Time filter

Source Type

Fleming K.,German Research Center for Geosciences | Parolai S.,German Research Center for Geosciences | Garcia-Aristizabal A.,Center for the Analysis and Monitoring of Environmental Risk | Tyagunov S.,TU Berlin | And 3 more authors.
Annals of Geophysics | Year: 2016

Single-type hazard and risk assessment is the usual framework followed by disaster risk reduction (DRR) practitioners. There is therefore a need to present and compare the results arising from different hazard and risk types. Here we describe a simple method for combining risk curves arising from different hazard types in order to gain a first impression of the total risk. We show how the resulting total (and individual) risk estimates can be examined and compared using so-called risk matrices, a format preferred by some DRR practitioners. We apply this approach to Cologne, Germany, which is subject to floods, windstorms and earthquakes. We then use a new series of risk calculations that consider epistemic uncertainty. The Mann-Whitney test is applied to determine if the losses arising from pairs of hazards are comparable for a given return period. This benefits decision makers as it allows a ranking of hazards with respect to expected damage. Such a comparison would assist planners in the allocation of resources towards the most efficient mitigation actions. However, the results are dependent upon the distribution of estimates (i.e., level of uncertainty), which is in turn a function of our state of knowledge. © 2016 by the Istituto Nazionale di Geofisica e Vulcanologia. All rights reserved.


Garcia-Aristizabal A.,Center for the Analysis and Monitoring of Environmental Risk | Polese M.,University of Naples Federico II | Zuccaro G.,University of Naples Federico II | Almeida M.,Center for Forest Fire Research | Aubrecht C.,AIT Austrian Institute of Technology
ISCRAM 2015 Conference Proceedings - 12th International Conference on Information Systems for Crisis Response and Management | Year: 2015

Natural or man-made disasters can trigger other negative events leading to tremendous increase of fatalities and damages. In case of Low Probability - High consequences events, decision makers are faced with very difficult choices and the availability of a tool to support emergency decisions would be very much beneficial. Within EU CRISMA project a concept model and tool for evaluating cascading effects into scenario-based analyses was implemented. This paper describes the main concepts of the model and demonstrates its application with reference to two earthquake-triggered CE scenarios, including (the first) the falling of an electric cable, ignition and spreading of forest fire and (the second) the happening of a second earthquake in a sequence. Time dependent seismic vulnerability of buildings and population exposure are also considered for updating impact estimation during an earthquake crisis.


Garcia-Aristizabal A.,Center for the Analysis and Monitoring of Environmental Risk | Bucchignani E.,Centro Euro Mediterraneao sui Cambiamenti Climatici CMCC CIRA | Palazzi E.,CNR Institute of Neuroscience | D'Onofrio D.,University of Turin | And 2 more authors.
Natural Hazards | Year: 2014

In this paper we have put forward a Bayesian framework for the analysis and testing of possible non-stationarities in extreme events. We use the extreme value theory to model temperature and precipitation data in the Dar es Salaam region, Tanzania. Temporal trends are modeled writing the location parameter of the generalized extreme value distribution in terms of deterministic functions of explanatory covariates. The analyses are performed using synthetic time series derived from a Regional Climate Model. The simulations, performed in an area around the Dar es Salaam city, Tanzania, take into account two Representative Concentration Pathways scenarios from the Intergovernmental Panel on Climate Change. Our main interest is to analyze extremes with high spatial and temporal resolution and to pursue this requirement we have adopted an individual grid box analysis approach. The approach presented in this paper is composed of the following key elements: (1) an advanced Bayesian method for the estimation of model parameters, (2) a rigorous procedure for model selection, and (3) uncertainty assessment and propagation. The results of our analyses are intended to be used for quantitative hazard and risk assessment and are presented in terms of hazard curves and probabilistic hazard maps. In the case study we found that for both the temperature and precipitation data, a linear trend in the location parameter was the only model performing better than the stationary one in the areas where evidence against the stationary model exists. © 2014, Springer Science+Business Media Dordrecht.


Salzano E.,CNR Institute for Research on Combustion | Basco A.,Center for the Analysis and Monitoring of Environmental Risk
Journal of Loss Prevention in the Process Industries | Year: 2015

The evaluation of vulnerability of process equipment to explosion is a central issue in the analysis of industrial risks. In this work, we have developed a simplified model, however based on fundamental equations, which includes structural and fluid-dynamic parameters for the target (the industrial equipment) and for the impacting pressure wave (shock waves) or object (fragment, debris) produced by different type of chemical explosions.The validity of methodology has been assessed by case histories. Several insights on the dynamic of structural interaction of the explosion with the target have been obtained, with specific reference to escalation effects.The model derives from the well-known Johnson's number, often adopted in impact engineering. © 2015 Elsevier Ltd.


Marzocchi W.,Italian National Institute of Geophysics and Volcanology | Garcia-Aristizabal A.,Center for the Analysis and Monitoring of Environmental Risk | Gasparini P.,Center for the Analysis and Monitoring of Environmental Risk | Mastellone M.L.,The Second University of Naples | Ruocco A.D.,Center for the Analysis and Monitoring of Environmental Risk
Natural Hazards | Year: 2012

The assessment of the impact of different catastrophic events in a given area requires innovative approaches that allow risks comparison and that account for all the possible risk interactions. In the common practice, the risk evaluation related to different sources is generally done through independent analyses, adopting disparate procedures and time--space resolutions. Such a strategy of risks evaluation has some evident major drawbacks as, for example, it is difficult (if not impossible) to compare the risk of different origins, and the implicit assumption of independence of the risk sources leads to neglect possible interactions among threats and/or cascade effects. The latter may amplify the overall risk, and potentially the multi-risk index could be higher than the simple aggregation of single-risk indexes calculated considering each source as independent from the others. In this paper, we put forward some basic principles for multi-risk assessment, and we consider a real application to Casalnuovo municipality (Southern Italy), in which we face the problem to make different hazards comparable, and we highlight when and how possible interactions among different threats may become important. © 2012 Springer Science+Business Media B.V.


Bucchignani E.,Meteo Systems and Instrumentation CIRA | Garcia-Aristizabal A.,Center for the Analysis and Monitoring of Environmental Risk | Montesarchio M.,Division Impact on Soil and Coasts CMCC
Vulnerability, Uncertainty, and Risk: Quantification, Mitigation, and Management - Proceedings of the 2nd International Conference on Vulnerability and Risk Analysis and Management, ICVRAM 2014 and the 6th International Symposium on Uncertainty Modeling and Analysis, ISUMA 2014 | Year: 2014

We have applied a Bayesian framework for the analysis and testing of possible non-stationarities in extreme meteorological events in an area around Ouagadougou, Burkina Faso. Considering the results obtained for the historical period (1950-2005), it can be seen that, for a given exceedance probability, the intensities of extreme temperature and extreme consecutive dry days ECDD data are positively correlated. The higher values of extreme temperature and ECDD are identified at the Eastern part of the domain. This result suggests that those areas can be more likely exposed to desertification processes. Some of these areas are also coincident with areas in which extreme rainfall events may occur, and this combination can be a factor amplifying the possibility of flood events. Looking at the effects of the two climate change scenarios considered (RCP4.5 and RCP8.5), different patterns were found for the three variables analyzed; whereas, the ECDD data indicate that the stationary model is the one that dominates most of the solutions. The extreme temperature and extreme precipitation show remarkable trends in both scenarios. In this paper, analyses of the spatial distribution of the extreme events and the temporal trends observed when considering scenarios of climate change are performed. © 2014 American Society of Civil Engineers.


Scolobig A.,International Institute For Applied Systems Analysis | Scolobig A.,ETH Zurich | Komendantova N.,International Institute For Applied Systems Analysis | Komendantova N.,ETH Zurich | And 7 more authors.
Natural Hazards | Year: 2014

Technical and institutional capacities are strongly related and must be jointly developed to guarantee effective natural risk governance. Indeed, the available technical solutions and decision support tools influence the development of institutional frameworks and disaster policies. This paper analyses technical and institutional capacities, by providing a comparative evaluation of governance systems in Italy and France. The focus is on two case studies: Naples and Guadeloupe. Both areas are exposed to multiple hazards, including earthquakes, volcanic eruptions, landslides, floods, tsunamis, fires, cyclones, and marine inundations Cascade and conjoint effects such as seismic swarms triggered by volcanic activity have also been taken into account. The research design is based on a documentary analysis of laws and policy documents informed by semi-structured interviews and focus groups with stakeholders at the local level. This leads to the identification of three sets of governance characteristics that cover the key issues of: (1) stakeholders and governance level; (2) decision support tools and mitigation measures; and (3) stakeholder cooperation and communication. The results provide an overview of the similarities and differences as well as the strengths and weaknesses of the governance systems across risks. Both case studies have developed adequate decision support tools for most of the hazards of concern. Warning systems, and the assessment of hazards and exposure are the main strengths. While technical/scientific capacities are very well developed, the main weaknesses involve the interagency communication and cooperation, and the use and dissemination of scientific knowledge when developing policies and practices. The consequences for multi-risk governance are outlined in the discussion. © 2014 Springer Science+Business Media Dordrecht.


Garcia-Aristizabal A.,Center for the Analysis and Monitoring of Environmental Risk | Selva J.,Italian National Institute of Geophysics and Volcanology | Fujita E.,Japan National Research Institute for Earth Science and Disaster Prevention
Bulletin of Volcanology | Year: 2013

Eruption forecasting refers, in general, to the assessment of the occurrence probability of a given eruptive event, whereas volcanic hazards are normally associated with the analysis of superficial and evident phenomena that usually accompany eruptions (e. g., lava, pyroclastic flows, tephra fall, lahars, etc.). Nevertheless, several hazards of volcanic origin may occur in noneruptive phases during unrest episodes. Among others, remarkable examples are gas emissions, phreatic explosions, ground deformation, and seismic swarms. Many of such events may lead to significant damages, and for this reason, the "risk" associated to unrest episodes could not be negligible with respect to eruption-related phenomena. Our main objective in this paper is to provide a quantitative framework to calculate probabilities of volcanic unrest. The mathematical framework proposed is based on the integration of stochastic models based on the analysis of eruption occurrence catalogs into a Bayesian event tree scheme for eruption forecasting and volcanic hazard assessment. Indeed, such models are based on long-term eruption catalogs and in many cases allow a more consistent analysis of long-term temporal modulations of volcanic activity. The main result of this approach is twofold: first, it allows to make inferences about the probability of volcanic unrest; second, it allows to project the results of stochastic modeling of the eruptive history of a volcano toward the probabilistic assessment of volcanic hazards. To illustrate the performance of the proposed approach, we apply it to determine probabilities of unrest at Miyakejima volcano, Japan. © 2013 Springer-Verlag Berlin Heidelberg.

Loading Center for the Analysis and Monitoring of Environmental Risk collaborators
Loading Center for the Analysis and Monitoring of Environmental Risk collaborators