37 research outputs found

    A fast GIS-based risk assessment for tephra fallout: the example of Cotopaxi volcano, Ecuador-Part II: vulnerability and risk assessment

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    In order to develop efficient strategies for risk mitigation and emergency management, planners require the assessment of both the expected hazard (frequency and magnitude) and the vulnerability of exposed elements. This paper presents a GIS-based methodology to produce qualitative to semi-qualitative thematic risk assessments for tephra fallout around explosive volcanoes, designed to operate with datasets of variable precision and resolution depending on data availability. Due to the constant increase in population density around volcanoes and to the wide dispersal of tephra from volcanic plumes, a large range of threats, such as roof collapses, damage to crops, blockage of vital lifelines and health problems, concern even remote communities. To address these issues, we have assessed the vulnerability and the risk levels for five themes relevant to tephra fallout: (1) social, (2) economic, (3) environmental, (4) physical and (5) territorial. Risk and vulnerability indices for each theme are averaged to the fourth level of administrative unit (parroquia, parish). In a companion paper, Biass and Bonadonna (this volume) present a probabilistic hazard assessment for tephra fallout at Cotopaxi volcano (Ecuador) using the advection-diffusion model TEPHRA2, which is based on field investigations and a global eruption database (Global Volcanism Program, GVP). The scope of this paper is to present a new approach to risk assessment specifically designed for tephra fallout, based on a comprehensive hazard assessment of Cotopaxi volcano. Our results show that an eruption of moderate magnitude (i.e. VEI 4) would result in the possible collapse of ∼9,000 houses in the two parishes located close to the volcano. Our study also reveals a high risk on agriculture, closely linked to the economic sector, and a possible accessibility problem in case of an eruption of any size, as tephra is likely to affect the only major road running from Quito to Latacunga (Panamerican Highway). As a result, this method fits into the ongoing effort to better characterize and evaluate volcanic risk, and more specifically the risk associated with tephra fallout. Although this methodology relies on some assumptions, it can serve as a rapid and efficient starting point for further investigations of the risk level around explosive volcanoe

    Preface: Geology and information technology

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    Long-term ash dispersal dataset of the Sakurajima Taisho eruption for ashfall disaster countermeasure

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    Abstract. A large volcanic eruption can generate large amounts ofash which affect the socio-economic activities of surrounding areas, affecting airline transportation, socio-economics activities, and humanhealth. Accumulated ashfall has devastating impacts on areas surrounding thevolcano and in other regions, and eruption scale and weather conditions mayescalate ashfall hazards to wider areas. It is crucial to discover placeswith a high probability of exposure to ashfall deposition. Here, as areference for ashfall disaster countermeasures, we present a datasetcontaining the estimated distributions of the ashfall deposit and airborneash concentration, obtained from a simulation of ash dispersal following alarge-scale explosive volcanic eruption. We selected the Taisho (1914)eruption of the Sakurajima volcano, as our case study. This was thestrongest eruption in Japan in the last century, and our study provides abaseline for a worst-case scenario. We employed one eruption scenario (OES)approach by replicating the actual event under various extended weatherconditions to show how it would affect contemporary Japan. We generated anash dispersal dataset by simulating the ash transport of the Taisho eruptionscenario using a volcanic ash dispersal model and meteorological reanalysisdata for 64 years (1958–2021). We explain the dataset production andprovide the dataset in multiple formats for broader audiences. We examinethe validity of the dataset, its limitations, and its uncertainties.Countermeasure strategies can be derived from this dataset to reduceashfall risk. The dataset is available at the DesignSafe-CI Data Depot:https://www.designsafe-ci.org/data/browser/public/designsafe.storage.published/PRJ-2848v2or through the following DOI: https://doi.org/10.17603/ds2-vw5f-t920by selecting Version 2 (Rahadianto and Tatano, 2020)

    Smart Collaborative Platform for eLearning with Application in Spatial Enabled Society

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    AbstractSpatially Enabled Society enables new educational opportunities and perspectives, by introducing integrative and multi-disciplinary approach in different scientific domains interconnected on a real time information platform. The paradigm proposed here is to learn at work place by doing and by collaborating at level of technology, information and the level of involved personal. As case study, we propose to develop an educational platform in urban planning field, are aiming to provide a real time data base, a network based on interchanges generated by different scientific stakeholders. Creating such a platform to build a bridge between academia and the private sector as well as interfaces between different disciplines and specialists and every citizen is still a challenge

    Volcanic risk assessment: integrating hazard and social vulnerability analysis

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    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

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

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    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

    Vulnerability of critical infrastructure to volcanic hazards

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    Volcanic eruptions produce a range of concurrent, sequential and recurrent hazards which can impact society and critical infrastructure. For daily activities, modern societies are reliant on dependable functioning critical infrastructure, such as electrical supply; water supply; wastewater; transportation; communication networks; buildings; air conditioning and ventilation systems; and electronic equipment. In addition, during volcanic eruptions these sectors are vital for effective emergency response and recovery. Despite the importance of critical infrastructure, the systematic quantification of their vulnerability to volcanic hazards, a key aspect of volcanic risk management, has received little research attention. Successful volcanic risk management and disaster risk reduction are cost effective investments in preventing future losses during eruptions and increasing resilience to volcanic hazard impacts. Effective volcanic risk management requires the characterisation of both hazards and vulnerabilities to the same level of detail. This thesis develops a methodological framework to quantitatively assess the vulnerability of critical infrastructure sectors to volcanic hazard impacts. The focus is on fragility and vulnerability functions which provide quantitative relationships between impact (damage and disruption) and volcanic hazard intensity. The framework details how post-eruption infrastructure impact data, compiled in a newly established infrastructure impacts database, can be classified by hazard and impact intensity to derive vulnerability and fragility functions. Using the vulnerability framework, fragility functions for several critical infrastructure sectors for volcanic tephra fall impacts are derived. These functions are the first attempt to quantify the vulnerability of critical infrastructure sectors using a systematic approach. Using these fragility functions, risk is estimated for the electrical transmission network in the North Island of New Zealand using a newly developed probabilistic tephra fall hazard assessment. This thesis and framework provide a pathway forward for volcanic risk scientists to advance volcanic vulnerability assessments such that comprehensive and robust quantitative volcanic risk assessments are commonplace in infrastructure management practices. Improved volcanic vulnerability and risk assessments leads to enhanced risk-based decision making, prioritisation of risk reduction investment and overall reduction in volcanic risk

    An interdisciplinary study of the hazards associated with an AD1754 style eruption of Taal Volcano, Philippines

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    Taal Volcano, 60 km south of Metro Manila in Batangas Province, is one of the most active volcanoes in the Philippines. With 33 known eruptions, Taal has caused tremendous impacts on lives, property, economy and environment. The exposure of people and assets around Taal has increased greatly in recent years with around two million people living within a 35 km radius all at risk to volcanic hazards. The risk from Taal poses multiple challenges for local volcano disaster risk reduction (DRR) efforts. This interdisciplinary study combines a synthesis and critical review of historical eruptions of Taal; physical studies (geologic mapping, stratigraphic analyses and grain size measurements of the AD1754 tephra deposit); reconstruction of tephra dispersal for the AD1754 Plinian event using TEPHRA2 inversion modelling; and consideration of the social aspects of volcanic hazard and risk (e.g. socio-economic, political and DRR contexts for Batangas Province, and a pilot study assessing the knowledge, education, awareness and preparedness of Barangay Captains who are responsible for local level volcano disaster preparedness and response). Key outputs of the research include: 1) the first single, comprehensive chronology of identified historical eruptions of Taal; 2) discovery, mapping and sampling of 41 suspected AD1754 tephra outcrops; 3) first detailed field-based verification of two of the four identified phases of this event; 4) determination of likely eruption source parameters for the AD1754 event and new tephra dispersal isopachs through inversion modelling; and 5) preliminary insights into the knowledge, awareness and preparedness of the Barangay Captains, which show that while they do take volcanic risk seriously, they are ill-prepared to effectively support their communities in the case of a major volcanic crisis at Taal. The results and recommendations are aimed at strengthening volcano disaster risk management plans for Batangas Province
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