The Disruption Index (DI) as a tool to measure disaster mitigation strategies

Apart from the loss of lives, injuries and homeless resulting from an earthquake, not only the economy and physical landscape are altered, but also the lives of citizens and their places of work are dramatically altered. If critical services and functions are disrupted for more than a reasonable time period, consequences can be severe. All communities are at risk and face potential disaster, if unprepared. The Disruption Index (DI) is a tool that allows the representation of a complex and multidimensional situation in a concise and easier way, providing institutions and communities with a way to identify the global earthquake impact in a geographical area, the elements at risk, and the means to reduce it. In the present paper, after a short review of the concept of DI, its geographic (spatial) distribution is developed and an application to some cities in Algarve (Portugal) is made. Then, the use of DI in the context of measuring the risk reduction for alternative disaster mitigation strategies is introduced and illustrations are presented.     

基于改进的风险矩阵法的生命线网络地震脆弱性分析

生命线网络的脆弱性不单单只表示地震发生后对网络作用而产生的后果,还应该包括网络的连通情况。本文在重新确定生命线网络脆弱性定义的基础上,运用风险评估理论中的风险矩阵方法综合考虑生命线网络的连通性能和失效后果两个方面来评价生命线网络的脆弱性,并以一个供气管网为例说明改进的风险矩阵法评价生命线网络脆弱性的有效性和合理性,找出供气管网中脆弱性等级最高的节点,分析其脆弱性等级最高的原因,以便于重点保护,并降低网络的脆弱性。     

Evaluation of local site effect from microtremor measurements in Babol City,Iran

Every year, numerous casualties and a large deal of financial losses are incurred due to earthquake events. The losses incurred by an earthquake vary depending on local site effect. Therefore, in order to conquer drastic effects of an earthquake, one should evaluate urban districts in terms of the local site effect. One of the methods for evaluating the local site effect is microtremor measurement and analysis. Aiming at evaluation of local site effect across the city of Babol, the study area was gridded and microtremor measurements were performed with an appropriate distribution. The acquired data was analyzed through the horizontal-to-vertical noise ratio (HVNR) method, and fundamental frequency and associated amplitude of the H/V peak were obtained. The results indicate that fundamental frequency of the study area is generally lower than 1.25 Hz, which is acceptably in agreement with the findings of previous studies. Also, in order to constrain and validate the seismostratigraphic model obtained with this method, the results were compared with geotechnical, geological, and seismic data. Comparing the results of different methods, it was observed that the presented geophysical method can successfully determine the values of fundamental frequency across the study area as well as local site effect. Using the data obtained from the analysis of microtremor, a microzonation map of fundamental frequency across the city of Babol was prepared. This map has numerous applications in designing high-rise building and urban development plans.     

城市地震预警误报的社会影响与措施研究

通过对国内外有关地震预警、震时人们心理和行为的文献和试验研究成果的综合分析,结合我国的实际情况,当城市地震预警系统出现误报后,对于社会可能产生的负面影响和潜在的积极影响进行了讨论,并提出相应的措施以减小误报可能产生的负面影响。     

面向防震减灾的人口数据空间化研究——以2007年宁洱地震灾区为例

入口是地震灾害的重要受灾体,准确的入口空问分布信息是防震减灾工作的重要依据.本文借助地理信息系统,将人口统计数据与高分辨率遥感数据相结合,应用基于居民地的人口数据空间化方法,模拟人口空间分布.首先根据城市人口—面积异速生长模型的分形几何意义,推导出城乡人口一面积统一模型;进而以2007年宁洱地震灾区为例,在建立居民地分类体系和遥感解译标志的基础上,目视解译获得准确的居民地信息;最后应用城乡人口—面积统一模型获得网格人口密度矢量数据.经检验,本文的结果达到了较高的精度.同时在人口数据空间化完成的基础上,以地震受灾人口估算为例,探讨了人口数据空间化在防震减灾中的应用.研究结果表明,基于网格人口矢量数据的受灾人口估算结果更能客观反映地震灾情,可以为防震减灾和应急救援工作提供可靠的依据.     

A unified framework for earthquake risk assessment of transportation networks and gross regional product

Natural threats like earthquakes, hurricanes or tsunamis have had serious impacts on communities. In the past, major earthquakes in the United States like Loma Prieta 1989, Northridge 1994, or recent events in Italy like L’Aquila 2009 or Emilia 2012 emphasized the importance of preparedness and awareness to reduce social impacts. In addition to that, earthquake damaged businesses dramatically reduced the gross regional product. Generating scenario earthquakes in a proper way is important to suitably assess the risk in bridge networks and social losses in terms of gross regional product reduction. Seismic hazard is traditionally assessed by means of probabilistic seismic hazard analysis (PSHA). Although PSHA well represents the hazard at a specific location it is not suitable for spatially distributed systems. Scenario earthquakes can overcome this problem; they represent the actual distribution of ground shaking for a spatially distributed system while being hazard consistent. In this work a methodology to generate scenario earthquakes has been proposed using a novel approach with the aim of being the basic step for investigating possible earthquake consequences in seismic areas and contributing to reduce losses.     

地震灾害评估和灾害数据管理系统(EDMS)的开发——以丽江地震为例(英文)

地震一旦发生,给出一个快速而合理的震害评估,对于减轻地震灾害和灾区重建具有极其重要的意义。最近几年,大量的研究工作试图在GIS平台上建立一个这样的系统以改善和加快震害评估的速度,有的已经得到了实际应用。然而,几乎所有这些研究和开发都是基于城市地区,特别是发达国家的城市地区。而对于发展中国家的乡村地区,由于不具备象发达城市地区那样的基础数据和基础设施,很难把适用于发达的城市地区的类似系统移植过来。此外,尽管同样强度的地震在发达的城市地区造成的损失远大于发展中国家的乡村地区,但地震灾害在乡村地区所造成的损失恢复起来要比在发达的城市地区困难得多。所以,有必要在GIS平台上建立一个适用于乡村地区,特别是发展中国家乡村地区的灾害评估和灾害数据管理系统。本研究的目的就是在GIS平台上建立一个适用于中国西南偏远乡村地区的地震灾害评估和灾害数据管理系统(EDMS)。建立本系统的依据是中国地震局1988年编的《地震现场工作大纲和技术指南》中的“现场地震灾害损失评估方法”。本系统由1)震后快速评估与2)震害数据管理和综合评估2部分组成。选择的范例研究区为丽江地区,使用的基础数据包括云南省特别是丽江专署和丽江县的家庭和人口分布、各     

广东揭汕潮地区城市群地震灾害及地震易损性分析

从历史最大地震烈度分布图分析,可知揭阳、汕头、潮州三市位于Ⅶ～Ⅷ度高地震烈度区。该城市群地震灾害有以下特点:市区发生破坏性地震的潜在危险性大;地震时市区地震烈度高,地震灾害大,损失严重。采用宏观经济易损性的地震损失分析方法,重演该区的历史破坏性地震。分析表明:抓好该区的防震减灾工作是保持社会和经济建设持续发展的一项重要工作。     

考虑震害因子耦合作用的砌体建筑群破坏概率模型研究

砌体建筑群在地震中往往破坏严重损失巨大,合理评估地震作用对不同种类砌体结构造成破坏的风险变得至关重要。传统基于后验概率的地震危险性分析方法忽略了砌体建筑个体差异性的影响,未深入考虑多种震害因子的耦合作用。本文以华南地区砌体建筑群为例,开发了一种集成概率方法来对城市砌体结构的破坏风险进行建模,考虑建筑年代、层数、使用用途和墙厚四类震害因子的耦合影响,采用(Kolmogorov-Smirnov)K-S检验,在设定地震动参数下选取Gaussian分布、Log-Normal分布、Gumbel分布和Beta分布四种概率分布对该地区砌体建筑物的破坏状态概率分布参数进行拟合。通过均方根误差(Root Mean Square Error)RMSE进行拟合优度评价,最终建立基于Gaussian分布和Log-Normal分布的砌体建筑物破坏联合概率模型。最后,以华南地区三个城市典型砌体建筑物为例进行实例对比验证,将基于本文建立的建筑破坏概率模型推算出的砌体建筑群震害矩阵与基于单体结构分析得到的震害矩阵进行对比,与理论值最大偏差为0.033 3。研究表明：本文构建的集成概率方法能够获得更加合理的城市砌体建筑...     

The role of the urban system dysfunction in the assessment of seismic risk in the Mt. Etna area (Italy)

A procedure for seismic risk assessment is applied to the Mt. Etna area (eastern Sicily, Italy) through assessment of urban system dysfunction following the occurrence of an earthquake. The tool used is based on the Disruption Index as a concept implemented in Simulator QuakeIST, which defines urban disruption following a natural disaster. The first element of the procedure is the definition of the seismic input, which is based on information about historical seismicity and seismogenic faults. The second element is computation of seismic impact on the building stock and infrastructure in the area considered. Information on urban-scale vulnerability was collected and a geographic information system was used to organise the data relating to buildings and network systems (e.g., building stock, schools, strategic structures, lifelines). The central idea underlying the definition of the Disruption Index is identification and evaluation of the impact on a target community through the physical elements that most contribute to severe disruption. The procedure applied in this study (i.e., software and data) constitutes a very useful operational tool to drive the development of strategies to minimise risks from earthquakes.     

基于ArcView9.0的城市震害预测及应急对策信息系统研究

介绍了城市防震减灾信息系统基本的构成及功能,并针对国内研发中存在的不足从四个方面进行了完善,即增加了地震预警级别判定功能,丰富了地震信息的录入方式,改进了城市群体建筑物震害预测的计算模型,引入了应急对策模块并利用G IS的可视化功能加以表现。在此基础上研发了基于ArcV iew9.0的城市震害预测及应急对策信息系统,并以山西运城市城区的实际数据进行了系统演示。     

城镇地震应急快速评估系统研究

随着城镇化水平的快速提高,地震灾害高风险区域城镇数量不断增加,城镇人口密度增大,加剧了城镇地震灾害的风险。然而县市防震减灾工作部门大多对城镇地震应急的科技支撑能力薄弱,如缺乏专门的技术平台及时对地震灾情进行有效的评估等,影响了当地地震应急的成效。本文针对县市防震减灾工作部门在城镇地震应急快速评估工作中存在的问题,以国家可持续发展实验区丹棱县为例,设计并构建了城镇地震应急快速评估系统,为城镇地震应急快速评估提供了技术平台,可提升县市防震减灾工作部门的地震应急工作科技含量和管理服务能力。     

宁夏地震灾情捕获系统设计与实现

破坏性地震发生后,各级政府、各级指挥部需要第一时间获取到地震现场及周边的灾情信息,包括灾情图片、图像。宁夏地震局立足于本区重点危险区、人口密集区、重要设施分布点、次生灾害多发区,利用现有超短波、3G通信链路,在宁夏境内建立基于P头触发、自动拍摄、自动上传、自动存储、自动分发的灾情捕获系统,解决震后对震区及周边灾情图像及时获取的需要,为震后指挥决策提供依据。     

熵的原理与地震活动研究

熵是多种学科的一个重要交叉点。熵的原理广泛适用于物理、化学、生物、医学、气象乃至社会经济等科学领域,并已取得了令人注目的成果。本文以熵的基本含意出发,简要地阐述了熵概念的扩展,包括热温熵、信息熵以及条件熵等。将地震孕育过程作为一个复杂的开放系统,基于耗散结构理论的基本思想,为定量描述地震活动时、空、强分布的有序度,引入地震活动熵作为序参量,并将其应用于大地震前后地震活动演变特征的研究。初步结果表明,随着临近大地震的发生,在一定范围内地震活动熵值减小,即地震活动分布状态从无序趋向有序。可以预期,把熵的原理引入地震研究领域必将加深人们对地震发生物理过程本质的认识。同时也将为探索地震预测提供新的思路和新的途径。     

Seismic microzonation of Chania,Crete (Greece) based on SASW measurements and non-linear site response analyses

Following a brief overview of past applications of, and more recent advances on seismic microzonation, the results of a seismic microzonation study for the city of Chania, Greece, are presented. The study was based on V_s vs. depth profiles obtained at 19 sites of the urban area by performing SASW measurements. The spatial distribution of V_s values was utilized in estimating V_s30 values, depth to bedrock and the fundamental ground period variation across the area of the city as well as for conducting 1-D finite element non-linear inelastic site response analyses. The input earthquake excitations employed in the response analyses were based on the results of an available seismic hazard study for the Chania Area. The results of analyses were utilized for establishing the spatial distribution of rock motion amplification, the expected ground motions and spectral values in the area of the city. Contour maps providing values of the expected ground motion in the urban area are given which may become a practical tool in assessing the seismic risk and expected damage in the Chania area. The maps can also be used in the design of new earthquake resistant structures or the seismic retrofitting of existing ones. Finally, the results were utilized to demonstrate the inadequacy of using V_s,30 values for classifying the soil conditions in the Chania area.     

Current state of integrated earthquake simulation for earthquake hazard and disaster

This paper presents the current state of integrated simulation for earthquake hazard and disaster. This simulation takes advantage of the macro–micro analysis method; this method estimates an earthquake’s strong motion with high spatial and temporal resolution, using the bounding medium theory to obtain optimistic and pessimistic estimates of expected strong motion distribution and the singular perturbation expansion that results in an efficient multi-scale analysis. Integrated earthquake simulation calculates seismic responses for all structures in a target area, inputting simulated strong ground motion to a structure analysis method that is plugged into the system by means of a wrapper; a suitable method, linear or nonlinear, is chosen depending on the type of the structure. The results of all simulations are visualized so that residences and government officials can share a common recognition of earthquake hazard and disaster. Two examples of this integrated earthquake simulations are presented; one is made by plugging nonlinear structure analysis methods into the system, and the other is made for an actual city, the computer model of which is constructed with the help of available geographical information systems.     

Online location of seismic damage to a water distribution system

As one of the most important urban lifeline systems, a water distribution system can be damaged under a strong earthquake, and the damage cannot easily be located, especially immediately after the event. This often causes tremendous difficulties to post-earthquake emergency response and recovery activities. This paper proposes a methodology to locate seismic damage to a water distribution system by monitoring watcr head online at some nodes in the water distribution system. An artificial neural network-based inverse analysis method is developed to estimate the water head variations at all nodes that are not monitored based on the water head variations at the nodes that are monitored. The methodology provides a quick, effective, and practical way to locate seismic damage to a water distribution system.     

华北大震序列的断裂系模式及破裂过程的联合反演

本文从断裂系扩展的角度,研究了华北邢台、渤海、海城和唐山地震序列的发生过程.通过对前震-主震-余震地震活动图象的剖析,我们发现,这些地震序列是由不同长度、不同几何分布的相关断裂系相互作用和扩展的结果.根据地震活动图象和断裂扩展理论,对每个地震序列提出了相应的断裂系模式,并用断裂有限单元法将震源机制、地震活动图象的分期变化和大地形变等观测资料相结合,进行联合反演,再次对断裂系模式的几何和力学参数进行了修正,从而得到各个地震序列破裂过程的最佳结果.同时我们还发现,一个走滑大地震序列临近结束时,地震活动图象的总体轮廓呈现Z形.这是由于断裂系内的拐折扩展分支相互作用和连通成为一体的结果,这种总体Z形的出现,可作为地震序列结束的标志.      

中国大陆地震灾害时空分布特征及地形影响因素分析

基于1990—2020年地震灾害损失(包括经济损失、人员死亡和人员受伤)数据,分析了过去30年中国大陆地区地震灾害损失的时空分布特征。采用常规标准化方法分析了1990—2019年我国大陆地区地震灾害经济损失的时间分布,认为地震灾害在过去30年间逐渐由人身安全威胁向经济财产威胁转变。通过整理分析2011—2020年各省地震灾害的空间分布特征,认为有必要进一步强化四川、云南、甘肃的抗震设防工作,提升其抵御灾害地震风险的能力;在中东部经济较发达地区,应尤其关注地震造成的间接经济损失和人员受伤情况。通过各省的提取地形坡度因素,采用地统计方法定量计算地震损失与地形坡度因素间的空间相关性系数,认为在以自然条件为基础分析地震灾害的过程中,因震致死与地形的空间相关性不如经济损失和因震致伤高,结合过去30年地震灾害的时间分布特征,得出因震致死和因震致伤总体保持平稳,但经济损失急剧增长,且增长趋势越来越显著,这主要是由经济发展等社会人文因素导致。