Estimating Spatio-Temporal Risks from Volcanic Eruptions using an Agent-Based Model

Managing disasters caused by natural events, especially volcanic crises, requires a range of approaches, including risk modelling and analysis. Risk modelling is commonly conducted at the community/regional scale using GIS. However, people and objects move in response to a crisis, so static approaches cannot capture the dynamics of the risk properly, as they do not accommodate objects’ movements within time and space. The emergence of Agent-Based Modelling makes it possible to model the risk at an individual level as it evolves over space and time. We propose a new approach of Spatio-Temporal Dynamics Model of Risk (STDMR) by integrating multi-criteria evaluation (MCE) within a georeferenced agent-based model, using Mt. Merapi, Indonesia, as a case study. The model makes it possible to simulate the spatio-temporal dynamics of those at risk during a volcanic crisis. Importantly, individual vulnerability is heterogeneous and depends on the characteristics of the individuals concerned. The risk for the individuals is dynamic and changes along with the hazard and their location. The model is able to highlight a small number of high-risk spatio-temporal positions where, due to the behaviour of individuals who are evacuating the volcano and the dynamics of the hazard itself, the overall risk in those times and places is extremely high. These outcomes are extremely relevant for the stakeholders, and the work of coupling an ABM, MCE, and dynamic volcanic hazard is both novel and contextually relevant

A Spatial Agent-based Model for Volcanic Evacuation of Mt. Merapi

Natural disasters, especially volcanic eruptions, are hazardous events that frequently happen in Indonesia. As a country within the “Ring of Fire”, Indonesia has hundreds of volcanoes and Mount Merapi is the most active. Historical studies of this volcano have revealed that there is potential for a major eruption in the future. Therefore, long-term disaster management is needed. To support the disaster management, physical and socially-based research has been carried out, but there is still a gap in the development of evacuation models. This modelling is necessary to evaluate the possibility of unexpected problems in the evacuation process since the hazard occurrences and the population behaviour are uncertain. The aim of this research was to develop an agent-based model (ABM) of volcanic evacuation to improve the effectiveness of evacuation management in Merapi. Besides the potential use of the results locally in Merapi, the development process of this evacuation model contributes by advancing the knowledge of ABM development for large-scale evacuation simulation in other contexts. Its novelty lies in (1) integrating a hazard model derived from historical records of the spatial impact of eruptions, (2) formulating and validating an individual evacuation decision model in ABM based on various interrelated factors revealed from literature reviews and surveys that enable the modelling of reluctant people, (3) formulating the integration of multi-criteria evaluation (MCE) in ABM to model a spatio-temporal dynamic model of risk (STDMR) that enables representation of the changing of risk as a consequence of changing hazard level, hazard extent and movement of people, and (4) formulating an evacuation staging method based on MCE using geographic and demographic criteria. The volcanic evacuation model represents the relationships between physical and human agents, consisting of the volcano, stakeholders, the population at risk and the environment. The experimentation of several evacuation scenarios in Merapi using the developed ABM of evacuation shows that simultaneous strategy is superior in reducing the risk, but the staged scenario is the most effective in minimising the potential of road traffic problems during evacuation events in Merapi. Staged evacuation can be a good option when there is enough time to evacuate. However, if the evacuation time is limited, the simultaneous strategy is better to be implemented. Appropriate traffic management should be prepared to avoid traffic problems when the second option is chosen

Impact Forecasting to Support Emergency Management of Natural Hazards

Forecasting and early warning systems are important investments to protect lives, properties, and livelihood. While early warning systems are frequently used to predict the magnitude, location, and timing of potentially damaging events, these systems rarely provide impact estimates, such as the expected amount and distribution of physical damage, human consequences, disruption of services, or financial loss. Complementing early warning systems with impact forecasts has a twofold advantage: It would provide decision makers with richer information to take informed decisions about emergency measures and focus the attention of different disciplines on a common target. This would allow capitalizing on synergies between different disciplines and boosting the development of multihazard early warning systems. This review discusses the state of the art in impact forecasting for a wide range of natural hazards. We outline the added value of impact-based warnings compared to hazard forecasting for the emergency phase, indicate challenges and pitfalls, and synthesize the review results across hazard types most relevant for Europe

Volcanic risk assessment: integrating hazard and social vulnerability analysis

Merged with duplicate record 10026.1/867 on 12.04.2017 by CS (TIS)The vulnerability of communities at risk from volcanic activity at Volcan Tungurahua, Ecuador and Mount Rainier in the USA provided the focus for this thesis. The research aimed to develop an integrated approach to risk assessments that combined both hazard and vulnerability analysis. In phase one, the study developed a novel methodology to assess volcanic threat that utilised previously published data. This semi-quantitative approach integrated measures of both hazard and exposure factors, allowing the relative threat to different communities to be ranked. By avoiding the complex quantitative analysis associated with traditional risk assessments of the multiple hazards associated with volcanic activity, this methodology may be applied where comprehensive historic and geological data may be lacking, as well as facilitating understanding amongst non-specialists and members of the public. The second phase of the research investigated human vulnerability, with an exploratory study carried out in Ecuador. This utilised a questionnaire survey aimed at eliciting an individual’s beliefs and attitudes towards volcanic risk, which provided the basis for a more comprehensive exploration of social vulnerability conducted in the USA. This investigated further the role of socio-economic features and psychological characteristics, such as risk perception, hazard salience and self-efficacy, in promoting self-protective behaviour, and examined the relative importance of these factors in determining vulnerability. The theoretical underpinnings of this research suggest that individuals with certain socio-economic characteristics may incur greater losses during a disaster, whilst perceptual processes may influence how an individual responds to a hazardous event. Little evidence was found to support the socio-economic model of vulnerability, which prevented the integration of the two research phases. However, perceptual factors were found to be significant predictors in the adoption of protective hazard adaption. This suggests that targeting risk mitigation and communication strategies to address these psychological constructs may be more important for reducing overall vulnerability than focusing efforts towards specific socio-economic groups.ESRC/NER

Application of Geographical Information Systems to Lahar Hazard Assessment on an Active Volcanic System

Lahars (highly dynamic mixtures of volcanic debris and water) have been responsible for some of the most serious volcanic disasters and have killed tens of thousands of people in recent decades. Despite considerable lahar model development in the sciences, many research tools have proved wholly unsuitable for practical application on an active volcanic system where it is difficult to obtain field measurements. In addition, geographic information systems are tools that offer a great potential to explore, model and map hazards, but are currently under-utilised for lahar hazard assessment. This research pioneered a three-tiered approach to lahar hazard assessment on Montserrat, West Indies. Initially, requirements of potential users of lahar information (scientists and decision-makers) were established through interview and evaluated against attainable modelling outputs (given flow type and data availability). Subsequently, a digital elevation model, fit for modelling lahars, was used by a path of steepest descent algorithm and a semi-empirical debris-flow model in the prediction of lahar routes and inundation areas. Limitations of these established geographical information system (GIS) based models, for predicting the behaviour of (relatively under-studied) dilute lahars, were used to inform key parameters for a novel model, also tightly coupled to a GIS, that simulated flow routes based on change in velocity. Importantly, uncertainty in model predictions was assessed through a stochastic simulation of elevation error. Finally, the practical utility of modelling outputs (visualisations) was assessed through mutual feedback with local scientists. The new model adequately replicated past flow routes and gave preliminary predictions for velocities and travel times, thus providing a short-term lahar hazard assessment. Inundation areas were also mapped using the debris-flow model to assist long-term planning. Ultimately, a GIS can support ‘on the ground’ planning decisions, but efficacy is limited by an active volcanic system which can restrict feedback to and from end-users. *[The appendices for this thesis were submitted as separate files which could not be uploaded to the repository. Please contact the author for more information.]

The application of multivariate cluster analysis in the assessment of volcanic social vulnerability

The 20th Century was characterized by increasing human population settlement in volcanically active regions of the world. This continued growth, particularly in less developed nations, has led to an increasing exposure of households and communities more predisposed to the social and physical risks a disaster could present. This thesis proposes a new methodology for the identification, targeting and assessment of these socially vulnerable communities. Drawing from specific examples of Mount Vesuvius (Italy) and Guagua Pichincha (Ecuador), multivariate statistics are applied to population census data to characterise the frailties and assumed coping capacity of different neighbourhood types to volcanic risk. Using cluster analysis and geodemographic discriminatory techniques, results show that communities more pre-disposed to the social and economic pressures of a disaster can be identified using this method. This approach looks to enhance upon current disaster risk metrics that tend to focus on single or cumulative risk scores, rather than seeking to define the behavioural traits and attitudinal perceptions of a neighbourhood. The peripheral and often informal barrios around Quito, Ecuador are shown to be highly susceptible to volcanic social vulnerability, whilst the Campania province around Vesuvius, Italy, highlights that the greatest risk to community resilience is associated with the high density settlements along the coastal towns near the volcano. The complex nature and site-specific characteristics of volcanic hazards, as well as the cultural landscape in which a volcanic eruption takes place are found to be key determinants in all aspects of disaster reduction. Vulnerability indicators, as defined in previous studies of disaster response are often independent of each other, and in many cases, non-transferrable in different cultural settings. Similarly, vulnerability and risk perception are as much a consequence of culture and state as they are of geographical setting and the physical characteristics of a volcanic eruption. Whilst caution is advised on the application and treatment of vulnerability metrics for mitigation, examples are provided as to how a neighbourhood classification systems methodology can be practically applied for disaster risk reduction. The output of this thesis is proposed as being of direct use to disaster risk managers (DRM), civil authorities and NGOs as an alternative tool in community outreach, exposure management, disaster mitigation and disaster preparedness plans. The contribution is also discussed in the wider context of disaster risk reduction measures, recent conceptual frameworks, and ongoing global initiatives such as the United Nations’ Hyogo Framework for Action and its intended replacement, HFA2

Modeling strategies for volcanic ash dispersal and management of impacts on civil aviation

During April-May 2010, the eruption of Eyjafjallajokull volcano in Iceland caused the larger breakdown of civil aviation after World War II. Although the eruption was weak in intensity, the dispersal of volcanic ash clouds over northern and central Europe resulted in more than 100.000 flights canceled and caused over USD 1.7 billion economical losses. This event and its unexpected effects raised many questions amongst the affected communities and stakeholders. How could volcanic eruptions cause severe disruptions at continental scales? Were these impacts totally unexpected? What could have been done to improve preparedness of aviation sector and reduce societal impacts of disruptions? The harmful effects of volcanic ash on aircraft's components have long been recognized, and volcanic ash dispersal patterns can be forecasted thanks to sophisticated numerical models. However, the procedures to be implemented in case of ash-contaminated airspace where applied only in few occasions, due to the relatively low frequency of explosive eruptions events. The 2010 Eyjafjallajokull crisis revealed a low preparedness of society to direct and indirect impacts of volcanic eruptions, and pointed out some flaws to be improved for mitigating impacts of explosive eruptions on aviation operations. The issues pointed out by the 2010 crisis are the starting point of this PhD research, which aims at offering new methods for improving aviation management during explosive volcanic eruptions. This manuscript describes the novel contributions developed during a 4-year period of research. The adoption of new techniques is proposed in order to improve current tephra dispersal modeling strategies and produce results focused on aviation needs. This research develops the first methodology to assess vulnerability of air traffic system and its elements to volcanic tephra dispersal. In addition, an impact assessment methodology has been designed to estimate expected impacts of explosive volcanic eruptions on the air traffic network and its elements. The impact assessment methodology has been implemented into a map-based tool to automatically assess expected impacts of volcanic eruptions based on real ash dispersal and air traffic data. Results of the vulnerability and impact assessment can support the stakeholders involved in the definition of risk-management strategies. Contributions of this research have been applied to case-studies and specific results have been published in a collection of journal papers. Main outcomes of the research are discussed identifying further work to be done in this rapidly evolving field. This research provides useful insights to reduce impacts of volcanic eruptions on civil aviation and, eventually, on the whole society.En Abril 2010, la erupción del volcán Islandés Eyjafjallajokull causó la interrupción mas grande del tráfico aéreo en Europa desde la segunda guerra mundial. A pesar de su baja intensidad, esta erupción produjo una nube de ceniza que cubrió Europa central causando la cancelación de mas de 100.000 vuelos y perdidas económicas de más de 1.700 millones de USD. Este evento generó muchas preguntas en la opinión publica y las comunidades impactadas. ¿Pero cómo pudo una erupción volcánica provocar impactos tan fuertes a escala continental? ¿Fueron estos impactos realmente inesperados? ¿Qué se habría podido hacer para mejorar la preparación de la aviación civil? Los daños que la ceniza volcánica puede provocar en los componentes de los aviones se han documentado desde los años ochenta. También, gracias a sofisticados modelos numéricos desarrollados en las ultimas décadas, los patrones de dispersión de ceniza volcánica se pueden pronosticar. Aun así, la erupción de Eyjafjallajokull en 2010 evidenció que la sociedad no estaba preparad a lidiar con este tipo de eventos y sus impactos directos e indirectos. En Europa los procedimientos a seguir en caso de ceniza volcánica en el espacio aéreo se habían aplicado en pocas ocasiones, debido a la frecuencia relativamente baja de erupciones volcánicas explosivas. Las dificultades sufridas por los gestores del trafico aéreo en 2010 subrayan algunos aspectos a mejorar para mitigar impactos similares en el futuro. Estos aspectos son el punto de partida de esta investigación, que tiene como objetivo ofrecer nuevos métodos para mejorar la gestión del tráfico aéreo durante erupciones volcánicas explosivas. Este documento describe las contribuciones desarrolladas durante los 4 años de investigación pre-doctoral. Esta investigación propone algunas mejoras en las estrategias de modelado utilizadas actualmente para dispersión de ceniza en la atmósfera, y generar resultados que satisfagan las necesidades de la aviación civil. Se presenta la primera metodología que permite estimar la vulnerabilidad del trafico aéreo en caso de erupciones volcánicas y los impactos de la ceniza volcánica sobre sus elementos. También se ha creado una herramienta informática que permite automatizar el análisis de impactos y producir resultados utilizando datos reales de dispersión de ceniza y de trafico aéreo. Este documento discute los resultados principales de la investigación y propone directrices para su desarrollo futuro. Las contribuciones de esta investigación se han aplicado a varios casos de estudio para producir resultados específicos, y se pueden potencialmente aplicar a otras zonas. Los resultados se han presentado y discutido en un compendio de artículos científicos, publicados en revistas internacionales. Los análisis de vulnerabilidad e impacto pueden dar soporte a los actores involucrados en la gestión de trafico aéreo y la definición de estrategias para la gestión de riesgo. Sus resultados son significativos para dar soporte y definir estrategias para la gestión de riesgo. Los desarrollos futuros de esta investigación podrían utilizarse para reducir el impacto de erupciones volcánicas sobre la aviación civil, que afectan indirectamente a toda la socieda