Modelling Seismic Hazard in Earthquake Loss Models with Spatially Distributed Exposure

The prediction of possible future losses from earthquakes, which in many cases affect structures that are spatially distributed over a wide area, is of importance to national authorities, local governments, and the insurance and reinsurance industries. Generally, it is necessary to estimate the effects of many, or even all, potential earthquake scenarios that could impact upon these urban areas. In such cases, the purpose of the loss calculations is to estimate the annual frequency of exceedance (or the return period) of different levels of loss due to earthquakes: so-called loss exceedance curves. An attractive option for generating loss exceedance curves is to perform independent probabilistic seismic hazard assessment calculations at several locations simultaneously and to combine the losses at each site for each annual frequency of exceedance. An alternative method involves the use of multiple earthquake scenarios to generate ground motions at all sites of interest, defined through Monte–Carlo simulations based on the seismicity model. The latter procedure is conceptually sounder but considerably more time-consuming. Both procedures are applied to a case study loss model and the loss exceedance curves and average annual losses are compared to ascertain the influence of using a more theoretically robust, though computationally intensive, procedure to represent the seismic hazard in loss modelling.An erratum to this article can be found at     

地震灾害损失初步评估方法研究

通过搜集地震灾害及经济损失评估资料,研究地震灾害特征,总结经济损失规律,提取地震灾害损失评估经验模型。以此为基础,提出一种初步评估地震灾害经济损失的方法。研究震级与人员伤亡的关系,形成人员伤亡评估经验模型;采用适合本地区的人员伤亡评估经验模型,估算人员伤亡。研究历史地震烈度分布特征,根据震情速报的地点、震级初步确定地震灾区范围;按烈度分布的一般规律初步划分评估区;结合地震应急数据库统计不同评估区内房屋建筑面积,或者查阅当地年鉴统计不同评估区内人口数,按人均房屋建筑面积估算灾区房屋建筑面积;研究历史地震房屋建筑震害,给出房屋建筑地震破坏比经验模型(震害矩阵);按国家标准《地震现场工作第4部分:灾害直接损失评估》(2005)选取适合的损失比;收集不同结构类型房屋建筑的重置单价。遵循地震灾害损失评估原理,可以快速评估计算房屋建筑的地震灾害经济损失。研究历史地震中其他工程结构经济损失与地震灾害总损失的关系,给出其他工程结构经济损失占地震灾害总损失比例的经验模型,据此初步估计其他工程结构的经济损失。     

地震灾害损失评估软件开发

以基于Windows操作系统的MapX标准控件作为基本开发组件,Delphi7语言作为集成开发环境,Access作为外接数据库,考虑近年来地震灾害损失评估内容的新变化,并结合最新的地震现场工作规范和云南省地震现场工作的实际,开发了新的地震灾害损失评估软件.该软件涵盖了当前灾评计算的全部内容,输入、查询、修改、计算等界面直观、方便,计算结果可直接以Word表格形式输出,可大大节省地震灾评报告的编写时间,从而提高地震现场灾评工作的效率.     

我国电力系统地震灾害损失基本特征分析

基于1997—2017年中国大陆247次地震灾害资料,统计了电力系统在97次地震中遭受的灾害损失情况,并分析了其在不同震级地震中的灾害经济损失情况及特点。结果表明:①电力系统平均每年遭受4.6次地震灾害;②灾害性地震造成电力系统成灾占比随震级增高而增大,M<5.0、5.0≤M<5.9、6.0≤M<6.9、M≥7.0地震成灾占比分别为13.6%,38.9%,56.2%和62.5%,平均为38.5%;③电力系统地震灾害损失随地震震级增大而增大,但二者之间并非简单的线性关系;④电力系统地震灾害主要分布在我国云南、四川、新疆、甘肃等中国西部地区。     

5·12汶川地震灾评工作中的几点认识

由于汶川地震是新中国成立以来破坏性最强、地震灾害最重、救灾难度最大、波及范围最广的一次地震,在其地震灾评工作中产生了不同于以往地震灾评的诸多问题。针对这些问题,首先给出了汶川地震灾评简况。其次,简单说明了作者参加灾评工作的日程安排。最后,对灾评工作中存在的问题,如烈度评定、生命线宏观损失、抗震设防目标、人员死亡分布等进行了探讨,并给出了几点想法和认识。     

Ground-motion intensity measure correlations observed in Italian strong-motion records

Ground-motion models (GMMs) are widely used in probabilistic seismic hazard analysis (PSHA) to estimate the probability distributions of earthquake-induced ground-motion intensity measures (IMs) at a site, given an earthquake of a certain magnitude occurring at a nearby location. Accounting for spatial and cross-IM correlations in earthquake-induced ground motions has important implications on probabilistic seismic hazard and loss estimates. This study first develops a new Italian GMM with spatial correlation for 31 amplitude-related IMs, including peak ground acceleration (PGA), peak ground velocity (PGV), and 5%-damped elastic pseudo-spectral accelerations (PSAs) at 29 periods ranging from 0.01 to 4 seconds. The model estimation is performed through a recently developed one-stage nonlinear regression algorithm proposed by the authors, known as the Scoring estimation approach. In fact, current state-of-practice approaches estimate spatial correlation separately from the GMM estimation, resulting in inconsistent and statistically inefficient estimators of interevent and intraevent variances and parameters in the spatial correlation model. We test whether this affects the subsequent cross-IM correlation analysis. To this aim, based on the newly developed GMM, the empirical correlation coefficients from interevent and intraevent residuals are investigated. Finally, a set of analytical correlation models between the selected IMs are proposed. This is of special interest as several correlation models between different IMs have been calibrated and validated based on advanced GMMs and global datasets, lacking earthquakes in extensional regions; however, modeling the correlation between different IM types has not been adequately addressed by current, state-of-the-art GMMs and recent ground-motion records for Italy.     

地震灾害损失评估的新方法--航空测量法

地震灾害损失评估是一项非常讲究速度和准确性的工作.文章简要介绍了目前国际上正在兴起的一种新的地震灾害损失评估方法--航空测量法及其基本原理和主要的技术环节,供有关管理者和技术人员参考.     

利用遥感图像数据基于模板匹配的震毁灾损研究

有效评估震灾损失可及时、可靠地了解地震灾区实时情况,提高破坏性地震下人们的反应能力,满足应急指挥需求。为提高震灾损失评估精度,对所获取遥感图像进行滤波及局部灰度调整处理,提出基于遥感图像模板匹配的震毁灾损研究。首先获取震区的遥感影像,考虑所获取图像与模板图像的偏移状况对图像进行模板匹配,提取与模板匹配后特征区域的特征值,获取空间网格点上的成像值,依据成像点自动评估震灾损失,其中能量最大的点即为震害受损最严重的位置,对图像所有内廓像素点结果进行遍历,确定提取地震灾区整体的受损特征结果。仿真实验发现,所提方法可提取出震灾损失状况,初步为地震灾害损失评估提供参考借鉴,但仍需要进一步研究,以提高方法的普遍适用性。     

教育系统和卫生系统地震灾害损失评估方法

历次地震灾害调查发现,中小学校舍和乡镇卫生院(所)房屋震害较重,教学设施、设备和医疗防疫器材损失严重。结合地震现场工作实际,在现行地震灾害损失评估方法的基础上探讨了教育系统和卫生系统的地震灾害调查和经济损失评估方法。     

A Probabilistic Displacement-based Vulnerability Assessment Procedure for Earthquake Loss Estimation

Earthquake loss estimation studies require predictions to be made of the proportion of a building class falling within discrete damage bands from a specified earthquake demand. These predictions should be made using methods that incorporate both computational efficiency and accuracy such that studies on regional or national levels can be effectively carried out, even when the triggering of multiple earthquake scenarios, as opposed to the use of probabilistic hazard maps and uniform hazard spectra, is employed to realistically assess seismic demand and its consequences on the built environment. Earthquake actions should be represented by a parameter that shows good correlation to damage and that accounts for the relationship between the frequency content of the ground motion and the fundamental period of the building; hence recent proposals to use displacement response spectra. A rational method is proposed herein that defines the capacity of a building class by relating its deformation potential to its fundamental period of vibration at different limit states and comparing this with a displacement response spectrum. The uncertainty in the geometrical, material and limit state properties of a building class is considered and the first-order reliability method, FORM, is used to produce an approximate joint probability density function (JPDF) of displacement capacity and period. The JPDF of capacity may be used in conjunction with the lognormal cumulative distribution function of demand in the classical reliability formula to calculate the probability of failing a given limit state. Vulnerability curves may be produced which, although not directly used in the methodology, serve to illustrate the conceptual soundness of the method and make comparisons with other methods.     

基于大数据的地震损失价值评估模型设计

破坏性地震往往导致严重的经济损失及人员伤亡,对地震损失价值评价有助于震前找出抗震弱点,提高抗震能力,实现减轻地震灾害损失的目的。传统空间模型在地震数据处理过程中,无法处理大数据对空间尺度选择的干扰,存在地震损失评估结果偏差大以及波动性高的弊端。因此,在云计算平台下,提出基于大数据的地震损失价值评估模型设计,对模型HAZ-China大数据的服务层次、地震应用服务层以及HAZ-China大数据体系结构进行设计,为用户提供震前、震时以及震后的地震损失价值评估服务。模型采用HBase分布式数据库实现大数据的存储和分析,设计房屋震害数据库以及云计算模型,通过考虑大数据因素的地震灾害损失综合评估过程,实现地震损失价值的准确评估。实验结果说明,所设计模型可实现地震损失价值的准确评估,具有较高的评估精度和稳定性。     

ShakeMap在2014年于田7.3级地震快速损失评估中的应用

本文介绍了2014年2月12日新疆于田Ms7.3级地震的震害特征,将改进的ShakeMap烈度图成功地运用到了于田7.3级地震的快速损失评估中.结果表明,考虑了场地效应的ShakeMap烈度图明显优于当前“十五”应急指挥系统的衰减关系模型的烈度图,能更好地为地震灾害损失评估服务,其快速评估的结果更接近官方公布的数据.因此,应用ShakeMap技术在震害损失快速评估中,能显著地提高评估结果的准确性.     

A predictive model for Arias intensity at multiple sites and consideration of spatial correlations

Arias intensity, I_a, has been identified as an efficient intensity measure for the estimation of earthquake‐induced losses. In this paper, a new model for the prediction of Arias intensity, which incorporates nonlinear site response through the use of the average shear‐wave velocity and a heteroskedastic variance structure, is proposed. In order to estimate the effects of ground motions on spatially‐distributed systems, it is important to take into account the spatial correlation of the intensity measure. However, existing loss‐estimation models, which use I_a as an input, do not take this aspect of the ground motion into account. Therefore, the potential to model the spatial correlation of Arias intensity is also investigated. The empirical predictive model is developed using recordings from the Pacific Earthquake Engineering Research Center Next Generation of Attenuation database whereas the model for spatial correlation makes use of the well‐recorded events from this database, that is the Northridge and Chi‐Chi earthquakes. Copyright © 2011 John Wiley & Sons, Ltd.     

地震指数保险在云南漾濞6.4级地震中的作用及启示

指数保险具有触发参数客观、理赔反应迅速的特点,是政策性保险的优先选择。云南省作为地震灾害频发且损失严重地区,率先开展了地震指数保险的试点工作。2021年5月21日,云南省漾濞县发生6.4级地震,触发了地震指数保险赔付。本文对地震指数保险赔偿原则及其在云南试点地区的实施情况等进行介绍,根据漾濞地震损失和赔付情况,总结地震指数保险实施优势和存在的问题,并对地震保险在我国的发展进行展望。     

地震经济损失评估之装修破坏损失比厘定研究

随着经济的发展,建筑装修损失占地震总损失的比重越来越大,对于大中城市装修损失的评估越来越引起人们的重视,而损失比是地震经济损失评估中非常关键的参数。本文在对损失比的概念及其国内外研究现状综合分析的基础上,采用现场抽样与专家咨询(Delphi法)相结合的方法,通过加权统计给出了不同结构类型、不同使用功能的建筑装修震害损失比取值范围。最后,将本文给出的取值范围与其它文献取值进行了对比分析,结果表明:在相同破坏等级下,装修破坏损失比要高于主体结构损失比,且在中等破坏及以上破坏等级下,前者要远大于后者。     

四川汶川8.0级地震损失评估

本文简要介绍了2008年5月12日汶川8.0级直接震害损失评估方法和结果,分析了震害损失特点和经验教训。评估得到此次地震直接经济损失为为6920.11亿元,占2007年全国国内生产总值(GDP)的2.81%。本文基于中国地震局地震现场应急工作队的损失评估报告,反映数百人工作的成果。     

天津市面向震害快速评估的房屋和人口空间化研究*

以天津市的大比例尺房屋空间数据和第六次人口普查数据为基础,利用GIS空间分析功能,模拟了天津市房屋和人口空间分布,产出1km格网的房屋数据和分时段人口公里格网数据。经检验,模拟的房屋和人口数据达到了较高精度,能够较准确地表达行政单元内部的房屋和人口空间分布。将模拟结果应用到设定地震震害评估中,与基于平均密度法的评估结果对比,表明基于公里格网评估的结果更为合理,减少了由于房屋和人口分布不均匀造成的误差,能够为地震应急工作提供可靠的数据支撑。     

Vulnerability Analysis in Earthquake Loss Estimate

The adobes in Costa Rica have almost the same vulnerability as the old civil houses in China, which represent vulnerability in the worst case. On the other hand, the high quality buildings in Costa Rica have the same vulnerability as the reinforced concrete buildings in China due to the adoption of state-of-art techniques in design and construction, which represent the vulnerability of the best case. The macroeconomic vulnerability defined by Chen et al. falls in the middle of the two extreme cases of the inventory studied because the total macroscopic loss is the sum of losses of different types of buildings and facilities. Therefore the macroeconomic vulnerability must be greater than that of the best case and less than that of the worst. The use of macroscopic vulnerability in earthquake loss estimate is easy, simple and feasible. The vulnerability plots are preliminary in nature and should be refined with additional earthquake loss data.     

地震损失预测评估中的易损性分析

代表着地震易损性中最坏情形的哥斯达黎加土坯房和中国老旧民房有着几乎相同的易损性,而表示地震易损性中最好情形的哥斯达黎加高质量楼房和中国钢筋混泥土结构楼房,由于采用了现代设计和建筑技术,也有着相同的易损性。陈Ｙｏｎｇ等提出的宏观经济易损性位于常规易损性分类清单中的这两种极端情况之间,因为宏观经济损失是各种建筑设施损失的总和,故宏观经济易损性差于最好的建筑情况,而优于最坏的情况。采用宏观经济易损性的地     

Correlation properties of integral ground-motion intensity measures from Italian strong-motion records

This study investigates the correlation properties of integral ground-motion intensity measures (IMs) from Italian strong-motion records. The considered integral IMs include 5–95% significant duration, Housner intensity, cumulative absolute velocity, and Arias intensity. Both IM spatial correlation and the correlation between different integral and amplitude-based IMs (i.e., cross-IM correlation) are addressed in this study. To this aim, a new Italian ground-motion model (GMM) with spatial correlation for integral IMs is first introduced. Based on the newly developed GMM, the empirical correlation coefficients from interevent and intraevent residuals are investigated and various analytical correlation models between integral IMs and amplitude-based IMs are proposed. The effective range parameter representing spatial correlation properties and the trend in the cross-IM correlations are compared with existing models in the literature. The variability of the effective range parameters with respect to event-specific features is also discussed. Modeling ground-motion spatial and cross-IM correlations is an important step in seismic hazard and risk assessment of spatially distributed systems. Investigating region-specific correlation properties based on Italian strong-motion records is of special interest as several correlation models have been developed based on global datasets, often lacking earthquakes in extensional regions such as Italy.