基于功能的混凝土重力坝抗震风险模型研究

抗震风险评价是基于功能的抗震设计的关键问题之一。通过对大坝可能出现的抗震风险进行分析论证,在技术和经济上进行风险评估,为大坝业主提供决策依据,也可对抗震风险提出优化措施或对策。在重力坝抗震风险分析中,采用已给出的抗震破损程度划分标准,利用地震危险性分析和坝体地震易损性计算,建立了抗震风险分析模型,进行了抗震措施分析。通过金安桥混凝土重力坝抗震风险实例研究,计算得出抗震优化前后的风险概率,说明了抗震风险模型可用于混凝土重力坝的抗震风险评价。     

A comparison of selected global disaster risk assessment results

We compare country risk rankings derived from two recently published global disaster risk analyses. One set of country rankings is based on the Disaster Risk Index (DRI) developed by the United Nations Environment Program (UNEP) Division of Early Warning and Assessment Global Resource Information Database project under a contract to the United Nations Development Program (UNDP). The other is based on an index of disaster mortality risk developed by the Global Natural Disaster Risk Hotspots project implemented by Columbia University, the World Bank and associated partners. We convert data from these sources into two comparable indexes of disaster mortality risk and rank countries according to the resulting values for a set of natural hazards common to both studies. The country rankings are moderately correlated, ranging from .41 to .56 for individual hazards to .31 for multi-hazard mortality risks. We identify the top 25 countries according to the mortality risk values we recomputed from each study’s results to show the degree to which countries are highly ranked in common. The numbers of countries common to both lists for individual hazards range from 7 to 16 out of 25. The correspondence among the top 25 ranked countries is lowest for earthquakes and floods. Only 6 out of 25 countries are common to both lists in the multi-hazard case. We suggest that while the convergence in the results for some hazards is encouraging, more work is needed to improve data and methods, particularly with respect to assessing the role of vulnerability in the creation of risk and the calculation of multi-hazard risks. The views expressed are the authors’ and do not necessarily reflect those of SM2 Consulting Multi-Hazards and Risk Holistic Solutions or the United Nations Development Program.     

A disaster risk management performance index

The Risk Management Index, RMI, proposed in this paper, brings together a group of indicators that measure risk management performance and effectiveness. These indicators reflect the organizational, development, capacity and institutional actions taken to reduce vulnerability and losses in a given area, to prepare for crisis and to recover efficiently from disasters. This index is designed to assess risk management performance. It provides a quantitative measure of management based on predefined qualitative targets or benchmarks that risk management efforts should aim to achieve. The design of the RMI involved establishing a scale of achievement levels or determining the distance between current conditions and an objective threshold or conditions in a reference country, sub-national region, or city. The proposed RMI is constructed by quantifying four public policies, each of which is described by six indicators. The mentioned policies include the identification of risk, risk reduction, disaster management, and governance and financial protection. Risk identification comprises the individual perception, social representation and objective assessment; risk reduction involves the prevention and mitigation; disaster management comprises response and recovery; and, governance and financial protection policy is related to institutionalization and risk transfer. Results at the urban, national and sub-national levels, which illustrate the application of the RMI in those scales, are finally given.     

Flood risk perception and its determinants among rural households in two communities in Khyber Pakhtunkhwa,Pakistan

Natural Hazards - Risk perception plays a vital part in flood risk management and mitigation strategies. Therefore, this study aims at first to measure the risk perception of the vulnerable...     

Quantitative risk assessment of landslide by limit analysis and random fields

Risk may be estimated by multiplying the probability of failure by the consequence. This is acceptable for systems that have a single mode of failure. For systems that have multiple failure modes, such as landslides, the consequences should be assessed individually for each of the failure modes. This paper proposes a new framework of quantitative landslide risk assessment, in which consequences are assessed individually. The framework is generally applicable, and the landslide risk assessments of two typical slopes are presented.     

A spatially explicit degree-day model of Rift Valley fever transmission risk in the continental United States

A spatially explicit degree-day model was used to evaluate the risk of Rift Valley fever virus (RVFV) transmission by mosquitoes to humans and livestock within five target states in the continental United States: California, Minnesota, Nebraska, New York, and Texas. A geographic information system was used to model potential virus transmission based on a 12-day moving window assessment of the extrinsic incubation period theorized for RVFV in the United States. Risk of potential virus transmission in each state was spatially evaluated on a 10-km grid using average historical daily temperature data from 1994 to 2003. The highest levels of transmission risk occur in California and Texas, with parts of these states at risk of RVFV transmission for up to 8 months per year. Northern Minnesota, central New York, and most of coastal and high-elevation California are at low to null risk. Risk of impact to the livestock industry is greatest in California, Texas, and Nebraska. A standard global climate model was used to evaluate future risk in the year 2030 in Nebraska, and showed an increase of transmission risk days from approximately 3 to 4 months per year.     

病险水库理论分析研究进展

中国病险水库数量庞大,目前国内正有计划分步开展水库除险加固工作,除险加固的理论方法研究已成为当前研究的重要课题。在总结相关研究成果的基础上,将病险水库除险加固的研究分为理论分析方法和加固技术措施两方面,进而从风险分析与安全评价、结构分析方法以及除险加固效果量化研究三方面阐述了当前研究进展与不足。同时指出,考虑中国病险坝特点和机理的风险分析与安全评价、结构正反分析方法及除险加固效果的量化评价研究是未来病险水库除险加固理论分析研究的重点。     

Robustness of the holistic seismic risk evaluation in urban centers using the USRi

The Urban Seismic Risk index (USRi) published in a previous article (Carreño et al., Nat Hazards 40:137–172, 2007) is a composite indicator that measures risk from an integrated perspective and guides decision-making for identifying the main interdisciplinary factors of vulnerability to be reduced or intervened. The first step of the method is the evaluation of the potential physical damage (hard approach) as a result of the convolution of the seismic hazard with the physical vulnerability of buildings and infrastructure. Subsequently, a set of social context conditions that aggravate the physical effects is also considered (soft approach). According to this procedure, the physical risk index is evaluated for each unit of analysis from existing loss scenarios, whereas the total risk index is obtained by multiplying the former index by an impact factor using an aggravating coefficient, based on variables associated with the socio-economic conditions of each unit of analysis. The USRi has been developed using the underlying holistic and multi-hazard approach of the Urban Risk Index framework proposed for the evaluation of disaster risk in different megacities worldwide. This article presents the sensitivity analysis of the index to different parameters such as input data, weights and transformation functions used for the scaling or normalization of variables. This analysis has been performed using the Monte Carlo simulation to validate the robustness of this composite indicator, understanding as robustness how the cities maintain the ranking as well as predefined risk level ranges, when compared with the deterministic results of risk. Results are shown for different cities of the world.     

昆明市东川区泥石流风险性评价研究

昆明市东川区是我国最著名的泥石流分布区。基于社会经济发展的需要,联系泥石流研究的相关理论成果,使用泥石流危险性评价模型,结合GIS软件对昆明市东川区泥石流进行危险性评价,得出了昆明市东川区各乡镇的泥石流危险度。易损性评价是泥石流灾害风险性评价的一部分,根据每个乡镇的经济、人口等指标结合国内有关易损性的理论,建立东川区的泥石流易损性评价模型,从而对东川区以各乡镇为单位进行了易损性评价,得出了各乡镇的易损度。有了易损度和风险度,利用联合国提出的自然灾害风险表达式两项相乘得出了东川区的风险度。最后,使用ARCGIS9.0的制图输出功能,对该区域的泥石流风险性进行了分区和制图,给出了昆明市东川区泥石流风险性评价图,使该地区的泥石流风险性评价有了新的以乡镇为单元的量化指标,更好的服务于当地防灾减灾和经济社会建设。     

Annual landslide risk and effectiveness of risk reduction measures in Shihmen watershed,Taiwan

Landslide risk analysis procedures in this study could evaluate annual landslide risk, and assess the effectiveness of measures. Risk analysis encompassing landslide hazard, vulnerability, and resilience capacity was used to evaluate annual landslide risk. First, landslide spatial, temporal, and area probabilities were joined to estimate annual probability of landslides with an area exceeding a certain threshold in each slope unit. Second, different elements were assigned corresponding values and vulnerabilities to calculate the expected property and life losses. Third, the resilience capacities of communities were calculated based on the scores obtained through community checklists and the weights of items, including “the participation experience of disaster prevention drill,” “real-time monitoring mechanism of community,” “autonomous monitoring of residents,” and “disaster prevention volunteer.” Finally, the annual landslide probabilities, expected losses, and resilience capacities were combined to evaluate annual landslide risk in Shihmen watershed. In addition, annual risks before and after the implementation of measures were compared to determine the benefits of measures, and subsequently benefit–cost analysis was performed. Communities with high benefit–cost ratios included Hualing, Yisheng, Siouluan, and Gaoyi. The watershed as a whole had a benefit–cost ratio far greater than 1, indicating the effectiveness of measures was greater than the investment cost. The results of factor sensitivity analysis revealed changes in vulnerabilities and mortality rates would increase the uncertainty of risk, and that raise in annual interest rates or reduction in life cycle of measures would decrease the benefit–cost ratio. However, these changes did not reverse the cost-effective inference.     

A novel strategy to determine the insurance and risk control plan for natural disaster risk management

This study presents an extended framework for the analysis of economic effects of natural disaster risk management. It also attempts to define and evaluate the optimal insurance arrangements. A model, the economic utility constrained-maximization model, is proposed. The purpose of this study is to establish a strategy for determining an insurance and risk control plan in which consideration is given to balancing the economic effects (e.g., decrease in costs due to damage) by disaster mitigation. Furthermore, these values are compared with risk control actions for purposes of prioritization, to provide data to help evaluate the benefit of each risk control action. Disaster insurance policy premiums in contrast are based on actuarial data taken from situations in which risk control measures are not employed. This can make such contracts unfair to responsible enterprise managers who must take risk control measures. This represents an unfair aspect of insurance policies. Enterprise managers should be able to determine the optimum arrangement between natural disaster risk control and insurance given their budget limitations. The optimal strategies aim at the best applicability and balance between risk control and insurance capability for the enterprise manager. Risk control measures can generate several risk control options for enterprise managers. Premium discounts by insurers are given in this model.     

Seismic risk assessment and mapping at different levels

In 2012, the damage costs of floods in Russia amounted to about €300m, and these floods have caused nearly 200 fatalities (Kotlyakov et al. in Reg Res Rus 3(1):32–39, 2013). Risk assessment is one of the most pressing scientific topics in Russia, but most of the works are devoted to natural hazards assessment. The purpose of this work is to estimate the influence of hazardous hydrological phenomena on society. The field research was conducted in the Slavyansk municipal district in the Krasnodar region (the south-western part of Russia), which is a highly populated coastal territory with a high frequency of hazardous hydrological events. Modified methods of the Ministry of the Russian Federation for Affairs for Civil Defence, Emergencies and Elimination of Consequences of Natural Disasters (EMERCOM) were used for potential economic damage calculation. The paper did not only focus on direct, tangible risks, but also included social risk (i.e. risk to life and health). Social vulnerability has been calculated directly as a percentage of vulnerable people, estimated in opinion polls, while in many recent papers the social vulnerability index was calculated as a combination of several statistical indicators. The resulting percentage of vulnerable people was converted to numbers of potential victims. Finally, the social risk was expressed by financial indicators in terms of the cost of the value of statistical life lost (Mrozek and Taylor in J Policy Anal Manag 21(2):253–270, 2002; Viscusi and Aldy in J Risk Uncertain 27(1):5–76, 2003). Social risk can be underestimated in comparison with economic risk because of a low “value of life” in Russia (no life insurance, neglecting of basic safety rules, etc.) (Guriev in Myths of economics, Alpina Business Books, Moscow, 2009).     

A new rating system approach for risk analysis of rock slopes

In this paper, an approach is presented to analyze the stability risk of rock slopes based on a new rating system. Three factors are used to estimate the risk level of rock slopes: (1) failure probability, (2) element at risk rating, and (3) vulnerability rating. Element at risk and vulnerability ratings are both given a range from 0 to 10, and the probability of failure is varied between 0 and 1, so the risk rating ranges between 0 and 100. This risk rating can be used to determine both the quantitative and qualitative risk levels of slopes at the same time. The method is tested on the western sector of the slopes facing Songun copper plant phase III, Iran, to clarify its procedures and assess its validity. Deterministic kinematic analyses showed that the slope has a potential for circular failure. Risk assessments revealed that the risk levels of the slope in both static and pseudo-static conditions are “very low” and “high,” respectively.

     

A statistical approach to landslide risk modelling at basin scale: from landslide susceptibility to quantitative risk assessment

A procedure for landslide risk assessment is presented. The underlying hypothesis is that statistical relationships between past landslide occurrences and conditioning variables can be used to develop landslide susceptibility, hazard and risk models. The latter require also data on past damages. Landslides occurred during the last 50 years and subsequent damages were analysed. Landslide susceptibility models were obtained by means of Spatial Data Analysis techniques and independently validated. Scenarios defined on the basis of past landslide frequency and magnitude were used to transform susceptibility into quantitative hazard models. To assess vulnerability, a detailed inventory of exposed elements (infrastructures, buildings, land resources) was carried out. Vulnerability values (0–1) were obtained by comparing damages experienced in the past by each type of element with its actual value. Quantitative risk models, with a monetary meaning, were obtained for each element by integrating landslide hazard and vulnerability models. Landslide risk models showing the expected losses for the next 50 years were thus obtained for the different scenarios. Risk values obtained are not precise predictions of future losses but rather a means to identify areas where damages are likely to be greater and require priority for mitigation actions.     

A new rating system approach for risk analysis of rock slopes

In this paper, an approach is presented to analyze the stability risk of rock slopes based on a new rating system. Three factors are used to estimate the risk level of rock slopes: (1) failure probability, (2) element at risk rating, and (3) vulnerability rating. Element at risk and vulnerability ratings are both given a range from 0 to 10, and the probability of failure is varied between 0 and 1, so the risk rating ranges between 0 and 100. This risk rating can be used to determine both the quantitative and qualitative risk levels of slopes at the same time. The method is tested on the western sector of the slopes facing Songun copper plant phase III, Iran, to clarify its procedures and assess its validity. Deterministic kinematic analyses showed that the slope has a potential for circular failure. Risk assessments revealed that the risk levels of the slope in both static and pseudo-static conditions are “very low” and “high,” respectively.     

考虑时间效应的滑坡风险评估和管理

提出了考虑时间效应的滑坡风险评估和管理方法。以香港地区近20年的16 000个切破的观测资料为基础,从统计学的角度提出了边坡的时变可靠性分析方法。推导了新建边坡在未来服役时间内的年失效概率的计算公式,并对现役边坡在未来服役时间内的年失效概率进行了预测。确定了基于年死亡人数的滑坡风险接受准则,并分析了基于滑坡时变风险的边坡加固时间。结果表明,考虑时间效应的滑坡风险评估和管理方法能够更加真实地反映滑坡随时间变化的特性。新建边坡的年失效概率随边坡服役时间逐渐增大,尤其是当边坡服役超过10年时,每年发生滑坡的概率急剧增大。现役边坡的年失效概率基本与继续服役时间呈线形关系。此外,香港斜坡维修指南规定的边坡加固时间能够有效地将滑坡风险降低到ALARP区或可接受的风险区。     

盐岩地下储气库风险分级机制初探

能源储备是国家重大战略需求,目前国内已经开始大规模兴建盐岩能源地下储库群,由于国内的盐岩储库地层具有埋深浅、盐层薄、夹层多、品位低等特点,导致建库难度大、运行风险高,因此,开展盐岩地下油气储库风险分析研究具有重要的理论意义和工程应用价值。针对国内盐岩地下油气储库现状,在风险分析中引入功能设计理念,以体积收缩率作为储库运营期风险的单项分级指标,初步提出了地下油气储库运营风险分级机制的基本方法,以国内某盐岩地下储气库为例,通过流变计算获得不同储气内压变化条件下,储库风险随时间的变化规律,较好地验证了所提方法的合理性和有效性。     

Earthquake risk to industry in Istanbul and its management

Istanbul is home to 40% of the industrial facilities in Turkey. Thirty percent of the population working in industry lives in the city. Past earthquakes have evidenced that the structural reliability of residential and industrial buildings in the country is questionable. In the Marmara region the earthquake hazard is very high with a 2% annual probability of occurrence of a magnitude 7+ earthquake on the main Marmara fault. These facts make the management of industrial risks imperative for the reduction of socioeconomic losses. In this paper we present a first-order assessment of earthquake damage to the industry in Istanbul and raise issues for better characterization and quantification of industrial losses and management of urban industrial risks. This paper borrows from the project report entitled ‘Earthquake Risk Assessment for Industrial Facilities in Istanbul’. The full report can be found at http://www.koeri.boun.edu.tr/depremmuh.html under the link ‘Research and Applied Projects’.     

Toward a disaster risk assessment and mapping in the virtual geographic environment of Armenia

This paper presents the results of a research aiming natural and technological hazard, and risk assessment and mapping in Web-based holistic geographic environment, and the implementation of the Sendai Framework for Disaster Risk Reduction 2015–2030 in Armenia. A common spatial multi-criteria evaluation method was used for natural and technological hazard, risk and population vulnerability assessments. The virtual geographic environment developed by the authors during the previous period of investigations was upgraded and used for the implementation of this research. It involves the following components: 1. geodatabase, 2. modeling and simulation, 3. interface for digital mapping, 4. metadata, 5. Web–based network service for collaboration. Moreover, the country specific natural and technological hazard, risk and population vulnerability assessment methods were developed, implemented, and appropriate digital maps were created.     

Hurricane wind risk in Louisiana

A statistical procedure for estimating the risk of strong winds from hurricanes, known as the Hurricane Risk Calculator, is demonstrated and applied to several major cities in Louisiana. The procedure provides an estimate of wind risk over different length periods and can be applied to any location experiencing this hazard. Results show that an area 100 km around the city of New Orleans can expect to see hurricane winds blowing at 49 ms^?1 (44.3–53.7) [90 % confidence interval (CI)] or stronger, on average, once every 20 years. In comparison, for the same time period, the capital city of Baton Rouge and the surrounding area can expect to see hurricane winds of 43 ms^?1 (38.2–47.8) (90 % CI) or stronger. Hurricane track direction is also analyzed at the cities of interest. For Morgan City, Lafayette, Lake Charles, and Alexandria, tropical cyclones with winds at least 18 ms^?1 travel from the southeast to northwest. New Orleans and Baton Rouge tropical cyclones have a greater tendency to turn toward the east while within 100 km of the city, historically giving them a southwesterly approach. Tropical cyclones within 350 km off the south-central Louisiana coast occur most often in September, and the most extreme of these events are becoming stronger through time as shown with quantile regression.