共查询到20条相似文献，搜索用时 31 毫秒
1.
In the context of natural hazard-related risk analyses, different concepts and comprehensions of the term risk exist. These differences are mostly subjected to the perceptions and historical backgrounds of the different scientific disciplines and results in a multitude of methodological concepts to analyse risk. The target-oriented selection and application of these concepts depend on the specific research object which is generally closely connected to the stakeholders’ interests. An obvious characteristic of the different conceptualizations is the immanent various comprehensions of vulnerability. As risk analyses from a natural scientific-technical background aim at estimating potential expositions and consequences of natural hazard events, the results can provide an appropriate decision basis for risk management strategies. Thereby, beside the preferably addressed gravitative and hydrological hazards, seismo-tectonical and especially meteorological hazard processes have been rarely considered within multi-risk analyses in an Alpine context. Hence, their comparative grading in an overall context of natural hazard risks is not quantitatively possible. The present paper focuses on both (1) the different concepts of the natural hazard risk and especially their specific expressions in the context of vulnerability and (2) the exemplary application of the natural scientific-technical risk concepts to analyse potential extreme storm losses in the Austrian Province of Tyrol. Following the corresponding general risk concept, the case study first defines the hazard potential, second estimates the exposures and damage potentials on the basis of an existing database of the stock of elements and values, and third analyses the so-called Extreme Scenario Losses (ESL) considering the structural vulnerability of the potentially affected elements at risk. Thereby, it can be shown that extreme storm events can induce losses solely to buildings and inventory in the range of EUR 100–150 million in Tyrol. However, in an overall context of potential extreme natural hazard events, the storm risk can be classified with a moderate risk potential in this province. 相似文献
2.
Ben Daoued Amine Mouhous-Voyneau Nassima Hamdi Yasser Duluc Claire-Marie Sergent Philippe 《Natural Hazards》2020,100(3):1059-1088
Many coastal urban areas and many coastal facilities must be protected against pluvial and marine floods, as their location near the sea is necessary. As part of the development of a Probabilistic Flood Hazard Approach (PFHA), several flood phenomena have to be modelled at the same time (or with an offset time) to estimate the contribution of each one. Modelling the combination and the dependence of several flooding sources is a key issue in the context of a PFHA. As coastal zones in France are densely populated, marine flooding represents a natural hazard threatening the coastal populations and facilities in several areas along the shore. Indeed, marine flooding is the most important source of coastal lowlands inundations. It is mainly generated by storm action that makes sea level rise above the tide. Furthermore, when combined with rainfall, coastal flooding can be more consequent. While there are several approaches to analyse and characterize marine flooding hazard with either extreme sea levels or intense rainfall, only few studies combine these two phenomena in a PFHA framework. Thus this study aims to develop a method for the analysis of a combined action of rainfall and sea level. This analysis is performed on the city of Le Havre, a French urban city on the English Channel coast, as a case study. In this work, we have used deterministic materials for rainfall and sea level modelling and proposed a new approach for estimating the probabilities of flooding.
相似文献3.
《Physics and Chemistry of the Earth, Part A: Solid Earth and Geodesy》2000,25(6-7):571-579
Assessments of the probability and the consequences of future volcanic activity can be critical aspects when evaluating the safety of the population and of industrial plants. A new methodology has been developed for the probabilistic modelling of volcanic hazards based on regional volcanic data that facilitates the production of probabilistic hazard maps for various volcanic scenarios (lava flows, tephra). The stochastic model is based on Cox processes and allows account to be taken of the observed temporal and spatial correlation inherent in volcanic eruptions. The model is applied to the Quaternary field of the Osteifel region where the forecast number of future eruptions and the probabilities related to the different scenarios are estimated using a Monte Carlo approach. The obtained hazard maps of future volcanic events are part of a comprehensive hazard analysis and serve as a major input for the risk analysis that will determine the consequences of forecast volcanic activity at the site. 相似文献
4.
Theo L. Hills Dr. 《GeoJournal》1982,6(2):151-156
In many parts of South America, the socio-economic condition of the population is such that in many respects the people, because of their vulnerable state, are a disaster waiting to occur. The triggering action of the disaster will be an extreme physical or biophysical event. If any advance is to be made in natural hazard management, then the focus must be upon people first. Halt the process of underdevelopment in South American societies and you have taken a major step forward in natural hazard management. The major concern of this paper is not so much with the competition for first place in hazard proneness in South America, but rather the elaboration of the total ecology of what we commonly designate as disasters, which ordinarily occur at the interface of extreme natural phenomena and vulnerable settlement patterns, and which should be seen, as the extreme situation which is implicit in the everyday condition of the population. Vulnerability is the key concept in this relationship. South American nations vary greatly in their hazard proneness, in the vulnerability of sectors in their societies, in the losses and general repercussions of hazardous events, and in their ability to cope effectively with the post-disaster situation, either alone or with international aid. 相似文献
5.
Saibal Ghosh Cees J. van Westen Emmanuel John M. Carranza Victor G. Jetten 《Landslides》2012,9(3):371-384
Landslide risk assessment is based on spatially integrating landslide hazard with exposed elements-at-risk to determine their vulnerability and to express the expected direct and indirect losses. There are three components that are relevant for expressing landslide hazard: spatial, temporal, and magnitude probabilities. At a medium-scale analysis, this is often done by first deriving a landslide susceptibility map, and to determine the three types of probabilities on the basis of landslide inventories linked to particular triggering events. The determination of spatial, temporal, and magnitude probabilities depend mainly on the availability of sufficiently complete historical records of past landslides, which in general are rare in most countries (e.g., India, etc.). In this paper, we presented an approach to use available historical information on landslide inventories for landslide hazard and risk analysis on a medium scale (1:25,000) in a perennially typical data-scarce environment in Darjeeling Himalayas (India). We demonstrate how the incompleteness in the resulting landslide database influences the various components in the calculation of specific risk of elements-at-risk (e.g., buildings, population, roads, etc.). We incorporate the uncertainties involved in the risk estimation and illustrate the range of expected losses in the form of maximum and minimum loss curves. The study demonstrates that even in data-scarce environments, quantitative landslide risk assessment is a viable option, as long as the uncertainties involved are expressed. 相似文献
6.
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8.
James C. Kelley 《Mathematical Geology》1971,3(1):43-50
Increasing attention in recent years has been devoted to the application of statistical techniques in the analysis and interpretation of geologic and oceanographic data. Equally important, but less well explored, are methods for efficient experimental design. The theory of linear programming provides plans for optimal sampling of geologic and oceanographic phenomena. Of particular significance are solutions to problems of multivariate sampling. Often, a single field sample may be analyzed for a number of oxides, or a number of minerals, or a number of textural parameters. In general, these variables differ in the degree to which they are diagnostic of changes in the phenomenon of interest, and thus they must be known with different levels of precision if they are to be useful. Similarly, the variables differ in the ease with which they may be measured. If a sampling plan is to be most efficient, it must provide the requisite levels of precision for the minimum expenditure of time and effort. Sampling for a single variable may be optimized directly. Sampling for several variables simultaneously usually introduces special difficulties, but if the objective function can be generalized to hold for all variables, solutions can be determined even in this situation. 相似文献
9.
Geologic uncertainty in a regulatory environment: An example from the potential Yucca Mountain nuclear waste repository site 总被引：1，自引：0，他引：1
Regulatory geologists are concerned with predicting the performance of sites proposed for waste disposal or for remediation of existing pollution problems. Geologic modeling of these sites requires large-scale expansion of knowledge obtained from very limited sampling. This expansion induces considerable uncertainty into the geologic models of rock properties that are required for modeling the predicted performance of the site.One method for assessing this uncertainty is through nonparametric geostatistical simulation. Simulation can produce a series of equiprobable models of a rock property of interest. Each model honors measured values at sampled locations, and each can be constructed to emulate both the univariate histogram and the spatial covariance structure of the measured data. Computing a performance model for a number of geologic simulations allows evaluation of the effects of geologic uncertainty. A site may be judged acceptable if the number of failures to meet a particular performance criterion produced by these computations is sufficiently low. A site that produces too many failures may be either unacceptable or simply inadequately described.The simulation approach to addressing geologic uncertainty is being applied to the potential high-level nuclear waste repository site at Yucca Mountain, Nevada, U.S.A. Preliminary geologic models of unsaturated permeability have been created that reproduce observed statistical properties reasonably well. A spread of unsaturated groundwater travel times has been computed that reflects the variability of those geologic models. Regions within the simulated models exhibiting the greatest variability among multiple runs are candidates for obtaining the greatest reduction in uncertainty through additional site characterization. 相似文献
10.
A number of examples are presented to substantiate that submarine landslides have occurred along most continental margins and along several volcano flanks. Their properties of importance for tsunami generation (i.e. physical dimensions, acceleration, maximum velocity, mass discharge, and travel distance) can all gain extreme values compared to their subaerial counterparts. Hence, landslide tsunamis may also be extreme and have regional impact. Landslide tsunami characteristics are discussed explaining how they may exceed tsunamis induced by megathrust earthquakes, hence representing a significant risk even though they occur more infrequently. In fact, submarine landslides may cause potentially extreme tsunami run-up heights, which may have consequences for the design of critical infrastructure often based on unjustifiably long return periods. Giant submarine landslides are rare and related to climate changes or glacial cycles, indicating that giant submarine landslide tsunami hazard is in most regions negligible compared to earthquake tsunami hazard. Large-scale debris flows surrounding active volcanoes or submarine landslides in river deltas may be more frequent. Giant volcano flank collapses at the Canary and Hawaii Islands developed in the early stages of the history of the volcanoes, and the tsunamigenic potential of these collapses is disputed. Estimations of recurrence intervals, hazard, and uncertainties with today’s methods are discussed. It is concluded that insufficient sampling and changing conditions for landslide release are major obstacles in transporting a Probabilistic Tsunami Hazard Assessment (PTHA) approach from earthquake to landslide tsunamis and that the more robust Scenario-Based Tsunami Hazard Assessment (SBTHA) approach will still be most efficient to use. Finally, the needs for data acquisition and analyses, laboratory experiments, and more sophisticated numerical modelling for improved understanding and hazard assessment of landslide tsunamis are elaborated. 相似文献
11.
Consequence analysis is, together with hazard evaluation, one of the major steps of landslide risk assessment. However, a significant discrepancy exists between the number of published landslide hazard and landslide consequence studies. While various methodologies for regional-scale hazard assessment have been developed during the last decade, studies for estimating and visualising possible landslide consequences are still limited, and those existing are often difficult to apply in practice mainly because of the lack of data on the historical damage or on landslide damage functions. In this paper, an indicator-based GIS-aided methodology is proposed with an application to regional-scale consequence analysis. The index, called Potential Damage Index, allows describing, quantifying, valuing, totalizing and visualising different types of consequences. The method allows estimating the possible damage caused by landslides by combining weighted indicators reflecting the exposure of the elements at risk. Direct (physical injury, and structural and functional damage) and indirect (socio-economic impacts) consequences are individually analysed and subsequently combined to obtain a map of total consequences due to landsliding. Geographic visualisation of the index allows the delineation of the areas exposed to any type of possible impacts that could be combined with a corresponding map displaying landslide probability of occurrence. The method has been successfully applied to analyse the present consequences in the Barcelonnette Basin (South French Alps). These maps contribute to development of adequate land use and evacuation plans, and thus are important tools for local authorities and insurance companies. 相似文献
12.
K. N. Khattri 《Journal of Earth System Science》1999,108(2):87-92
Long-term conditional probabilities of occurrence of great earthquakes along the Himalaya plate boundary seismic zone have
been estimated. The chance of occurrence of at least one great earthquake along this seismic zone over a period of 100 years
(beginning the year 1999) is estimated to be about 0.89. The 100-year probability of such an earthquake occurring in the Kashmir
seismic gap is about 0.27, in the central seismic gap about 0.52 and in the Assam gap about 0.21. The 25-year probabilities
of their occurrence in these gaps are 0.07, 0.17, and 0.05 respectively. These probability estimates may be used profitably
to assess the seismic hazard in the Himalaya and the adjoining Ganga plains. 相似文献
13.
Ivan G. Wong 《Natural Hazards》2014,72(3):1299-1309
The occurrence of several recent “extreme” earthquakes with their significant loss of life and the apparent failure to have been prepared for such disasters has raised the question of whether such events are accounted for in modern seismic hazard analyses. In light of the great 2011 Tohoku-Oki earthquake, were the questions of “how big, how bad, and how often” addressed in probabilistic seismic hazard analyses (PSHA) in Japan, one of the most earthquake-prone but most earthquake-prepared countries in the world? The guidance on how to properly perform PSHAs exists but may not be followed for a whole range of reasons, not all technical. One of the major emphases of these guidelines is that it must be recognized that there are significant uncertainties in our knowledge of earthquake processes and these uncertainties need to be fully incorporated into PSHAs. If such uncertainties are properly accounted for in PSHA, extreme events can be accounted for more often than not. This is not to say that no surprises will occur. That is the nature of trying to characterize a natural process such as earthquake generation whose properties also have random (aleatory) uncertainties. It must be stressed that no PSHA is ever final because new information and data need to be continuously monitored and addressed, often requiring an updated PSHA. 相似文献
14.
全国地质灾害趋势预测及预测图编制 总被引：13，自引：0，他引：13
区域地质灾害预测是地质灾害研究的难题。本文运用基于地理信息系统的风险评价方法对这一问题进行了探讨。将全国剖分为２７００个单元，对地质灾害进行现状评价，并与已数字化的地质灾害图件进行单要素叠加，编制了全国地质现状等值线图，在现状评价基础上，对地质灾害进行趋势预测，将降雨条件、区域地震活动、区域地壳稳定程度、区域岩组条件和人类工程活动等作为区域地质灾害演变的因素，运用模糊综合评判模型进行综合评判，编制了１：６００万中国地质灾害趋势预测图。 相似文献
15.
Owing to fragile geo-morphology, extreme climatic conditions, and densely populated settlements and rapid development activities, West Java Province is the most landslide hazardous area in Indonesia. So, a landslide risk map for this province bears a great importance such as for land-use planning. It is however widely accepted that landslide risk analysis is often difficult because of the difficulties involved in landslide hazard assessment and estimation of consequences of future landslide events. For instance, lack of multi-temporal inventory map or records of triggering events is often a major problem in landslide hazard mapping. In this study, we propose a simple technique for converting a landslide susceptibility map into a landslide hazard map, which we have employed for landslide risk analysis in one ideally hazardous part of volcanic mountains in West Java Province. The susceptibility analysis was carried out through correlation between past landslides and eight spatial parameters related to instability, i.e. slope, aspect, relative relief, distance to river, geological units, soil type, land use and distance to road. The obtained susceptibility map was validated using cross-time technique, and was collaborated with the frequency-area statistics to respond to ‘when landslide will occur’ and ‘how large it will be’. As for the judgment of the consequences of future landslides, expert opinion was used considering available literature and characteristic of the study area. We have only considered economic loss in terms of physical damage of buildings, roads and agricultural lands for the landslide risk analysis. From this study, we understand the following: (1) the hazard map obtained from conversion of the susceptibility map gives spatial probability and the area of an expected landslide will be greater than 500m2 in the next 2 years, (2) the landslide risk map shows that 24% of the total area is in high risk; 30% in moderate risk; 45% in low risk and no risk covers only 1% of the total area, and (3) the loss will be high in agricultural lands, while it will be low in the road structures and buildings. 相似文献
16.
Landslides, avalanches, floods, and other geologic hazards impair natural resources management by jeopardizing public safety,
damaging or restricting resource utilization, and necessitating expenditures for corrective measures The negative impact of
geologic hazard events can be reduced by tailoring resources management to hazard potential of an area This requires assessment
of where and how frequently the events occur National forests and other managed wildlands often lack monitoring or historical
records to compute frequency of hazard occurrence Tree-ring analysis, based on internal growth response to external events
such as tilting and abrasion, can provide frequency data Two examples of the use of tree-ring analysis to date landslide activity
illustrate advantages and limitations of the technique An example from the Fishlake National Forest in central Utah illustrates
assessment for planning purposes An example from the Sierra National Forest in east-central California shows assessment applied
to project design Many geologic hazards in addition to landslides are suited to tree-ring analysis to establish frequency
of occurrence Hazard reduction efforts in natural resources management could be enhanced by careful application of tree-ring
analysis 相似文献
17.
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
18.
We describe and give hydrological applications of a probabilistic model based on extreme value theory which can be used to study the values of a hydrologic process that exceed a certain threshold level Q
B
.This model is useful in estimating extreme events X
T
of return period T based on N years of available hydrologic record. We also present easy-to-use tables which give confidence intervals for X
T
.The hydrologic applications reported are a flood frequency analysis, a methodology for estimating flood damage, an estimation of precipitation probabilities, and a prediction of extreme tide levels. 相似文献
19.
Many natural phenomena exhibit size distributions that are power laws or power law type distributions. Power laws are specific in the sense that they can exhibit extremely long or heavy tails. The largest event in a sample from such distribution usually dominates the underlying physical or generating process (floods, earthquakes, diamond sizes and values, incomes, insurance). Often, the practitioner is faced with the difficult problem of predicting values far beyond the highest sample value and designing his system either to profit from them, or to protect against extreme quantiles. In this paper, we present a novel approach to estimating such heavy tails. The estimation of tail characteristics such as the extreme value index, extreme quantiles, and percentiles (rare events) is shown to depend primarily on the number of extreme data that are used to model the tail. Because only the most extreme data are useful for studying tails, thresholds must be selected above which the data are modeled as power laws. The mean square error (MSE) is used to select such thresholds. A semiparametric bootstrap method is developed to study estimation bias and variance and to derive confidence limits. A simulation study is performed to assess the accuracy of these confidence limits. The overall methodology is applied to the Harvard Central Moment Tensor catalog of global earthquakes. 相似文献
20.
Existing methods of evaluating the hazard posed by moraine-dammed lakes are unsystematic, subjective, and depend on the expertise
and biases of the geoscientist. In this paper, we provide a framework for making objective preliminary assessments of outburst
flood hazard in southwestern British Columbia. Our procedure relies on remote sensing methods and requires only limited knowledge
of glacial processes so that evaluations of outburst flood hazard can be incorporated into routine hazard assessments of glaciated
regions. We describe objective approaches, which incorporate existing empirical relations applicable to the study region,
for estimating outburst peak discharge, maximum volume, maximum travel distance, maximum area of inundation, and probability.
Outburst flood hazard is greatest for moderately large lakes that are impounded by large, narrow, ice-free moraine dams composed
of sedimentary rock debris and drain into steep, sediment-filled gullies above major river valleys. We demonstrate the application
of the procedure using three case studies and show that flood hazard varies, especially with major changes in lake level.
Our assessment scheme yields reproducible results and enables engineers and geoscientists to prioritize potentially hazardous
lakes for more detailed field investigation. 相似文献