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.     

Development of a geotechnical and geophysical database for seismic zonation of the Ankara Basin,Turkey

Engineering geological and geotechnical site characteristics were assessed and seismic hazard studies performed for the Upper Pliocene to Pleistocene fluvial and Quaternary alluvial and terrace deposits for a site west of Ankara, Turkey. Sediment conditions were determined and a soil profile was characterized by surface geophysical methods. These studies were integrated with existing in-situ characterization studies to create a seismic and geotechnical database for the site. A seismic zonation map of the site was then prepared. Site classification systems were assigned to account for site effects in relation to seismic hazard assessments. The consequences of the seismic hazards were investigated and recommendations were presented.     

Seismic risk assessment of buildings in urban areas: a case study for Denizli,Turkey

This study aims to carry out a seismic risk assessment for a typical mid-size city based on building inventory from a field study. Contributions were made to existing loss estimation methods for buildings. In particular, a procedure was introduced to estimate the seismic quality of buildings using a scoring scheme for the effective parameters in seismic behavior. Denizli, a typical mid-size city in Turkey, was used as a case study. The building inventory was conducted by trained observers in a selected region of Denizli that had the potential to be damaged from expected future earthquakes according to geological and geotechnical studies. Parameters that are known to have some effect on the seismic performance of the buildings during past earthquakes were collected during the inventory studies. The inventory includes data of about 3,466 buildings on 4,226 parcels. The evaluation of inventory data provided information about the distribution of building stock according to structural system, construction year, and vertical and plan irregularities. The inventory data and the proposed procedure were used to assess the building damage, and to determine casualty and shelter needs during the M6.3 and 7.0 scenario earthquakes, representing the most probable and maximum earthquakes in Denizli, respectively. The damage assessment and loss studies showed that significant casualties and economic losses can be expected in future earthquakes. Seismic risk assessment of reinforced concrete buildings also revealed the priorities among building groups. The vulnerability in decreasing order is: (1) buildings with 6 or more stories, (2) pre-1975 constructed buildings, and (3) buildings with 3–5 stories. The future studies for evaluating and reducing seismic risk for buildings should follow this priority order. All data of inventory, damage, and loss estimates were assembled in a Geographical Information System (GIS) database.     

Earthquake disaster risk index for Canadian cities using Bayesian belief networks

Devastation observed from global earthquakes highlights the need for a decision-making tool to aid in prioritisation and resource allocation for seismic risk management. In this paper, a seismic risk index assessment tool is developed using Bayesian belief network (BBN) that considers geological, engineering, economic, social, political and cultural factors. Previously proposed hierarchical structure is modified and modelled using a BBN. The subjective probabilities of the BBN are derived using expert knowledge. Furthermore, to illustrate versatility of the proposed model, a case study is undertaken for 11 Canadian cities.     

Earthquake risk and its mitigation in Istanbul

Physical and societal vulnerability to earthquakes and expected physical, social, economic, and industrial losses in Istanbul are outlined. This risk quantification has served as the basis for the Earthquake Masterplan. Risk-mitigation activity that was, and is, being conducted by several agencies and in different context and sectors are elaborated.     

洪涝灾害风险评估与分区研究进展

在全球气候变化和城市化进程不断加快的背景下,城市洪涝灾害频发,造成严重的经济损失和人员伤亡问题。对近年来中国典型城市洪涝灾害进行系统整理介绍,说明洪涝灾害带来的人员伤亡和经济损失巨大。风险评估作为一种非工程性防洪措施,是城市洪涝风险管理的首要工作,精确、高效的把握洪灾过程等特征可以为防灾减灾工作提供科学依据。对城市洪涝风险评估与分区的概念和内容进行系统梳理,常用的风险评估方法有数理统计法、不确定性分析法、遥感影像评估法、指标体系评估法、情景模拟评估法；风险分区常用方法有阈值法、经验公式法和物理机制法。论述了城市洪涝风险评估与分区常用方法的应用范围、优缺点及其发展前景。     

An integrated earthquake damage assessment methodology and its application for two districts in Istanbul, Turkey

This paper presents an integrated, earthquake-damage assessment that standardizes and quantifies methods of analysis. The proposed methodology evaluates all damage-causing phenomena, both individually and in combination. This approach inherently relates to soil-structure interactions by quantifying site-specific geotechnical and structural properties. Specifically considered is ground shaking, the primary damage-causing phenomenon. Also evaluated are the collateral effects of liquefaction, degradation of seismic-bearing capacity and slope failure (landslides). The methodology incorporates a literature-derived probabilistic assessment of damage-causation, and is interpreted and presented as single numbers deemed “Damage Grades.” These damage grades integrate the initial probabilistic evaluation with professional experience and judgment in order to determine potential damage to a particular structure at a particular location. This methodology was applied, with success, to two different locations in Istanbul, Turkey. It should be tested by engineering geologists and geotechnical engineers, for it may be applicable to earthquake-prone areas elsewhere.     

Modeling of seismic hazard for Turkey using the recent neotectonic data

Recent developments in the neotectonic framework of Turkey introduced new tectonic elements necessitating the reconstruction of Turkey's seismic hazard map. In this regard, 14 seismic source zones were delineated. Maximum earthquake magnitudes for each seismic zones were determined using the fault rupture length approximation. Regression coefficients of the earthquake magnitude–frequency relationships for the seismic zones were compiled mostly from earlier works. Along with these data, a strong ground motion attenuation relationship developed by Joyner and Boore [Joyner, W.B., Boore, D.M., 1988. Measurement, characterization, and prediction of strong ground motion. Earthquake Engineering and Soil Dynamics, 2. Recent Advances Ground Motion Evaluation, pp. 43–102.] was utilized to model the seismic hazard for Turkey using the probabilistic approach. For the modeling, the “earthquake location uncertainty” concept was employed. A grid of 5106 points with 0.2° intervals was constituted for the area encompassed by the 25–46°E longitudes and 35–43°N latitudes. For the return periods of 100 and 475 years, the peak horizontal ground acceleration (pga) in bedrock was computed for each grid point. Isoacceleration maps for the return periods of 100 and 475 years were constructed by contouring the pga values at each node.     

城市化防震减灾经济性研究

本文通过对东南沿海地震背景和地震破坏性经济损失,结合国内外城市化进程中防震减灾经济性对比研究,认为地震破坏的负面效应所带来的经济损失十分巨大。因而必须加强防震减灾工作为保障城市化顺利发展服务。     

Integrated seismic hazard evaluation and disaster management approach for Turkey

A significant proportion of the urban areas in Turkey is subject to high seismic risk. An important step for seismic risk mitigation is to define the hazard and damage after an earthquake. This paper proposes an integrated seismic hazard assessment and disaster management processes for Turkey. The proposed methodology utilizes information technologies in its seismic assessment component that provides fast results for assessment. First, image process methodology by using satellite images was implemented in the seismic assessment process for fast evaluation right after an earthquake. Second, the seismic assessment process was integrated with disaster management process. As a result, through integrated seismic hazard evaluation and disaster management procedure, an effective, fast and dependable estimation of loss for Turkey was planned.     

上海地区地质灾害危险性评估关键技术问题研究

"建设项目地质灾害危险性评估技术规程"即将成为上海市工程建设规范。该规程总结了以往评估实践,细化和完善了具体技术细则,强化了指导性和可操作性。介绍了上海地区确定的地面沉降、地基变形、边坡失稳、砂土液化、水土突涌、岸带冲淤、浅层天然气害、水土污染等8个评估灾种的界定、地质环境条件复杂程度的分类要素及划分标准、建设项目重要性的具体划分、评估范围的确定、地质灾害危险性分级分区原则、拟建场地建设适宜性评价准则等灾评实践及规程编制中的关键技术问题。     

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.     

城市地面塌陷灾害风险评估研究

随着城市化进程不断加快,城市地下空间安全问题引起广泛关注。本文以影响地下空间安全的典型灾害-地面塌陷为例,开展可能性风险评估研究,为降低地面塌陷灾害损失提供理论支撑。城市地面塌陷成因复杂,为了保证评价过程和结果的客观全面,通过调研对塌陷引发因素进行了总结,从管道因素、病害体因素、环境因素三个方面建立风险发生可能性评价指标体系,并使用AHP-熵权法-灰色关联法组合评价,建立地面塌陷风险评价模型。将该模型应用于郑州市典型地下空洞工程案例进行评估分析,结果表明:地面塌陷风险评价结果与实测结果相符,证明了评估模型的科学性,同时为城市地面塌陷预防提供了决策参考。     

福建省防震减灾与可持续发展研究

本文从本区独特的地震地质背景、地震活动与断裂构造关系出发,论述地震破坏对经济发展的影响,说明只有加强防震减灾体系建设,方可保障社会与经济可持续发展。     

基于模糊数学法评价滇西保山地区麻榔河泥石流沟的危险性

通过野外实地调查云南省保山市怒江东岸麻榔河泥石流的发育特征,并对其洪积物进行光释光（OSL）测年,认为是一个年轻的泥石流沟,危险性较大。在此基础上,依据泥石流发生的影响因素具有复杂性和模糊性的特点,采用模糊数学法对其危险性进行综合评判。选取7个因子作为泥石流危险度评价的主要关联因子,评价结果与野外调查的实际情况相符,属于中度危险（Ⅲ）。同时指出了评价过程中的2个关键点：建立权重集和确定隶属度。建立权重集的方法采用＂理想点＂的距离之和极小化为目标来优化确定,隶属度利用半梯形分布模型原理设计隶属函数来实现。经过反复的实验计算,证实此方法可操作性强,结果更符合实际。     

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。     

新疆冰雹灾害经济损失评估及风险区划研究

基于1984-2014年新疆雹灾受灾面积、总成灾面积、农作物播种面积、新疆生产总值及以县为单位的雹灾频次等统计数据,构建雹灾经济损失指标和风险度指标,进行新疆冰雹灾害评估研究。其中雹灾经济损失指标可用于评价新疆雹灾经济损失的趋势变化,风险度指标可借助GIS空间信息处理技术形成新疆雹灾风险区划。研究表明：雹灾经济损失总体呈波动上升趋势,且受环境不稳定度的影响较大,二者保持着较好的正相关性。新疆冰雹灾害总体以中、低度风险为主,高风险次之。高风险区主要集中在喇叭形河谷地带的伊犁地区及其两侧的阿克苏、博州等地,建议通过调整农业产业结构、提升人工防雹能力等方式降低上述区域的雹灾损失。     

Earthquake Disaster Management and Insurance

As one of the most powerful tools to reduce the earthquake loss, the Earthquake Disaster Management [EDM] and Insurance [EI] have been highlighted and have had a great progress in many countries in recent years. Earthquake disaster management includes a series of contents, such as earthquake hazard and risk analysis, vulnerability analysis of building and infrastructure, earthquake aware training, and building the emergency response system. EI, which has been included in EDM after this practice has been done for many years, include these contents: insurance model, financing. This paper presents the development of china in EDM and EI. The main contents include: (1) the statue and trend of earthquake disaster management and insurance in china; (2) the progresses and new methods about the seismic risk zonation and vulnerability analysis, and the future developing trend, the application of GIS in earthquake disaster assessment is introduced; (3) the way and illustration in building the earthquake disaster e     

基于模糊数学法评价滇西保山地区麻榔河 泥石流沟的危险性

通过野外实地调查云南省保山市怒江东岸麻榔河泥石流的发育特征,并对其洪积物进行光释光（OSL）测年,认为是一个年轻的泥石流沟,危险性较大。在此基础上,依据泥石流发生的影响因素具有复杂性和模糊性的特点,采用模糊数学法对其危险性进行综合评判。选取7个因子作为泥石流危险度评价的主要关联因子,评价结果与野外调查的实际情况相符,属于中度危险（Ⅲ）。同时指出了评价过程中的2个关键点:建立权重集和确定隶属度。建立权重集的方法采用“理想点”的距离之和极小化为目标来优化确定,隶属度利用半梯形分布模型原理设计隶属函数来实现。经过反复的实验计算,证实此方法可操作性强,结果更符合实际。     

基于模糊数学法评价滇西保山地区麻榔河泥石流沟的危险性

通过野外实地调查云南省保山市怒江东岸麻榔河泥石流的发育特征,并对其洪积物进行光释光（OSL）测年,认为是一个年轻的泥石流沟,危险性较大。在此基础上,依据泥石流发生的影响因素具有复杂性和模糊性的特点,采用模糊数学法对其危险性进行综合评判。选取7个因子作为泥石流危险度评价的主要关联因子,评价结果与野外调查的实际情况相符,属于中度危险（Ⅲ）。同时指出了评价过程中的2个关键点:建立权重集和确定隶属度。建立权重集的方法采用“理想点”的距离之和极小化为目标来优化确定,隶属度利用半梯形分布模型原理设计隶属函数来实现。经过反复的实验计算,证实此方法可操作性强,结果更符合实际。