These considerations cover a wide range of contexts (e.g. eruption size, duration, urban fabric, and infrastructure dependencies) so that communities can adapt advice for their specific local setting. We then use this information to develop a model to assess the volume of tephra to remove during clean-up operations, as well as the potential cost and duration of eruptions within the Auckland Volcanic Field. Finally, we suggest that our approach can be undertaken to assess the potential clean-up requirements in other cities around the world exposed to tephra fall.

A multi-disciplinary approach to developing a volcanic eruption scenario and temporal evolution of impacts to critical infrastructure

June 30, 2016

Conference proceedings talk, 1st international Conference on Natural Hazards and Infrastructure, Chania, Greece

Auckland, New Zealand is the economic hub and the most populous city in New Zealand. Problematically, it is also built on the monogenetic Auckland Volcanic Field (AVF), meaning a future volcanic eruption is possible anywhere within the 360 km2 areal extent. When compared to other perils (e.g. earthquakes, floods, and hurricanes), volcanic impact and risk assessments are poorly developed. This is primarily due to volcanic eruptions having the potential to last for long durations with multiple interacting hazards occurring during an eruption sequence. To explore the consequences of an AVF eruption, we developed the ‘Mt Rūaumoko’ geophysical scenario lasting one month in duration to evaluate impacts and restoration time for various critical infrastructure sectors. To describe and quantify the impact of “Mt Rūaumoko” to Auckland’s infrastructure, we applied vulnerability models developed from 20 years of New Zealand-led volcanic impact reconnaissance trips, historical volcanic impact documentation and controlled laboratory testing. Importantly, we met with over 20 Auckland Lifelines Group members (a voluntary group of infrastructure providers in Auckland) who have a profound knowledge of Auckland’s infrastructure networks, systems requirements, and capabilities to check our level of service estimates for the entirety of the scenario. We present rail as an example of the work carried out for all infrastructure sectors. Our study is the most comprehensive consideration to date of the societal consequences of an AVF eruption and highlights the wide-ranging and surprising impacts such an event could impose on New Zealand’s largest city. Our findings will be used as a case study for the economic modelling, which will inform public policy on choices for new infrastructure resilience investments.