Making building codes an effective tool for earthquake hazard mitigation

Abstract

Investigators picking through the debris left by the Northridge earthquake in 1994 and Hurricane Andrew in 1992 found building codes had not provided the degree of protection against damage that many expected. We provide evidence that the problems of code enforcement in the United States that were uncovered for these events are not unique. We show the seismic provisions of codes receive low priority for enforcement by many local building departments, even in areas of moderate to high seismic hazard. Drawing lessons from experience in the United States with programs to foster greater energy efficiency in buildings, we discuss how the federal government and states can make building codes a more effective tool for earthquake hazard mitigation. Although the lessons we draw are specific to the United States, the broader implications of this research concern the role of higher-level governments in motivating local governments to address risks posed by natural hazards.     

Stimulating flood damage mitigation through insurance: an assessment of the French CatNat system

Flood risk has increased in France in the last 20 years and is projected to increase further in the future due to climate change and increase in exposure. Since 1982, France has had a natural disasters insurance system (‘CatNat’) in place that covers flood damage. This insurance system has been combined with what are called ‘Risk Prevention Plans’ (PPRs) in order to stimulate the undertaking of flood risk mitigation measures by communities and households. However, these schemes do not provide optimal incentives for flood damage reduction. This is confirmed by the results from a survey about flood preparedness of 885 households who live in flood-prone areas in France, which are presented in this paper. Moreover, this study provides suggestions for improvement, which are assessed on their potential economic, social and political implications. Among these suggestions are increasing the effectiveness of PPRs and increasing the incentives to apply and implement PPRs; improving the monitoring of the implementation of damage mitigation measures; and the possibility to differentiate premiums and deductibles according to flood risk.     

试论保险公司的洪涝减灾对策

洪涝是危害极为严重的灾种之一，并正在日益加剧。它在给人民生命财产造成巨大损失的同时，也给保险经营构成严重威胁。作者在分析我国洪涝灾害特点和规律的基础上，从保险公司角度提出洪涝的防灾减灾对策，以求把洪涝灾害造成的损失减少到最低程度，实现社会效益和自身效益的双重目标。     

Valuing floodplain protection and avoidance in a coastal watershed

Flood‐related losses in the United States are increasing despite large‐scale mitigation efforts. To offset the rising cost of floods, the US Congress passed legislation in 2014 that will augment insurance premiums to make the National Flood Insurance Program more actuarially sound. Consequently, there is interest in lowering flood‐related costs to the homeowner, both in terms of premiums and damage. This study addresses the issue by integrating premium savings and damages avoided based on several mitigation scenarios. Specifically, it examines how much policyholders within a watershed near Houston, Texas, could have saved between 1999 and 2009 had their communities introduced specific avoidance‐based mitigation activities. The results indicate that homeowners and communities can offset premium rises and a majority of the damage suffered through marginal expansions of such initiatives. However, the costs associated with their implementation could counter some of these savings, and hence they need to be considered in future work.     

美国地震风险评估中灾害模型的探讨

介绍了以美国地震灾害模型为例的地震风险评估在金融保险业和土木工程两大领域的应用,回顾了地震灾害风险评估发展的历史背景,其中,金融保险业的模型更测重于对历史理赔数据的分析,土木工程业的模型则注重于对工程结构的分析。着重探讨了评估模型中地震灾害部分的建立,其中包括致灾因子模块及孕灾环境模块。针对建模中致灾因子、孕灾环境等的关键要素,如地震源及震级、地震衰减方式、场地土壤土质条件、地震复发率等,作了分析及归纳总结,并系统地介绍了所涉及要素的数据信息获取过程及对应的建模方法,进一步探讨了相应的风险量化的步骤和方法。     

Inequalities in exposure and awareness of flood risk in England and Wales

This paper explores the environmental inequalities of living in the floodplains of England and Wales and the differences in flood awareness of those 'at risk'. An area comparison is made between an etic, objective flood risk exposure, and an emic, subjective perception of that risk by social class. In all areas except the Midlands, the working classes were more likely to reside in the floodplains; the greatest exposure inequality is seen in the North East and Anglian regions. Flood awareness in the Anglian regions was much lower than average, but there were no significant class differences. In the Thames region, despite equal flood risk exposure between classes, the most deprived displayed the least awareness of flood risk. In the North East, inequalities in the distribution of flood risk exposure accompanied inequalities in perception, resulting in the least aware and most deprived experiencing the greatest flood risk.     

中国实行洪水保险的可行性研究

在回顾洪水保险实施现状的基础上，指出了我国洪水保险与世界洪水保险的差距，根据我国洪水灾害的特点和我国经济体制的特点，提出了符合我国国情的洪水保险措施：建立洪水保险准备金是进行洪水保险的前提，洪水保险的特殊性决定了洪水保险不可能是个营利性的保险，因此要保证洪水保险的正常运行必须有社会和国家的扶持，洪水保险机构应按流域设立，中国洪水灾害发生的空间特点决定了洪水保险机构只能按流域设置，洪水灾害发生的时间特点决定了洪水保险的对象必须是固定资产，而不应该是流动资产，遭受洪水灾害影响最大的是农田，因此农田应该是洪水保险的对象，不应该是种植在农田里的农作物，另外可以通过农业保险对不同农作物进行保险，洪水保险需要洪水风险的分析和研究作技术支撑，没有科学的洪水风险分析，洪水保险很难顺利进行，加强与洪水保险有关的各方面法律法规的建立，在洪水保险法中明确界定洪水保险的保险对象，明确保险双方的义务和权利。     

西安市防洪工程体系现状及改善措施初探

西安市尽管地处半干旱地区，但洪涝灾害仍是其面临的最大自然灾害之一，它严重地制约着西安市的经济发展和社会稳定。通过对该市防洪工程体系资料的详尽调研，进行了深入具体的分析，提出了防洪工程体系中存在的问题；并通过分析其原因，针对性地提出了相应的具体对策和建议，以提高该市防御洪涝灾害的能力，确保其防洪安全和地区的经济社会发展。     

中国大都市群地区的水灾风险与应急管理研究

在经典风险评价理论模型的基础上,结合自然灾害系统理论,建立了简明水灾综合风险评价模型,完成了中国九大都市群的水灾风险评价.结果表明:我国都市群水灾风险呈现出以都市区中心市为核心的(近)圈层状分布;水灾风险由高到低依次为长三角、珠三角、长江中游、京津唐、吉黑、中原、成渝、辽中南和山东半岛都市群.基于上述研究,强调应建立包含水灾综合风险评价、水灾风险应急预案编制与情景模拟以及水灾风险区划与规划的水灾风险应急管理体系.     

Flood disaster monitoring and evaluation in China

Abstract

China frequently experiences natural disasters, of which flooding is the most serious. How to monitor and control natural disasters, assess damage, and provide relief is the most urgent problem for the Chinese government and disaster experts. A national integrated system using remote sensing, geographic information systems, the Global Positioning System, and other technology for monitoring and evaluating flood disasters has been assembled and tried out for 3 years. The system has played an important role in flood mitigation during the trial and has become a key part of the flood management system at China's National Flood Control Headquarters. This paper presents an overview of the system and its use in China.     

Public involvement in the Red River Basin management decisions and preparedness for the next flood

Abstract

The focus of this study is public participation in the water resource and associated hazards management decision-making processes. It explores the importance, feasibility, and effectiveness of public participation in the flood management, decision-making process, with particular attention to the case of the Red River Basin of Manitoba, Canada. The nature and efficacy of public participation in the hearings conducted by the International Joint Commission (IJC) in the aftermath of the 1997 Red River flood are critically reviewed. The results of the analysis suggest that the IJC has been more sensitive to the views of the public and concerned stakeholders than the Red River Basin Task Force. The IJC incorporated a substantial portion of the opinions, suggestions, and concerns expressed by the public into the final recommendations produced by the commission for the Canadian and American federal governments. Public participation was an integral component of the IJC hearings, and was expected to contribute to flood preparedness in the future. The reasons for such accommodation of public and the stakeholders' views in decision-makingare primarily attributed to making the proposed projects and programs socio-economically and politically feasible. Because of their general characteristics, the lessons from the case of the Red River Basin could be used as an effective tool in other resource and environmental hazard management areas.     

Mapping social vulnerability to flood hazard in Norfolk,England

In this paper, we present a method to assess social vulnerability through the creation of an Open Source Vulnerability Index (OS-VI). The OS-VI provides context to environmental hazards and allows NGOs and local agencies to better tailor services and provide targeted pre-emptive vulnerability reduction and resilience-building programmes. A deductive indicator-based approach is utilised to incorporate a wide range of vulnerability indicators known to influence vulnerability. Unlike many vulnerability indices, the OS-VI incorporates flood risk as well as the loss of capabilities and the importance of key services (health facilities and food stores) through the measurement of accessibility when determining an area's level of social vulnerability. The index was developed using open-source mapping and analysis software and is composed completely of open-source data from national data sets. The OS-VI was designed at the national level, with data for all proxy indicators available across the entirety of England and Wales. For this paper, a case study is presented concerned with one English county, Norfolk.

Highlights

• We produce an open-source vulnerability index.

• Accessibility to health care found to be severely affected by flooding.

• High vulnerability areas found to be disproportionately impacted by flooding.

• Urban extent of an area found to increase its level of vulnerability.

• Flood affected areas more likely to be composed of elderly, sick and poor.

     

苏南地区洪涝危险区的划定及其治理对策

根据水文学和计算水力学的方法，计算出本区１９５４年雨型、现状地面条件下各断面日平均最高水位，同时再综合分析各圩区的堤高、排涝能力及灾害水文等资料，制定出危险圩区的标准。凡不及上述标准的圩区及圩外地区，均划为洪涝危险区，即在遇到大暴雨后，这些地区是可能出现洪涝灾害危险程度最大的地区。     

洪涝灾害经济易损性模糊评价——以安徽沿长江地区为例

洪水灾害是洪水危险性对承灾体易损性综合作用的结果,由于降水量、人口密度、产值等因子在洪水易损性中的作用具有模糊性,因此运用模糊模型进行评价有一定意义。以安徽沿长江地区为例,在GIS和模糊数学法的支持下,建立了基于GIS的模糊综合评价模型,对洪水灾害经济易损性风险进行了评价与分析,将安徽沿长江地区洪涝的易损性程度划分为5个等级:高度易损性、较高度易损性、中度易损性、较低度易损性、低度易损性。研究结果表明:沿江洪水灾害易损性总体水平较高,特别是在马鞍山、芜湖市、铜陵市等经济发达、人口密集、耕地面积广阔的滨江下游平原区。这些地区应积极兴修水利,大力发展避洪产业。     

中国洪水灾害风险区划及其成因分析

洪水灾害风险区划是洪水风险管理的基本依据.长期以来,受数据收集以及分辨率的影响,中国一直缺乏可以指导相关部门进行洪水风险控制及洪水保险的洪灾风险区划.本文利用地理信息系统软件的空间分析模块,基于高分辨率（90m）的全国降雨、地形坡度、河流湖泊缓冲区、人均GDP、人口密度、道路密度和耕地密度等影响水灾发生的风险因子图,采用水灾成因分析法和经验系数法,得到洪水的潜在危险区和经济易损区,进而得到中国洪水灾害风险区划.在此基础上,采用逐步回归法,逐步剔除各影响因子后,对引发洪灾的主要外在驱动力进行了分析.     

Insurance and flood risk reduction in Ghana: do insurers penalise homeowners who take precautionary measures?

Today, many advocate insurance as a tool for coping with natural disasters. Beyond providing prompt financial relief to victims of disasters, insurance can also incentivise individuals to invest in preventive measures if insurers reward such efforts with reduced premiums. However, insurers might be unable to reward investments in precautionary measures with lower premiums if they are ill-informed about individual-level risks. Here, we explore how Ghanaian home insurers respond to investments in flood risk reduction by asking them to quote premiums for four identical buildings; two had investments in flood risk reduction, while the other two had none. We find that insurers did not reward investments in risk reduction, with some charging higher premiums for elevated buildings, suggesting they have interpreted such preventive measures as a sign of high flood risk. This failure to reward investments in precautionary measures may discourage insured homeowners from investing in risk reduction.     

Typhoon hazards in the Shanghai area

There are three major typhoon hazards that apply to the Shanghai area. First, galeforce winds can damage buildings and service facilities. The most severe damage from this occurs only when a typhoon strikes Shanghai directly. Second, both the urban and rural sections of Shanghai are liable to flooding during typhoon seasons. These floods occur when typhoon-induced storm surges coincide with high spring tides and meet with high discharges from the river network as a result of the typhoon downpours. Third, typhoon-induced torrential rain has caused waterlog hazards, particularly in the most densely populated parts of Shanghai. The waterlog hazard has been exacerbated by land subsidence and poor management of pumping systems. In order to prevent disasters happening and reduce the scale of damage, the government has issued construction guidelines and invested in flood defences. Further measures are to be brought in including engineering projects, educational programmes and insurance policies.     

Exploring the spatial dimension of community-level flood risk perception: a cognitive mapping approach

Environmental perceptions are central to individuals’ behavioural interactions with the environment. Cognitive maps, portraying a spatial representation of an individual’s environmental perception, can be aggregated to gain insight into the collective environmental perception of groups and populations. This paper uses cognitive mapping techniques to examine one aspect of environmental perception, flood risk perception, within a residential population (n?=?305). Flood risk perception was examined for the whole sample and six subgroup pairs. Using subgroups allowed examination of how factors previously shown to influence flood risk perception influence the cognitive map production in this population. We use a novel technique (slope analysis) to examine how the population’s perception of flood risk compares with expert assessments of flood risk, and compare the results of this novel technique with a commonly used cognitive map analysis technique (majority threshold method). Both methods identify areas where there is consensus within the population as to which areas are at risk of flooding. However, slope analysis usefully identifies areas where the population’s perception of flood risk lacks consensus, and is at odds with expert assessments of flood risk, without the loss of information inherent in the majority threshold method. Thus, this technique provides a novel approach to studies of environmental perception that can be widely applied within many fields.     

洪水灾害的遥感监测分析系统研究

给出了洪水灾害的遥感监测分析系统,该系统利用遥感信息资料,应用遥感图像处理软件为主要工具,辅助地理信息,分析洪水水情,确定洪灾量级、危害区域及其土地利用类型等,并可比较真实地再现洪灾场景,为防洪规划提供可靠的辅助决策依据。     

Modeling flooding extent from Hurricane Floyd in the coastal plains of North Carolina

Abstract

In this article two modeling approaches were developed based on the use of US Geological Survey digital elevation model (DEM) data. These models were utilized to delineate the extent of flooding induced by precipitation from Hurricane Floyd in a portion of Pitt County, North Carolina. The patterns of flood extent derived from the two models were compared to the extent of flooding indicated on a digital aerial photograph taken two days after peak flood levels had been reached. In addition, floodplain boundaries based on Federal Emergency Management Agency Q3 maps were compared to the extent of flooding on the aerial photo. Actual emergency response operations undertaken through the Pitt County Emergency Operations Center during the flood event are described, and are used to provide a context for evaluating the potential utility of these models. The flood extents produced by the modeling methods performed well at representing the actual extent of the flooding.