共查询到20条相似文献，搜索用时 31 毫秒
1.
Basic principles of multi-risk assessment: a case study in Italy 总被引：3，自引：3，他引：0
Warner Marzocchi Alexander Garcia-Aristizabal Paolo Gasparini Maria Laura Mastellone Angela Di Ruocco 《Natural Hazards》2012,62(2):551-573
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. 相似文献
2.
Dynamic risk processes, which involve interactions at the hazard and risk levels, have yet to be clearly understood and properly integrated into probabilistic risk assessment. While much attention has been given to this aspect lately, most studies remain limited to a small number of site-specific multi-risk scenarios. We present a generic probabilistic framework based on the sequential Monte Carlo Method to implement coinciding events and triggered chains of events (using a variant of a Markov chain), as well as time-variant vulnerability and exposure. We consider generic perils based on analogies with real ones, natural and man-made. Each simulated time series corresponds to one risk scenario, and the analysis of multiple time series allows for the probabilistic assessment of losses and for the recognition of more or less probable risk paths, including extremes or low-probability–high-consequences chains of events. We find that extreme events can be captured by adding more knowledge on potential interaction processes using in a brick-by-brick approach. We introduce the concept of risk migration matrix to evaluate how multi-risk participates to the emergence of extremes, and we show that risk migration (i.e., clustering of losses) and risk amplification (i.e., loss amplification at higher losses) are the two main causes for their occurrence. 相似文献
3.
Jacopo Selva 《Natural Hazards》2013,67(2):701-722
Multi-risk approaches have been recently proposed to assess and compare different risks in the same target area. The key points of multi-risk assessment are the development of homogeneous risk definitions and the treatment of risk interaction. The lack of treatment of interaction may lead to significant biases and thus to erroneous risk hierarchization, which is one of primary output of risk assessments for decision makers. In this paper, a formal statistical model is developed to treat interaction between two different hazardous phenomena in long-term multi-risk assessments, accounting for possible effects of interaction at hazard, vulnerability and exposure levels. The applicability of the methodology is demonstrated through two illustrative examples, dealing with the influence of (1) volcanic ash in seismic risk and (2) local earthquakes in tsunami risk. In these applications, the bias in single-risk estimation induced by the assumption of independence among risks is explicitly assessed. An extensive application of this methodology at regional and sub-regional scale would allow to identify when and where a given interaction has significant effects in long-term risk assessments, and thus, it should be considered in multi-risk analyses and risks hierarchization. 相似文献
4.
A systematic approach for the assessment of flooding hazard and risk associated with a landslide dam
Sheng-Hsueh Yang Yii-Wen Pan Jia-Jyun Dong Keh-Chia Yeh Jyh-Jong Liao 《Natural Hazards》2013,65(1):41-62
Inundation caused by landslide dams may occur in the upstream and downstream of the dams. A proper flooding hazard assessment is required for reaction planning and decision-making to mitigate possible flooding hazards caused by landslide dams. Both quick and detailed procedures can be used to evaluate inundation hazards, depending on the available time and information. This paper presents a systematic approach for the assessment of inundation hazards and risks caused by landslide dam formation and breaches. The approach includes the evaluation of dam-breach probability, assessment of upstream inundation hazard, assessment of downstream inundation hazard, and the classification of flooding risk. The proposed assessment of upstream inundation estimates the potential region of inundation and predicts the overtopping time. The risk level of downstream flooding is evaluated using a joint consideration of the breach probability of a landslide dam and the level of flooding hazard, which is classified using a flooding hazard index that indicates the risk of potential inundation. This paper proposes both quick and detailed procedures for the assessments of inundation in both the upstream and downstream of a landslide dam. An example of a landslide dam case study in southern Taiwan was used to demonstrate the applicability of the systematic approach. 相似文献
5.
Heidi Kreibich Philip Bubeck Michael Kunz Holger Mahlke Stefano Parolai Bijan Khazai James Daniell Tobia Lakes Kai Schröter 《Natural Hazards》2014,74(3):2279-2304
Although Germany is not among the most hazard-prone regions of the world, it does experience various natural hazards that have caused considerable economic and human losses in the past. Moreover, risk due to natural hazards is expected to increase in several regions of Germany if efficient risk management is not able to accommodate global changes. The most important natural hazards, in terms of past human and economic damage they caused, are storms, floods, extreme temperatures and earthquakes. They all show a pronounced spatial and temporal variability. In the present article, a review of these natural hazards, associated risks and their management in Germany is provided. This review reveals that event and risk analyses, as well as risk management, predominantly focus on one single hazard, generally not considering the cascading and conjoint effects in a full multi-hazard and risks approach. However, risk management would need integrated multi-risk analyses to identify, understand, quantify and compare different natural hazards and their impacts, as well as their interactions. 相似文献
6.
G. Grünthal A. H. Thieken J. Schwarz K. S. Radtke A. Smolka B. Merz 《Natural Hazards》2006,38(1-2):21-44
In this paper a methodology for a multi-risk assessment of an urban area is introduced and performed for the city of Cologne,
Germany, considering the natural hazards windstorm, flooding and earthquake. Moreover, sources of the uncertainty in the analysis
and future needs for research are identified. For each peril the following analyses were undertaken: hazard assessment, vulnerability
assessment and estimation of losses. To compare the three hazard types on a consistent basis, a common economic assessment
of exposed assets was developed. This was used to calculate direct economic losses to buildings and their contents. The perils
were compared by risk curves showing the exceedence probability of the estimated losses. In Cologne, most of the losses that
occur frequently are due to floods and windstorms. For lower return periods (10–200 years) the risk is dominated by floods.
For return periods of more than 200 years the highest damage is caused by earthquakes. 相似文献
7.
Johannes Klein Jaana Jarva Dmitry Frank-Kamenetsky Igor Bogatyrev 《Environmental Earth Sciences》2013,70(4):1629-1645
The current active development of the city of St. Petersburg in Russia has led to high growth rates in both industrial and housing areas, causing an increased load on geological media. Taking into account the rather unfavourable geological conditions of the city area, such a development can entail to an intensification of environmental risks. Sustainable and cost-effective land-use planning requires information on geological conditions. Stakeholders need general geological information on the area of St. Petersburg, hydrogeological information on groundwater and information on geological risks. Geological risk maps help to identify whether an area under consideration requires special measures for geological risk management. This paper describes a first attempt to analyze potential geological risks in the city of St. Petersburg, Russia. The approach is to introduce a methodology for multi-risk assessment to be used in land-use planning. The core of the methodology is a matrix that assigns a certain level of geological risk depending on the combination of land use stipulated by the master plan of St. Petersburg and geological characteristics. Based on the matrix, a map presenting potential integrated geological risk can be created. At the same time, the combination of the integrated geological risk map, single geological risk maps and the matrix allows the retracement of which geological characteristics and which land use types contribute to the resulting risk. Users of the methodology in St. Petersburg were trained and an end-user manual was prepared by the authors. The methodology was introduced to professionals who utilize geological information and assess potential risks related to geology. 相似文献
8.
《Applied Geochemistry》2002,17(8):1029-1045
The advantages of quantitative environmental risk assessment techniques over the more commonly used qualitative approach is widely accepted. Yet, correct implementation of quantitative risk assessment is a difficult task, given the present state of understanding of the environmental processes. One important parameter related to the level of risk is the extent and geographic spread of pollutants. Geographic information systems (GIS) provide a very powerful and highly flexible tool that increases the sophistication of the risk assessment methodology. Through spatial representation, the estimated risk becomes more comprehensive, thus facilitating the decision making process. In addition, valuable qualitative information can be incorporated into the risk assessment procedure with the help of GIS. This paper illustrates a methodology which incorporates a probabilistic risk assessment model within a GIS. The case study utilised to illustrate the methodology is a large industrial area around a number of decommissioned minerals production and processing sites with known high heavy metal loads at Lavrio, Greece. The spatial distribution of Pb concentration in soils was derived from 425 soil samples collected over a total area of 120 km2. A risk assessment model was constructed to simulate and assess the risk associated with high Pb loads in soils in the study area. The methodology consists of a typical exposure assessment model, constructed for adult and child populations. The Pb exposure for both populations is compared with relevant reference dose levels providing hazard quotients. The results of the quantitative risk assessment study are analysed and presented in the form of GIS maps covering the study area. 相似文献
9.
Preliminary flood risk assessment: the case of Athens 总被引：3，自引：2，他引：1
Flood mapping, especially in urban areas, is a demanding task requiring substantial (and usually unavailable) data. However,
with the recent introduction of the EU Floods Directive (2007/60/EC), the need for reliable, but cost effective, risk mapping
at the regional scale is rising in the policy agenda. Methods are therefore required to allow for efficiently undertaking
what the Directive terms “preliminary flood risk assessment,” in other words a screening of areas that could potentially be
at risk of flooding and that consequently merit more detailed attention and analysis. Such methods cannot rely on modeling,
as this would require more data and effort that is reasonable for this high-level, screening phase. This is especially true
in urban areas, where modeling requires knowledge of the detailed urban terrain, the drainage networks, and their interactions.
A GIS-based multicriteria flood risk assessment methodology was therefore developed and applied for the mapping of flood risk
in urban areas. This approach quantifies the spatial distribution of flood risk and is able to deal with uncertainties in
criteria values and to examine their influence on the overall flood risk assessment. It can further assess the spatially variable
reliability of the resulting maps on the basis of the choice of method used to develop the maps. The approach is applied to
the Greater Athens area and validated for its central and most urban part. A GIS database of economic, social, and environmental
criteria contributing to flood risk was created. Three different multicriteria decision rules (Analytical Hierarchy Process,
Weighted Linear Combination and Ordered Weighting Averaging) were applied, to produce the overall flood risk map of the area.
To implement this methodology, the IDRISI Andes GIS software was customized and used. It is concluded that the results of
the analysis are a reasonable representation of actual flood risk, on the basis of their comparison with historical flood
events. 相似文献
10.
This paper presents an assessment of the avalanche hazard potential and the resulting risks on mountain roads for a 38.7-km-long
section of road no 76 (Siglufjarearvegur) in northern Iceland following a regional scale approach developed in the Alps. The
assessment of the individual avalanche death risk proved applicable to distinguish areas of avalanche hazard with a risk above
the accepted level, which should be given priority in following detailed investigations and the planning of possible protective
measures, from road sections where the avalanche death risk is low and accepted according to international practice. The cumulative
individual and collective avalanche death risks in the investigated road section provide a comparable measure for assessing
the avalanche hazard both within the Icelandic public road network and on an international scale. The case study on road no
76 in northern Iceland shows that a standardised regional scale risk-based approach is practical to determine, analyse and
assess the avalanche hazard situation on mountain roads in Iceland and guarantees comprehensible, reproducible and comparable
results as a basis for a sustainable planning of measures. 相似文献
11.
Vulnerability, hazards and multiple risk assessment for Georgia 总被引：2，自引：1，他引：1
Otar Varazanashvili Nino Tsereteli Avtandil Amiranashvili Emil Tsereteli Elizbar Elizbarashvili Jemal Dolidze Lado Qaldani Manana Saluqvadze Shota Adamia Nika Arevadze Aleksandre Gventcadze 《Natural Hazards》2012,64(3):2021-2056
12.
13.
Renato Macciotta C. Derek Martin Norbert R. Morgenstern David M. Cruden 《Landslides》2016,13(4):765-785
The benefits of quantitative risk assessments for landslide management have been discussed and illustrated in several publications. However, there still are some challenges in its application for low-probability, high-magnitude events. These challenges are associated with the difficulties in populating our models for risk calculations, which largely require the input of expert opinion. This paper presents a quantitative risk assessment to a very slow moving rock slope within a dam reservoir in the Province of British Columbia, Canada. The assessment is focused on the risk to the population in the vicinity of the dam and the populated areas downstream. Expert opinions quantified the slope failure probabilities in the order of 10?3 to 10?1 per year for the smallest failure scenario considered and less than 10?6 for a failure of the entire slope. However, these estimations are associated with high levels of uncertainty. Our approach starts with the calculation and assessment of the magnitude and probability of the potential slope failure consequences, minimizing the uncertainties associated with estimated slope failure probabilities. Then, these consequences and failure probabilities are combined to obtain a measure of risk. The uncertainty associated with the slope failure probabilities is managed by the estimation of plausible ranges for these. The calculated risk levels are then presented as ranges of values and assessed against adopted evaluation criteria. The consequence and risk assessment of the rock slope suggest that the risk to the population exposed in the vicinity of the dam and populated areas downstream is under adequate control. The probability of large consequence scenarios is extremely low, in the order of 10?7 chance of an event causing more than 100 fatalities. We propose an observational technique to assess changes in risk levels and decide when to update the risk management approach or deploy emergency measures. The technique is focused on the detection of changes in the slope deformation patterns that would indicate an increase in the potential failure volumes or an imminent failure. It can be considered an extension to the current early warning system in place, easy to implement and enhanced with the strength of the comprehensive analysis required for a quantitative risk assessment. 相似文献
14.
Components of geostatistical estimation, developed as a method for ore deposit assessment, are discussed in detail. The assumption that spatial observations can be treated as a stochastic process is judged to be an inappropriate model for natural data. Problems of semivariogram formulation are reviewed, and this method is considered to be inadequate for estimating the function being sought. Characteristics of bivariate interpolation are summarized, highlighting kriging limitations as an interpolation method. Limitations are similar to those of inverse distance weighted observations interpolation. Attention is drawn to the local bias of kriging and misplaced claims that it is an “optimal” interpolation method. The so-called “estimation variance,” interpreted as providing confidence limits for estimation of mining blocks, is shown to be meaningless as an index of local variation. The claim that geostatistics constitutes a “new science” is examined in detail. Such novelties as exist in the method are shown to transgress accepted principles of scientific inference. Stochastic modeling in general is discussed, and purposes of the approach emphasized. For the purpose of detailed quantitative assessment it can provide only prediction qualified by hypothesis at best. Such an approach should play no part in ore deposit assessment where the need is for local detailed inventories; these can only be achieved properly through local deterministic methods, where prediction is purely deductive. 相似文献
15.
This paper is a contribution to an important aspect of the systematic and quantitative assessment of landslide hazard and risk. The focus is on site-specific and detailed assessment for rainfall-triggered landslides and, in particular, on the estimation and interpretation of the temporal probability of landsliding. Historical rainfall data over a 109-year period were analysed with particular reference to a site along the Unanderra and Moss Vale Railway Line in the State of New South Wales, Australia. It is shown that the recurrence interval of landsliding and hence annual probability of occurrence is subject to significant uncertainty and that it cannot be regarded as a constant. Accordingly landslide hazard varies spatially as well as being a function of time. For the example case study considered in this paper the annual probability of landslide occurrence was estimated to be in the range 0.026–0.172. However, the mean annual probability of landslide reactivation was estimated to be in the range 0.037–0.078. Utilisation of methods for probability assessment proposed in this paper will contribute to more realistic assessment of hazard and risk and, therefore, to more efficient risk management. 相似文献
16.
A quantitative vulnerability function for fluvial sediment transport 总被引：11，自引：6，他引：5
In quantitative risk assessment, risk is expressed as a function of hazard, elements at risk exposed, and vulnerability. Vulnerability
is defined as the expected degree of loss for an element at risk as a consequence of a certain event, following a natural-scientific
approach combined with economic methods of loss appraisal. The resulting value ranges from 0 (no damage) to 1 (complete destruction).
With respect to torrent processes, i.e., fluvial sediment transport, this concept of vulnerability—though widely acknowledged—did
not result in sound quantitative relationships between process intensities and associated degrees of loss so far, even if
considerable loss occurred during recent years. To close this gap and establish this relationship, data from three well-documented
torrent events in the Austrian Alps were used to derive a quantitative vulnerability function applicable to residential buildings
located on torrent fans. The method applied followed a spatially explicit empirical approach within a GIS environment and
was based on process intensities, the spatial characteristics of elements at risk, and average reconstruction values on a
local scale. Additionally, loss data were collected from responsible administrative bodies and analysed on an object level.
The results suggest a modified Weibull distribution to fit best to the observed damage pattern if intensity is quantified
in absolute values, and a modified Frechet distribution if intensity is quantified relatively in relation to the individual
building height. Additionally, uncertainties resulting from such an empirical approach were studied; in relation to the data
quality a 90% confidence band was found to represent the data range appropriately. The vulnerability relationship obtained
allows for an enhanced quantification of torrent risk, but also for an inclusion in comprehensive vulnerability models including
physical, social, economic, and institutional vulnerability. As a result, vulnerability to mountain hazards might decrease
in the future. 相似文献
17.
18.
This paper presents a new method for quantifying vulnerability to natural hazards in China. As an important area of vulnerability research, quantitative assessment of vulnerability has raised much focus in academia. Presently, scholars have proposed a variety of methods for quantitative assessment, which usually create an index of overall vulnerability from a suite of indicators, based on the understanding of the cause or mechanism of vulnerability. However, due to the complex nature of vulnerability, this approach caused some arguments on the indicator selection and the weight set for subindices. A data envelopment analysis?Cbased model for the assessment of the regional vulnerability to natural disasters is presented here to improve upon the traditional methods, and a new approach for the classification of vulnerability is proposed. The vulnerability to natural hazards in China??s mainland is illustrated as a case study. The result shows that the overall level of vulnerability to natural hazards in mainland China is high. The geographic pattern shows that vulnerability is highest in western China, followed by diminishing vulnerability in central China, and lowest vulnerability levels in eastern China. There is a negative correlation between the level of vulnerability and the level of regional economic development. 相似文献
19.
Flood loss analysis and quantitative risk assessment in China 总被引：9，自引：4，他引：5
Risk assessment is a prerequisite for flood risk management. Practically, most of the decision making requires that the risks and costs of all risk mitigation options are evaluated in quantified terms. Therefore, a quantitative assessment of possible flood loss is very important, especially for emergency planning and pre-disaster preparedness. This paper presents a preliminary methodology and an operational approach for assessing the risk of flood loss to the population, crops, housing, and the economy at county level in China. The present work assesses the risk of loss for each element (people, crops, and so on) under low-, moderate-, and high-intensity flood using intensity-loss curves and loss rates based on historical flood data from 1990 to 2008. Results show that the counties with high flood risk are primarily located in North, East, Central, and South China, particularly in the lower reaches of rivers. On the other hand, the risk of most counties in the western region is generally lower than that of counties in the eastern region. However, for the entire country, the high-risk regions have both a substantial amount of rainfall and low terrain, making such regions highly prone to flooding. Moreover, these high-risk regions present both high population and wealth density. 相似文献
20.
Earthquakes cluster in space and time resulting in nonlinear damage effects. We compute earthquake interactions using the Coulomb stress transfer theory and dynamic vulnerability from the concept of ductility capacity reduction. We combine both processes in the generic multi-risk framework where risk scenarios are simulated using a variant of the Markov chain Monte Carlo method. We apply the proposed approach to the thrust fault system of northern Italy, considering earthquakes with characteristic magnitudes in the range ~[6, 6.5], different levels of tectonic loading \(\dot{\tau }\) = {10?4, 10?3, 10?2} bar/year and a generic stock of fictitious low-rise buildings with different ductility capacities μ Δ = {2, 4, 6}. We describe the process’ stochasticity by non-stationary Poisson earthquake probabilities and by binomial damage state probabilities. We find that earthquake clustering yields a tail fattening of the seismic risk curve, the effect of which is amplified by damage-dependent fragility due to clustering. The impact of clustering alone is in average more important than dynamic vulnerability, the spatial extent of the former phenomenon being greater than of the latter one. 相似文献